YAMAHA WR250FP - Off-road motorcycle

WR250FP - Off-road motorcycle YAMAHA - Free user manual and instructions

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USER MANUAL WR250FP YAMAHA

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This is an electronic backup of the Original Factory Service Manual. You should own the original manual to be able to download this backup.

OWNER'S SERVICE MANUAL

MANUEL D'ATELIER DU

PROPRIETAIRE

FAHRER- UND

WARTUNGS-HANDBUCH

OWNER'S SERVICE MANUAL

©2001 by Yamaha Motor Co., Ltd.

1st Edition, September 2001

All rights reserved.

Any reprinting or unauthorized use

without the written permission of

Yamaha Motor Co., Ltd.

is expressly prohibited.

Printed in Japan

WR250F(P)

MANUEL D'ATELIER

DU PROPRIETAIRE

©2001 Yamaha Motor Co., Ltd.

©2001 by Yamaha Motor Co., Ltd.

Congratulations on your purchase of a Yamaha WR series. This model is the culmination of Yamaha's vast experience in the production of pacesetting racing machines. It represents the highest grade of craftsmanship and reliability that have made Yamaha a leader.

This manual explains operation, inspection, basic maintenance and tuning of your machine. If you have any questions about this manual or your machine, please contact your Yamaha dealer.

NOTE:

As improvements are made on this model, some data in this manual may become outdated. If you have any questions, please consult your Yamaha dealer.

WARNING

PLEASE READ THIS MANUAL CAREFULLY AND COMPLETELY BEFORE OPERATING THIS MACHINE. DO NOT ATTEMPT TO OPERATE THIS MACHINE UNTIL YOU HAVE ATTAINED A SATISFACTORY KNOWLEDGE OF ITS CONTROLS AND OPERATING FEATURES AND UNTIL YOU HAVE BEEN TRAINED IN SAFE AND PROPER RIDING TECHNIQUES. REGULAR INSPECTIONS AND CAREFUL MAINTENANCE, ALONG WITH GOOD RIDING SKILLS, WILL ENSURE THAT YOU SAFETY ENJOY THE CAPABILITIES AND THE RELIABILITY OF THIS MACHINE.

INTRODUCTION

THIS MACHINE IS DESIGNED STRICTLY FOR COMPETITION USE, ONLY ON A CLOSED COURSE. It is illegal for this machine to be operated on any public street, road, or highway. Off-road use on public lands may also be illegal. Please check local regulations before riding.

SAFETY INFORMATION

  1. THIS MACHINE IS TO BE OPERATED BY AN EXPERIENCED RIDER ONLY.

Do not attempt to operate this machine at maximum power until you are totally familiar with its characteristics.

  1. THIS MACHINE IS DESIGNED TO BE RIDDEN BY THE OPERATOR ONLY.

Do not carry passengers on this machine.

  1. ALWAYS WEAR PROTECTIVE APPAREL.

When operating this machine, always wear an approved helmet with goggles or a face shield. Also wear heavy boots, gloves, and protective clothing. Always wear proper fitting clothing that will not be caught in any of the moving parts or controls of the machine.

  1. ALWAYS MAINTAIN YOUR MACHINE IN PROPER WORKING ORDER.

For safety and reliability, the machine must be properly maintained. Always perform the pre-operation checks indicated in this manual. Correcting a mechanical problem before you ride may prevent an accident.

  1. GASOLINE IS HIGHLY FLAMMABLE.

Always turn off the engine while refueling. Take care to not spill any gasoline on the engine or exhaust system. Never refuel in the vicinity of an open flame, or while smoking.

NOTICE IMPORTANTE

If you should swallow some gasoline, inhale excess gasoline vapors, or allow any gasoline to get into your eyes, contact a doctor immediately. If any gasoline spills onto your skin or clothing, immediately wash skin areas with soap and water, and change your clothes.

  1. ONLY OPERATE THE MACHINE IN AN AREA WITH ADEQUATE VENTILA-TION.

Never start the engine or let it run for any length of time in an enclosed area. Exhaust fumes are poisonous. These fumes contain carbon monoxide, which by itself is odorless and colorless. Carbon monoxide is a dangerous gas which can cause unconsciousness or can be lethal.

  1. PARK THE MACHINE CAREFULLY; TURN OFF THE ENGINE.

Always turn off the engine if you are going to leave the machine. Do not park the machine on a slope or soft ground as it may fall over.

  1. THE ENGINE, EXHAUST PIPE, MUFFLER, AND OIL TANK WILL BE VERY HOT AFTER THE ENGINE HAS BEEN RUN.

Be careful not to touch them or to allow any clothing item to contact them during inspection or repair.

  1. PROPERLY SECURE THE MACHINE BEFORE TRANSPORTING IT.

When transporting the machine in another vehicle, always be sure it is properly secured and in an upright position and that the fuel cock is in the “OFF” position. Otherwise, fuel may leak out of the carburetor or fuel tank.

  1. L'ESSENCE PEUT CAUSER DES BLESSURES.

This manual will provide you with a good basic understanding of features, operation, and basic maintenance and inspection items of this machine. Please read this manual carefully and completely before operating your new machine. If you have any questions regarding the operation or maintenance of your machine, please consult your Yamaha dealer.

NOTE:

This manual should be considered a permanent part of this machine and should remain with it even if the machine is subsequently sold.

EC060000

NOTICE

Some data in this manual may become outdated due to improvements made to this model in the future. If there is any question you have regarding this manual or your machine, please consult your Yamaha dealer.

EC070001

F.I.M. MACHINE WEIGHTS:

Weights of machines without fuel

The minimum weights for motocross machines are:

for the class 125 cc...... minimum

88 kg (194 lb)

for the class 250 cc...... minimum

98 kg (216 lb)

for the class 500 cc...... minimum

102 kg (225 lb)

In modifying your machine (e.g., for weight reduction), take note of the above limits of weight.

AU NOUVEAU PROPRIETAIRE

The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS INVOLVED!

YAMAHA WR250FP - AU NOUVEAU PROPRIETAIRE - 1

WARNING

Failure to follow WARNING instructions could result in severe injury or death to the machine operator, a bystander, or a person inspecting or repairing the machine.

CAUTION:

A CAUTION indicates special precautions that must be taken to avoid damage to the machine.

NOTE:

A NOTE provides key information to make procedures easier or clearer.

YAMAHA WR250FP - NOTE: - 1

text_image Line drawing showing hands holding a folded document with numbered pages from 1 to 9

EC082000

FINDING THE REQUIRED PAGE

  1. This manual consists of seven chapters; "General information", "Specifications", "Regular inspection and adjustments", "Engine", "Chassis", "Electrical" and "Tuning".

  2. The table of contents is at the beginning of the manual. Look over the general layout of the book before finding then required chapter and item.

Bend the book at its edge, as shown, to find the required fore edge symbol mark and go to a page for required item and description.

COMMENT UTILISER CE MANUEL

INFORMATIONS PARTICULIEREMENT IMPOR-TANTES

YAMAHA WR250FP - INFORMATIONS PARTICULIEREMENT IMPOR-TANTES - 1

All of the procedures in this manual are organized in a sequential, step-by-step format. The information has been complied to provide the mechanic with an easy to read, handy reference that contains comprehensive explanations of all disassembly, repair, assembly, and inspection operations.

In this revised format, the condition of a faulty component will precede an arrow symbol and the course of action required will follow the symbol, e.g.,

- Bearings

Pitting/damage → Replace.

EC084002

HOW TO READ DESCRIPTIONS

To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each removal and disassembly section.

  1. An easy-to-see exploded diagram ① is provided for removal and disassembly jobs.
  2. Numbers ② are given in the order of the jobs in the exploded diagram. A number that is enclosed by a circle indicates a disassembly step.
  3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol marks ③. The meanings of the symbol marks are given on the next page.
  4. A job instruction chart ④ accompanies the exploded diagram, providing the order of jobs, names of parts, notes in jobs, etc.
  5. Extent of removal ⑤ is provided in the job instruction chart to save the trouble of an unnecessary removal job.
  6. For jobs requiring more information, the step-by-step format supplements ⑥ are given in addition to the exploded diagram and job instruction chart.

YAMAHA WR250FP - HOW TO READ DESCRIPTIONS - 1

text_image CLUTCH CLUTCH ① ② ③ ④ ⑤ CLUTCH ENG 15 New 23 × 10Nm (1.0m kg,7.2ft-lb) × 10Nm (1.0m kg,7.2ft-lb) × 75Nm (7.5m kg,54ft-lb) × 8Nm (0.8m kg,5.8ft-lb) 16 21 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 3 4 5 6 7 8 9 10 11 ① Push rod and push lever removal ② Push pod 1 disassembly ③ Friction plate and clutch plate removal ④ Clutch housing removal Extent of removal: Order Part name Q'ty Remarks Preparation for removal CLUTCH REMOVAL Drain the engine oil. Brake pedal Clutch cable Refer to "ENGINE OIL REPLACEMENT" section in the CHAPTER 3. Refer to "ENGINE REMOVAL" section. Disconnect at engine side. 1 1 2 Gasket 1 3 Dowel pin 2 4 Clutch spring 6 5 Pressure plate 1 6 Push rod 1 1 7 Circlip 1 8 Plain washer 1 9 Bearing 1 10 Ball 1 11 Push rod 2 1

4 - 45

YAMAHA WR250FP - HOW TO READ DESCRIPTIONS - 2

text_image CLUTCH ENG EC493000 REMOVAL POINTS EC485211 Clutch boss 1. Remove: • Nut ① • Lock washer ② • Clutch boss ③ NOTE: _ Straighten the lock washer tab and use the clutch holding tool ④ to hold the clutch boss. A B Clutch holding tool: YM-91042/90890-04086 A For USA and CDN B Except for USA and CDN EC494000 INSPECTION EC484100 Clutch housing and boss 1. Inspect: • Clutch housing ① Cracks/wear/damage → Replace. • Clutch boss ② Scoring/wear/damage → Replace. EC484001 Primary driven gear 1. Check: • Circumferential play Free play exists → Replace. • Gear teeth ④ Wear/damage → Replace. EC484002 Clutch spring 1. Measure: • Clutch spring free length ⑧ Out of specification → Replace springs as a set. [1132M] Clutch spring free length: Standard 50 mm (1.97 in) 49 mm (1.93 in)

4 - 47

FORMAT DU MANUEL

ILLUSTRATED SYMBOLS (Refer to the illustration)

Illustrated symbols ① to ⑦ are designed as thumb tabs to indicate the chapter's number and content.

① General information
② Specifications
③ Regular inspection and adjustments
④ Engine
⑤ Chassis
⑥ Electrical
⑦ Tuning

Illustrated symbols ⑧ to ⑭ are used to identify the specifications appearing in the text.

⑧ With engine mounted
⑨ Special tool
⑩ Filling fluid
⑪ Lubricant
⑫ Tightening
⑬ Specified value, Service limit
⑭ Resistance (Ω), Voltage (V), Electric current (A)

Illustrated symbols ⑮ to ⑱ in the exploded diagrams indicate grade of lubricant and location of lubrication point.

⑮ Apply engine oil
⑯ Apply molybdenum disulfide oil
⑰ Apply lightweight lithium-soap base grease
⑱ Apply molybdenum disulfide grease

Illustrated symbols ⑲ to ⑳ in the exploded diagrams indicate where to apply a locking agent and where to install new parts.

⑲ Apply locking agent (LOCTITE®)
⑳ Use new one

SYMBOLES GRAPHI- QUES

CHECKING OF CONNECTION 1-6

SPECIAL TOOLS 1-7

CONTROL FUNCTIONS 1-10

FUEL 1-14

STARTING AND BREAK-IN 1-15

TORQUE-CHECK POINTS 1-19

CLEANING AND STORAGE 1-20

CHAPTER 2

SPECIFICATIONS

GENERAL SPECIFICATIONS ...... 2-1

MAINTENANCE SPECIFICATIONS ...... 2-4

GENERAL TORQUE

SPECIFICATIONS 2-18

DEFINITION OF UNITS 2-18

CABLE ROUTING DIAGRAM 2-19

CHAPTER 3

REGULAR INSPECTION AND ADJUSTMENTS

MAINTENANCE INTERVALS 3-1

CONNEXIONS ...... 1-6

OUTILS SPECIAUX ....1-7

FONCTIONS DES

COMMANDES 1-10

ESSENCE 1-14

MISE EN MARCHE

ET RODAGE 1-15

POINTS DE VERIFICATION DE

COUPLE DE SERRAGE ...... 1-19

NETTOYAGE ET

RANGEMENT 1-20

CHAPITRE 2 CARACTERISTIQUES

CARACTERISTIQUES

GENERALES 2-1

CARACTERISTIQUES

D'ENTRETIEN 2-4

CARACTERISTIQUES

GENERALES DE COUPLE .....2-18

DEFINITION DES UNITES .....2-18

CHEMINEMENT DES

CABLES 2-19

CHAPITRE 3 CONTROLES ET REGLAGES COURANTS

PROGRAMME D'ENTRETIEN ..3-1

CONTROLE ET ENTRETIEN

AVANT UTILISATION ....3-4

MOTEUR 3-5

PARTIE CYCLE ......3-26

PARTIE ELECTRIQUE ......3-47

INHALT

CYLINDER AND PISTON 4-43

CLUTCH 4-50

OIL FILTER ELEMENT, WATER PUMP

AND RIGHT CRANKCASE COVER ..... 4-57

BALANCER 4-64

OIL PUMP 4-67

KICK SHAFT AND SHIFT SHAFT ...... 4-72

CDI MAGNETO 4-79

ENGINE REMOVAL 4-83

CRANKCASE AND CRANKSHAFT ..... 4-88

TRANSMISSION, SHIFT CAM

AND SHIFT FORK 4-97

CHAPTER 5 CHASSIS

FRONT WHEEL AND REAR WHEEL ..... 5-1

FRONT BRAKE AND REAR BRAKE ..... 5-11

FRONT FORK 5-28

HANDLEBAR 5-41

STEERING 5-47

SWINGARM 5-53

REAR SHOCK ABSORBER 5-60

CHAPITRE 4 MOTEUR

SELLE, RESERVOIR

DE CARBURANT ET

CACHES LATERAUX ....4-1

TUYAU D'ECHAPPEMENT

ET SILENCIEUX 4-2

RADIATEUR 4-4

CARBURATEUR 4-7

ARBRES A CAMES ......4-21

CULASSE 4-30

SOUPAPES ET RESSORTS

DE SOUPAPE 4-34

CYLINDRE ET PISTON ......4-43

EMBRAYAGE 4-50

ELEMENT DE FILTRE A

HUILE, POMPE A EAU ET

DEMI-CARTER DROIT ......4-57

BALANCIER 4-64

POMPE A HUILE 4-67

FOURCHE AVANT ....5-28

GUIDON 5-41

DIRECTION 5-47

BRAS OSCILLANT ....5-53

AMORTISSEUR ARRIERE .....5-60

KAPITEL 5 FAHRWERK

VORDER- UND HINTERRAD ....5-1

VORDER- UND

HINTERRADBREMSE ....5-11

TELESKOPGABEL 5-28

LENKER 5-41

LKKOPF 5-47

SCHWINGE 5-53

FEDERBEIN 5-60

CAPITOLO 5 PARTE CICLISTICA

RUOTA ANTERIORE E RUOTA

POSTERIORE 5-1

FRENO ANTERIORE E

POSTERIORE 5-11

FORCELLA ANTERIORE .....5-28

MANUBRIO 5-41

STERZO 5-47

FORCELLONE

OSCILLANTE ....5-53

AMMORTIZZATORE

POSTERIORE 5-60

CHAPTER 6 ELECTRICAL

ELECTRICAL COMPONENTS
AND WIRING DIAGRAM 6-1
MAP-CONTROLLED CDI UNIT 6-2
IGNITION SYSTEM 6-3
THROTTLE POSITION SENSOR
SYSTEM 6-7
LIGHTING SYSTEM 6-12

CHAPTER 7 TUNING

ENGINE 7-1

CHASSIS 7-12

CHAPITRE 6 PARTIE ELECTRIQUE

COMPOSANTS ELECTRIQUES ET SCHEMA DE CABLAGE .....6-1 BLOC CDI CONTROLE PAR MICROPROCESSEUR .....6-2 SYSTEME D'ALLUMAGE .....6-3 CIRCUIT DU CAPTEUR DE PAPILLON DES GAZ .....6-7 SYSTEME D'ECLAIRAGE .....6-12

CHAPITRE 7 MISES AU POINT

MOTEUR ....7-1 PARTIE CYCLE ....7-12

① Clutch lever
② Decompression lever
③ Trip meter
④ Light switch
⑤ Front brake lever
⑥ Throttle grip
⑦ Radiator cap
⑧ Fuel tank cap
⑨ Oil tank cap
⑩ Engine stop switch
⑪ Taillight
⑫ Kickstarter crank
⑬ Fuel tank
⑭ Headlight
⑮ Radiator
⑯ Coolant drain bolt
⑰ Rear brake pedal
⑱ Valve joint
⑲ Fuel cock
⑳ Cold starter knob
②1 Hot starter knob (red)
⑳ Drive chain
②3 Air filter
⑳ Shift pedal
⑲ Front fork

YAMAHA WR250FP - CHAPITRE 7 MISES AU POINT - 1

text_image Technical diagram of a motorcycle with numbered components for identification

NOTE:

  • The machine you have purchased may differ slightly from those shown in the following.
  • Designs and specifications are subject to change without notice.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a motorcycle body with numbered parts for identification

YAMAHA WR250FP - NOTE: - 2

text_image Technical diagram of a motorcycle with numbered parts for identification

RENSEIGNEMENTS GENERAUX DESCRIPTION

There are two significant reasons for knowing the serial number of your machine:

  1. When ordering parts, you can give the number to your Yamaha dealer for positive identification of the model you own.
  2. If your machine is stolen, the authorities will need the number to search for and identify your machine.

EC121001

VEHICLE IDENTIFICATION NUMBER

The vehicle identification number ① is stamped on the right of the steering head pipe.

YAMAHA WR250FP - VEHICLE IDENTIFICATION NUMBER - 1

text_image Technical diagram of a vehicle's engine compartment with numbered parts labeled ① and ⑤

YAMAHA WR250FP - VEHICLE IDENTIFICATION NUMBER - 2

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - VEHICLE IDENTIFICATION NUMBER - 3

text_image Technical diagram of a mechanical assembly with labeled component 1

EC123001

ENGINE SERIAL NUMBER

The engine serial number ① is stamped into the elevated part of the right-side of the engine.

EC124000

MODEL LABEL

The model label ① is affixed to the frame under the rider's seat. This information will be needed to order spare parts.

IDENTIFICATION DE LA MACHINE

natural_image Cartoon illustration of a person washing a motorcycle with buckets nearby (no text or symbols)

YAMAHA WR250FP - IDENTIFICATION DE LA MACHINE - 1

natural_image Four-panel line drawing showing insect head and mechanical components, no text or symbols present

YAMAHA WR250FP - IDENTIFICATION DE LA MACHINE - 2

natural_image Cartoon illustration of a mechanic working on a motorcycle with tools (no text or symbols)

YAMAHA WR250FP - IDENTIFICATION DE LA MACHINE - 3

natural_image Cartoon illustration of a smiling worker holding a tool near a device (no text or symbols)

YAMAHA WR250FP - IDENTIFICATION DE LA MACHINE - 4

natural_image Cartoon illustration of a man sitting with arms crossed, surrounded by stacks of coins and a question mark above (no text or symbols)

EC130000 IMPORTANT INFORMATION

EC131010 PREPARATION FOR REMOVAL AND DISASSEMBLY

  1. Remove all dirt, mud, dust, and foreign material before removal and disassembly.

When washing the machine with high pressured water, cover the parts follows.

  • Silencer end
    • Air filter intake hole
    • Water pump housing hole at the bottom
    • Carburetor accelerator pump

  • Use proper tools and cleaning equipment. Refer to "SPECIAL TOOLS" section.

  • When disassembling the machine, keep mated parts together. They include gears, cylinders, pistons, and other mated parts that have been “mated” through normal wear. Mated parts must be reused as an assembly or replaced.
  • During the machine disassembly, clean all parts and place them in trays in the order of disassembly. This will speed up assembly time and help assure that all parts are correctly reinstalled.
  • Keep away from fire.

INFORMATIONS IMPOR- TANTES PREPARATION POUR LA DEPOSE ET DEMONTAGE

ALL REPLACEMENT PARTS

  1. We recommend to use Yamaha genuine parts for all replacements. Use oil and/or grease recommended by Yamaha for assembly and adjustment.

EC133000

GASKETS, OIL SEALS AND O-RINGS

  1. All gaskets, oil seals, and O-rings should be replaced when an engine is overhauled. All gasket surfaces, oil seal lips, and O-rings must be cleaned.
  2. Properly oil all mating parts and bearings during reassembly. Apply grease to the oil seal lips.

YAMAHA WR250FP - GASKETS, OIL SEALS AND O-RINGS - 1

text_image Technical diagram showing two bolted components and a fastener assembly with labeled connection point 1

YAMAHA WR250FP - GASKETS, OIL SEALS AND O-RINGS - 2

text_image Technical diagram of a mechanical valve assembly with labeled component ①

YAMAHA WR250FP - GASKETS, OIL SEALS AND O-RINGS - 3

text_image Technical mechanical diagram showing a cross-sectional view with labeled component ② and directional arrow

EC134000

LOCK WASHERS/PLATES AND COTTER PINS

  1. All lock washers/plates ① and cotter pins must be replaced when they are removed. Lock tab(s) should be bent along the bolt or nut flat(s) after the bolt or nut has been properly tightened.

EC135001

BEARINGS AND OIL SEALS

  1. Install the bearing(s) ① and oil seal(s) ② with their manufacturer's marks or numbers facing outward. (In other words, the stamped letters must be on the side exposed to view.) When installing oil seal(s), apply a light coating of lightweight lithium base grease to the seal lip(s). Oil the bearings liberally when installing.

CAUTION:

Do not use compressed air to spin the bearings dry. This causes damage to the bearing surfaces.

PIECES DE RECHANGE

text_image Technical diagram showing a mechanical or structural assembly with numbered components and directional arrows indicating flow or movement.

EC136000

CIRCLIPS

  1. All circlips should be inspected carefully before reassembly. Always replace piston pin clips after one use. Replace distorted circlips. When installing a circlip ①, make sure that the sharp-edged corner ② is positioned opposite to the thrust ③ it receives. See the sectional view.

④ Shaft

CIRCLIPS

natural_image Two-panel line drawing showing a hand holding a tool, with no text or symbols present.

YAMAHA WR250FP - CIRCLIPS - 1

text_image Technical diagram showing two-step assembly steps for a mechanical tool or device, with labeled component '①'

YAMAHA WR250FP - CIRCLIPS - 2

natural_image Diagram of electrical connections with wires, a multimeter, and two cables (no text or symbols)

YAMAHA WR250FP - CIRCLIPS - 3

natural_image Diagram of a hand connecting two cables to a plug and a multimeter (no text or symbols present)

EC1C0001

CHECKING OF CONNECTION

Dealing with stains, rust, moisture, etc. on the connector.

  1. Disconnect:

- Connector

  1. Dry each terminal with an air blower.

  2. Connect and disconnect the connector two or three times.

  3. Pull the lead to check that it will not come off.

  4. If the terminal comes off, bend up the pin ① and reinsert the terminal into the connector.

  5. Connect:

- Connector

NOTE:

The two connectors "click" together.

  1. Check for continuity with a tester.

NOTE:

  • If there in no continuity, clean the terminals.
  • Be sure to perform the steps 1 to 7 listed above when checking the wire harness.
  • For a field remedy, use a contact revitalizer available on the market.
  • Use the tester on the connector as shown.

VERIFICATION DES CONNEXIONS

The proper special tools are necessary for complete and accurate tune-up and assembly. Using the correct special tool will help prevent damage caused by the use of improper tools or improvised techniques. The shape and part number used for the special tool differ by country, so two types are provided. Refer to the list provided to avoid errors when placing an order.

NOTE:

  • For U.S.A. and Canada, use part number starting with "YM-", "YU-" or "ACC-".
  • For others, use part number starting with "90890-".
Part numberTool name/How to useIllustration
YU-1135-A, 90890-01135Crankcase separating toolThese tool is used to remove the crankshaft from either case.YU-1135-AYAMAHA WR250FP - NOTE: - 190890-01135[YYYYA]
YU-1235, 90890-01235Rotor holding toolThis tool is used when loosening or tightening the fly-wheel magneto securing nut.YU-1235YAMAHA WR250FP - NOTE: - 290890-01235YAMAHA WR250FP - NOTE: - 3
YU-3097, 90890-01252YU-1256Dial gauge and standStandThese tools are used to check each part for runout or bent.YU-3097YU-1256YAMAHA WR250FP - NOTE: - 4,90890-01252YAMAHA WR250FP - NOTE: - 5
YU-90050, 90890-01274YU-90050, 90890-01275YU-91044, 90890-04081YM-1277, 90890-01277Crankshaft installing toolCrankshaft installing potCrankshaft installing boltSpacer (crankshaft installer)Adapter (M10)These tools are used to install the crankshaft.YU-90050YM-1277YU-{YAMAHA WR250FP - NOTE: - 6}90890-0127490890-0127590890-90890-YAMAHA WR250FP - NOTE: - 7)
YU-1304, 90890-01304Piston pin puller setThis tool is used to remove the piston pin.YU-1304YAMAHA WR250FP - NOTE: - 890890-01304YAMAHA WR250FP - NOTE: - 9
YU-24460-01, 90890-01325YU-33984, 90890-01352Radiator cap testerRadiator cap tester adapterThese tools are used for checking the cooling system.YU-24460-01YU-33984YAMAHA WR250FP - NOTE: - 1090890-0132590890-01352YAMAHA WR250FP - NOTE: - 11
YU-33270-B, 90890-01362Flywheel pullerThis tool is used to remove the flywheel magneto.YM-33270-BYAMAHA WR250FP - NOTE: - 1290890-01362YAMAHA WR250FP - NOTE: - 13
YU-33975, 90890-01403Steering nut wrenchThis tool is used when tighten the steering ring nut to specification.YU-33975YAMAHA WR250FP - NOTE: - 1490890-01403YAMAHA WR250FP - NOTE: - 15
YM-1423, 90890-01423Damper rod holderUse this tool to remove and install the damper rod.YM-1423YAMAHA WR250FP - NOTE: - 1690890-01423YAMAHA WR250FP - NOTE: - 17
YM-01442, 90890-01442Fork seal driverThis tool is used when install the fork oil seal.YM-01442YAMAHA WR250FP - NOTE: - 1890890-01442YAMAHA WR250FP - NOTE: - 19
YU-3112-C, 90890-03112Pocket testerUse this tool to inspect the coil resistance, output voltage and amperage.YU-3112-CYAMAHA WR250FP - NOTE: - 2090890-03112YAMAHA WR250FP - NOTE: - 21
YU-8036-B90890-03113Inductive tachometerEngine tachometerThis tool is needed for observing engine rpm.YU-8036-BYAMAHA WR250FP - NOTE: - 2290890-03113YAMAHA WR250FP - NOTE: - 23
YM-33277-A, 90890-03141Timing lightThis tool is necessary for checking ignition timing.YM-33277-AYAMAHA WR250FP - NOTE: - 2490890-03141YAMAHA WR250FP - NOTE: - 25
YM-4019, 90890-04019Valve spring compressorThis tool is needed to remove and install the valve assemblies.YM-4019YAMAHA WR250FP - NOTE: - 2690890-04019YAMAHA WR250FP - NOTE: - 27
YM-91042, 90890-04086Clutch holding toolThis tool is used to hold the clutch when removing or installing the clutch boss securing nut.YM-91042YAMAHA WR250FP - NOTE: - 2890890-04086YAMAHA WR250FP - NOTE: - 29
YM-4111, 90890-04111YM-4116, 90890-04116Valve guide removerIntake 4.0 mm (0.16 in)Exhaust 4.5 mm (0.18 in)This tool is needed to remove and install the valve guide.YM-4111YM-4116YAMAHA WR250FP - NOTE: - 3090890-0411190890-04116YAMAHA WR250FP - NOTE: - 31
YM-4112, 90890-04112YM-4117, 90890-04117Valve guide installerIntake 4.0 mm (0.16 in)Exhaust 4.5 mm (0.18 in)This tool is needed to install the valve guide.YM-4112YM-41YAMAHA WR250FP - NOTE: - 3290890-0411290890-(YAMAHA WR250FP - NOTE: - 33
YM-4113, 90890-04113YM-4118, 90890-04118Valve guide reamerIntake 4.0 mm (0.16 in)Exhaust 4.5 mm (0.18 in)This tool is needed to rebore the new valve guide.YM-4113 YAMAHA WR250FP - NOTE: - 3490890-04113§YAMAHA WR250FP - NOTE: - 35
YM-3448790890-06754Dynamic spark testerIgnition checkerThis instrument is necessary for checking the ignition system components.YM-34487YAMAHA WR250FP - NOTE: - 3690890-06754YAMAHA WR250FP - NOTE: - 37
ACC-QUICK-GS-KT90890-85505Quick gasket®YAMAHA Bond No. 1215This sealant (Bond) is used for crankcase mating surface, etc.ACC-QUICK-GS-KTYAMAHA WR250FP - NOTE: - 3890890-85505YAMAHA WR250FP - NOTE: - 39

OUTILS SPECIAUX

text_image Technical diagram of a bicycle steering mechanism with labeled parts and numbered component

YAMAHA WR250FP - OUTILS SPECIAUX - 1

text_image Technical diagram of a bicycle steering mechanism with labeled parts and numbered callouts

YAMAHA WR250FP - OUTILS SPECIAUX - 2

text_image 5 4 3 2 N 1

YAMAHA WR250FP - OUTILS SPECIAUX - 3

text_image Technical diagram of a mechanical assembly with labeled component ①

EC150000

CONTROL FUNCTIONS

ENGINE STOP SWITCH

The engine stop switch ① is located on the left handlebar. Continue pushing the engine stop switch till the engine comes to a stop.

EC152000

CLUTCH LEVER

The clutch lever ① is located on the left handlebar; it disengages or engages the clutch. Pull the clutch lever to the handlebar to disengage the clutch, and release the lever to engage the clutch. The lever should be pulled rapidly and released slowly for smooth starts.

EC153000

SHIFT PEDAL

The gear ratios of the constant-mesh 5 speed transmission are ideally spaced. The gears can be shifted by using the shift pedal ① on the left side of the engine.

KICKSTARTER CRANK

Rotate the kickstarter crank ① away from the engine. Push the starter down lightly with your foot until the gears engage, then kick smoothly and forcefully to start the engine. This model has a primary kickstarter crank so the engine can be started in any gear if the clutch is disengaged. In normal practices, however, shift to neutral before starting.

natural_image Technical line drawing of a mechanical clamp or grip assembly (no text or symbols)

DECOMPRESSION LEVER

CAUTION:

Never use the decompression lever after the engine is started. The engine may be damaged if you use the decompression lever while it is running.

The decompression lever ① is located on the left handlebar and is used when starting the engine. Squeezing the decompression lever presses down on the exhaust valve and releases the pressure in the cylinder head. This enables the vehicle to be kickstarted more easily.

YAMAHA WR250FP - CAUTION: - 1

text_image Diagram illustrating fluid flow through a pipe with labeled component ① and directional arrows indicating flow direction.

EC155001

THROTTLE GRIP

The throttle grip ① is located on the right handlebar; it accelerates or decelerates the engine. For acceleration, turn the grip toward you; for deceleration, turn it away from you.

YAMAHA WR250FP - THROTTLE GRIP - 1

text_image Technical diagram of a mechanical assembly with labeled component ①

EC156000

FRONT BRAKE LEVER

The front brake lever ① is located on the right handlebar. Pull it toward the handlebar to activate the front brake.

YAMAHA WR250FP - FRONT BRAKE LEVER - 1

text_image 1 C C YAKARA

EC157000

REAR BRAKE PEDAL

The rear brake pedal ① is located on the right side of the machine. Press down on the brake pedal to activate the rear brake.

LEVIER DE DECOMPRESSION

ATTENTION:

The fuel cock supplies fuel from the tank to carburetor while filtering the fuel. The fuel cock has the three positions:

OFF: With the lever in this position, fuel will not flow. Always return the lever to this position when the engine is not running.

ON: With the lever in this position, fuel flows to the carburetor. Normal riding is done with the lever in this position.

RES: This indicates reserve. If you run out of fuel while riding, move the lever to this position. FILL THE TANK AT THE FIRST OPPORTUNITY. BE SURE TO SET THE LEVER TO "ON" AFTER REFUELING.

YAMAHA WR250FP - ATTENTION: - 1

text_image Technical diagram of a vehicle suspension system with labeled components and directional arrows indicating motion or movement.

COLD STARTER KNOB

When cold, the engine requires a richer air-fuel mixture for starting. A separate starter circuit, which is controlled by the cold starter knob ①, supplies this mixture. Pull the cold starter knob out to open the circuit for starting. When the engine has warmed up, push it in to close the circuit.

YAMAHA WR250FP - COLD STARTER KNOB - 1

text_image Technical diagram of automotive suspension system components with numbered parts and labeled parts

HOT STARTER KNOB

The hot starter knob (red) ① is used when starting a warm engine.

Use the hot starter knob when starting the engine again immediately after it was stopped (the engine is still warm). Pulling out the hot starter knob injects secondary air to thin the air-fuel mixture temporarily, allowing the engine to be started more easily.

CAUTION:

After the engine has started, be sure to push the hot starter knob back in.

ROBINET DE CARBURANT

natural_image Technical line drawing of a mechanical assembly with hoses and connectors (no text or symbols)

YAMAHA WR250FP - ROBINET DE CARBURANT - 1

text_image Technical diagram showing a mechanical assembly with labeled component ①, including a close-up inset of a rectangular component.

EC15F000

VALVE JOINT

This valve joint ① prevents fuel from flowing out and is installed to the fuel tank breather hose.

CAUTION:

In this installation, make sure the arrow faces the fuel tank and also downward.

LIGHTS SWITCH

The lights switch ① is located on the handlebar.

FLAP

In order to prevent water from entering the carburetor while the machine is operated in the rain, attach the accessory flap ① to the frame at the rear of the fuel tank.

NOTE:

Riding with the flap attached when it is not raining can help keep out dust, dirt and sand.

FONCTIONS DES COMMANDES ARMATUREN UND DEREN FUNKTION FUNZIONI DI COMANDO

YAMAHA WR250FP - FONCTIONS DES COMMANDES ARMATUREN UND DEREN FUNKTION FUNZIONI DI COMANDO - 1

CLAPET DE DURIT DE MISE A LIAIR

Always use the recommended fuel as stated below. Also, be sure to use new gasoline the day of a race.

YAMAHA WR250FP - CLAPET DE DURIT DE MISE A LIAIR - 1

Recommended fuel:

Except for ZA:

Premium unleaded gasoline only with a research octane number of 95 or higher.

For ZA:

Premium gasoline

CAUTION:

Use only unleaded gasoline. The use of leaded gasoline will cause severe damage to the engine internal parts such as valves, piston rings, and exhaust system, etc.

NOTE:

If knocking or pinging occurs, use a different brand of gasoline or higher octane grade.

ESSENCE

Never start or run the engine in a closed area. The exhaust fumes are poisonous; they can cause loss of consciousness and death in a very short time. Always operate the machine in a well-ventilated area.

CAUTION:

  • The carburetor on this motorcycle has a built-in accelerator pump. Therefore, when starting the engine, do not operate the throttle or the spark plug will foul.
  • Unlike a two-stroke engine, this engine cannot be kick started when the throttle is open because the kick starter may kick back. Also, if the throttle is open the air/fuel mixture may be too lean for the engine to start.
  • Never use the decompression lever after the engine is started. The engine may be damaged if you use the decompression lever while it is running.
  • Before starting the machine, perform the checks in the pre-operation check list.

STARTING A COLD ENGINE

  1. Inspect the coolant level.
  2. Turn the fuel cock to "ON".
  3. Shift the transmission into neutral.
  4. Fully open the cold starter knob.
  5. Without pulling in the decompression lever, slowly depress the kickstarter crank until the compression stroke is found. When considerable resistance of the kickstarter crank is felt, the engine is on the compression stroke. If the engine is on the exhaust stroke, resistance will only be felt when the kickstarter crank is initially depressed, not through the entire range of depression (as when the engine is on the compression stroke); therefore, depress the kickstarter crank a few more times.

Do not open the throttle while kicking the kickstarter crank. Otherwise, the kick starter may kick back.

  1. Return the cold starter knob to its original position and run the engine at 3,000 \~ 5,000 r/min for 1 or 2 minutes.

NOTE:

Since this model is equipped with an accelerator pump, if the engine is raced (the throttle opened and closed), the air/fuel mixture will be too rich and the engine may stall. Also unlike a two-stroke engine, this model can idle.

CAUTION:

Do not warm up the engine for extended periods of time.

MISE EN MARCHE ET RODAGE ANLASSEN UND EINFAHREN AVVIO E RODAGGIO

YAMAHA WR250FP - MISE EN MARCHE ET RODAGE ANLASSEN UND EINFAHREN AVVIO E RODAGGIO - 1

Do not operate the cold starter knob and throttle. Open the hot starter knob (red) and start the engine by kicking the kickstarter crank forcefully with a firm stroke.

As soon as the engine starts, push in the hot starter knob to close the air passage.

Restarting an engine after a fall

Pull the hot starter knob (red) and start the engine. As soon as the engine starts, push in the hot starter knob to close the air passage.

The engine fails to start

Pull the hot starter knob (red) all the way out, pull the decompression lever to the handlebar, and while holding the lever, kick the kickstarter crank 10 to 20 times to clear the engine.

Then, restart the engine.

Refer to "Restarting an engine after a fall".

Throttle grip operation*Cold starter knobHot starter knob (red)
Starting a cold engineAir temperature = less than 5 °C (41 °F)Open 3 or 4 timesONOFF
Air temperature = more than 5 °C (41 °F)NoneONOFF
Air temperature (normal temperature) = between 5 °C (41 °F) and 25 °C (77 °F)NoneON/OFFOFF
Air temperature = more than 25 °C (77 °F)NoneOFFOFF
Starting an engine after a long period of timeNoneONOFF
Restarting a warm engineNoneOFFON
Restarting an engine after a fallNoneOFFON

* Operate the throttle grip before kick starting.

CAUTION:

Observe the following break-in procedures during initial operation to ensure optimum performance and avoid engine damage.

MISE EN MARCHE D'UN MOTEUR CHAUD

  1. Before starting the engine, fill the fuel tank with the fuel.
  2. Perform the pre-operation checks on the machine.
  3. Start and warm up the engine. Check the idle speed, and check the operation of the controls and the engine stop switch. Then, restart the engine and check its operation within no more than 5 minutes after it is restarted.
  4. Operate the machine in the lower gears at moderate throttle openings for five to eight minutes.
  5. Check how the engine runs when the motorcycle is ridden with the throttle 1/4 to 1/2 open (low to medium speed) for about one hour.
  6. Restart the engine and check the operation of the machine throughout its entire operating range. Restart the machine and operate it for about 10 to 15 more minutes. The machine will now be ready to race.

CAUTION:

  • After the break-in or before each race, you must check the entire machine for loose fittings and fasteners as per "TORQUE-CHECK POINTS".
    Tighten all such fasteners as required.
  • When any of the following parts have been replaced, they must be broken in. CYLINDER AND CRANKSHAFT:
    About one hour of break-in operation is necessary.
    PISTON, RING, VALVES, CAMSHAFTS AND GEARS:
    These parts require about 30 minutes of break-in operation at half-throttle or less. Observe the condition of the engine carefully during operation.

PROCEDURE DE RODAGE

PISTONS, SEGMENTS, SOUPAPES, ARBRES A CAMES ET PIGNONS:

EINFAHRVORSCHRIFTEN

flowchart
graph TD
    A["Frame construction"] --> B["Combined seat and fuel tank"]
    B --> C["Frame to rear frame"]
    B --> D["Fuel tank to frame"]
    E["Exhaust system"] --> F["Silencer to rear frame"]
    G["Engine mounting"] --> H["Frame to engine"]
    H --> I["Engine bracket to engine"]
    H --> J["Engine bracket to frame"]
    K["Steering"] --> L["Steering stem to handlebar"]
    L --> M["Steering stem to frame"]
    L --> N["Steering stem to upper bracket"]
    L --> O["Upper bracket to handlebar"]
    P["Suspension"] --> Q["Front"]
    P --> R["Steering stem to front fork"]
    R --> S["Front fork to upper bracket"]
    R --> T["Front fork to lower bracket"]
    U["Rear"] --> V["For link type"]
    V --> W["Assembly of links"]
    V --> X["Link to frame"]
    V --> Y["Link to rear shock absorber"]
    V --> Z["Link to swingarm"]
    U --> AA["Rear"]
    AA --> AB["Installation of rear shock absorber"]
    AB --> AC["Rear shock absorber to frame"]
    AB --> AD["Tightening of pivot shaft"]
    AE["Rear"] --> AF["Installation of swing-arm"]
    AF --> AG["Tightening of wheel axle"]
    AF --> AH["Tightening of axle holder"]
    AF --> AI["Tightening of wheel axle"]
    AF --> AJ["Wheel to rear wheel sprocket"]
    AK["Wheel"] --> AL["Installation of wheel"]
    AL --> AM["Front"]
    AL --> AN["Rear"]
    AN --> AO["Tightening of wheel axle"]
    AN --> AP["Tightening of axle holder"]
    AN --> AQ["Tightening of wheel axle"]
    AN --> AR["Wheel to rear wheel sprocket"]
    AS["Brake"] --> AT["Front"]
    AT --> AU["Brake caliper to front fork"]
    AT --> AV["Brake disc to wheel"]
    AT --> AW["Tightening of union bolt"]
    AT --> AX["Brake master cylinder to handlebar"]
    AT --> AY["Tightening of bleed screw"]
    AS --> AZ["Rear"]
    AZ --> BA["Brake pedal to frame"]
    AZ --> BB["Brake disc to frame"]
    AZ --> BC["Tightening of union bolt"]
    AZ --> BD["Brake master cylinder to frame"]
    AZ --> BE["Tightening of bleed screw"]
    BF["Fuel system"] --> BG["Fuel tank to fuel cock"]

NOTE:

Concerning the tightening torque, refer to "MAINTENANCE SPECIFICATIONS" section in the CHAPTER 2.

POINTS DE VERIFICATION DE COUPLE DE SERRAGE
YAMAHA WR250FP - NOTE: - 1

CLEANING AND STORAGE

EC1B1000

CLEANING

Frequent cleaning of your machine will enhance its appearance, maintain good overall performance, and extend the life of many components.

  1. Before washing the machine, block off the end of the exhaust pipe to prevent water from entering. A plastic bag secured with a rubber band may be used for this purpose.
  2. If the engine is excessively greasy, apply some degreaser to it with a paint brush. Do not apply degreaser to the chain, sprockets, or wheel axles.
  3. Rinse the dirt and degreaser off with a garden hose; use only enough pressure to do the job.

CAUTION:

Excessive hose pressure may cause water seepage and contamination of wheel bearings, front forks, brakes and transmission seals. Many expensive repair bills have resulted from improper high pressure detergent applications such as those available in coin-operated car washers.

  1. After the majority of the dirt has been hosed off, wash all surfaces with warm water and a mild detergent. Use an old toothbrush to clean hard-to-reach places.
  2. Rinse the machine off immediately with clean water, and dry all surfaces with a soft towel or cloth.
  3. Immediately after washing, remove excess water from the chain with a paper towel and lubricate the chain to prevent rust.
  4. Clean the seat with a vinyl upholstery cleaner to keep the cover pliable and glossy.
  5. Automotive wax may be applied to all painted or chromed surfaces. Avoid combination cleaner-waxes, as they may contain abrasives.
  6. After completing the above, start the engine and allow it to idle for several minutes.

NETTOYAGE ET RANGEMENT

NETTOYAGE

If your machine is to be stored for 60 days or more, some preventive measures must be taken to avoid deterioration. After cleaning the machine thoroughly, prepare it for storage as follows:

  1. Drain the fuel tank, fuel lines, and the carburetor float bowl.
  2. Remove the spark plug, pour a tablespoon of SAE 10W-30 motor oil in the spark plug hole, and reinstall the plug. With the engine stop switch pushed in, kick the engine over several times to coat the cylinder walls with oil.
  3. Remove the drive chain, clean it thoroughly with solvent, and lubricate it. Reinstall the chain or store it in a plastic bag tied to the frame.
  4. Lubricate all control cables.
  5. Block the frame up to raise the wheels off the ground.
  6. Tie a plastic bag over the exhaust pipe outlet to prevent moisture from entering.
  7. If the machine is to be stored in a humid or salt-air environment, coat all exposed metal surfaces with a film of light oil. Do not apply oil to rubber parts or the seat cover.

NOTE:

Make any necessary repairs before the machine is stored.

RANGEMENT

Model name:WR250FP (USA)WR250F (EUROPE)WR250F(P) (CDN, AUS, NZ, ZA)
Model code number:5PH5 (USA)5PH6 (EUROPE)5PH8 (CDN, AUS, NZ, ZA)
Dimensions:
Overall length2,165 mm (85.2 in)
Overall width827 mm (32.6 in)
Overall height1,303 mm (51.3 in)
Seat height998 mm (39.3 in)
Wheelbase1,475 mm (58.1 in)
Minimum ground clearance382 mm (15.0 in)
Basic weight:
With oil and full fuel tank110.0 kg (242.5 lb)
Engine:
Engine typeLiquid cooled 4-stroke, DOHC
Cylinder arrangementSingle cylinder, forward inclined
Displacement249 cm ^3 (8.76 Imp oz, 8.42 US oz)
Bore × stroke77.0 × 53.6 mm (3.03 × 2.11 in)
Compression ratio12.5 : 1
Starting systemKickstarter
Lubrication system:Dry sump
Oil type or grade:
Engine oil(For USA and CDN)At 5 °C (40 °F) or higherA Yamalube 4 (20W-40) or SAE 20W-40 typeSH motor oil(Non-Friction modified)At 15 °C (60 °F) or lowerB Yamalube 4 (10W-30) or SAE 10W-30 typeSH motor oil(Non-Friction modified)and/orYamalube 4-R (15W-50)(Non-Friction modified)
YAMAHA WR250FP - RANGEMENT - 1
YAMAHA WR250FP - RANGEMENT - 2Oil capacity:(Except for USA and CDN)API “SH” or higher grade
Engine oil
Periodic oil change1.5 L (1.32 Imp qt, 1.59 US qt)
With oil filter replacement1.6 L (1.41 Imp qt, 1.69 US qt)
Total amount1.7 L (1.50 Imp qt, 1.80 US qt)
Coolant capacity (including all routes):1.3 L (1.14 Imp qt, 1.37 US qt)
Air filter:Wet type element
Fuel:
TypePremium unleaded gasoline only with a research octane number of 95 or higher.(Except for ZA)
Premium gasoline (For ZA)
Tank capacity12 L (2.64 Imp gal, 3.17 US gal)(For USA and CDN)
8.0 L (1.76 Imp gal, 2.11 US gal)(Except for USA and CDN)
Reserve1.6 L (0.35 Imp gal, 0.42 US gal)(For USA and CDN)
1.4 L (0.31 Imp gal, 0.37 US gal)(Except for USA and CDN)
Carburetor:
TypeFCR-MX37
ManufacturerKEIHIN
Spark plug:
Type/manufacturerCR8E/NGK
U24ESR-N/DENSO
Gap0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
Clutch type:Wet, multiple-disc
Transmission:
Primary reduction systemGear
Primary reduction ratio57/17 (3.353)
Secondary reduction systemChain drive
Secondary reduction ratio52/13 (4.000)
Transmission typeConstant mesh, 5-speed
OperationLeft foot operation
Gear ratio: 1st31/13 (2.385)
2nd28/16 (1.750)
3rd28/21 (1.333)
4th25/24 (1.042)
5th22/27 (0.815)
Chassis:
Frame typeSemi double cradle
Caster angle27.1°
Trail117.4 mm (4.62 in)
Tire:TypeSize (front)Size (rear)Tire pressure (front and rear)With tube80/100-21 51M (For USA, CDN and ZA)90/90-21 54R (For EUROPE, AUS and NZ)100/100-18 59M (For USA, CDN and ZA)130/90-18 69R (For EUROPE, AUS and NZ)100 kPa ( 1.0 kgf/cm^2 , 15 psi)
Brake:Front brake typeOperationRear brake typeOperationSingle disc brakeRight hand operationSingle disc brakeRight foot operation
Suspension:Front suspensionRear suspensionTelescopic forkSwingarm (link type monocross suspension)
Shock absorber:Front shock absorberRear shock absorberCoil spring/oil damperCoil spring/gas, oil damper
Wheel travel:Front wheel travelRear wheel travel300 mm (11.8 in)315 mm (12.4 in)
Electrical:Ignition systemCDI magneto
Headlight type:Quartz bulb (halogen)
Bulb wattage × quantity:HeadlightTaillight12 V 60/55 W × 112 V 21/5 W × 1

MAINTENANCE SPECIFICATIONS

ENGINE

ItemStandardLimit
Cylinder head:Warp limitYAMAHA WR250FP - ENGINE - 1----0.05 mm(0.002 in)
Cylinder:Bore sizeOut of round limit77.00 ~ 77.01 mm(3.0315 ~ 3.0319 in)--------0.05 mm(0.002 in)
Camshaft:Drive methodCamshaft cap inside diameterCamshaft outside diameterShaft-to-cap clearanceCam dimensionsYAMAHA WR250FP - ENGINE - 2Chain drive (Left)22.000 ~ 22.021 mm(0.8661 ~ 0.8670 in)21.967 ~ 21.980 mm(0.8648 ~ 0.8654 in)0.020 ~ 0.054 mm(0.0008 ~ 0.0021 in)--------0.08 mm(0.003 in)
Intake“A”30.296 ~ 30.346 mm(1.1923 ~ 1.1947 in)30.196 mm(1.1888 in)
“B”22.45 ~ 22.55 mm(0.8839 ~ 0.8878 in)22.35 mm(0.8799 in)
Exhaust“A”30.399 ~ 30.499 mm(1.1968 ~ 1.2007 in)30.299 mm(1.1929 in)
“B”22.45 ~ 22.55 mm(0.8839 ~ 0.8878 in)22.35 mm(0.8799 in)
Camshaft runout limitYAMAHA WR250FP - ENGINE - 3----0.03 mm(0.0012 in)
Timing chain:
Timing chain type/No. of links92RH2010-114M/114----
Timing chain adjustment methodAutomatic----
Valve, valve seat, valve guide:
Valve clearance (cold)IN0.10 ~ 0.15 mm(0.0039 ~ 0.0059 in)----
EX0.17 ~ 0.22 mm(0.0067 ~ 0.0087 in)----
Valve dimensions:
YAMAHA WR250FP - ENGINE - 4YAMAHA WR250FP - ENGINE - 5YAMAHA WR250FP - ENGINE - 6YAMAHA WR250FP - ENGINE - 7
Head DiameterFace WidthSeat WidthMargin Thickness
“A” head diameterIN22.9 ~ 23.1 mm(0.9016 ~ 0.9094 in)----
EX24.4 ~ 24.6 mm(0.9606 ~ 0.9685 in)----
“B” face widthIN2.26 mm (0.089 in)----
EX2.26 mm (0.089 in)----
“C” seat widthIN0.9 ~ 1.1 mm(0.0354 ~ 0.0433 in)1.6 mm(0.0630 in)
EX0.9 ~ 1.1 mm(0.0354 ~ 0.0433 in)1.6 mm(0.0630 in)
“D” margin thicknessIN0.8 mm (0.0315 in)----
EX0.7 mm (0.0276 in)----
Stem outside diameterIN3.975 ~ 3.990 mm(0.1565 ~ 0.1571 in)3.945 mm(0.1553 in)
EX4.460 ~ 4.475 mm(0.1756 ~ 0.1762 in)4.430 mm(0.1744 in)
Guide inside diameterIN4.000 ~ 4.012 mm(0.1575 ~ 0.1580 in)4.050 mm(0.1594 in)
EX4.500 ~ 4.512 mm(0.1772 ~ 0.1776 in)4.550 mm(0.1791 in)
Stem-to-guide clearanceIN0.010 ~ 0.037 mm(0.0004 ~ 0.0015 in)0.08 mm(0.003 in)
EX0.025 ~ 0.052 mm(0.0010 ~ 0.0020 in)0.10 mm(0.004 in)
ItemStandardLimit
Stem runout limit----0.01 mm(0.0004 in)
YAMAHA WR250FP - ENGINE - 8
Valve seat widthIN0.9 ~ 1.1 mm(0.0354 ~ 0.0433 in)1.6 mm(0.0630 in)
EX0.9 ~ 1.1 mm(0.0354 ~ 0.0433 in)1.6 mm(0.0630 in)
Valve spring:
Free lengthIN37.81 mm (1.49 in)35.9 mm(1.41 in)
EX37.54 mm (1.48 in)35.7 mm(1.41 in)
Set length (valve closed)IN29.13 mm (1.15 in)----
EX29.30 mm (1.15 in)----
Compressed pressure(installed)IN99 ~ 114 N(10.1 ~ 11.6 kg, 22.27 ~ 25.57 lb)----
EX126 ~ 144 N(12.9 ~ 14.7 kg, 28.44 ~ 32.41 lb)----
Tilt limit *IN----2.5°/ 1.7 mm(2.5°/0.067 in)
EX----2.5°/1.6 mm(2.5°/0.063 in)
YAMAHA WR250FP - ENGINE - 9
Direction of winding(top view)INClockwise----
EXClockwise----
Piston:
Piston to cylinder clearance0.040 ~ 0.065 mm(0.0016 ~ 0.0026 in)0.1 mm(0.004 in)
Piston size “D”76.955 ~ 76.970 mm(3.0297 ~ 3.0303 in)----
YAMAHA WR250FP - ENGINE - 10
Measuring point “H”8 mm (0.31 in)----
Piston off-set0.5 mm (0.020 in)/IN-side----
ItemStandardLimit
Piston pin bore inside diameter16.002 ~ 16.013 mm(0.6300 ~ 0.6304 in)16.043 mm(0.6316 in)
Piston pin outside diameter15.991 ~ 16.000 mm(0.6296 ~ 0.6299 in)15.971 mm(0.6288 in)
Piston rings:Top ring:YAMAHA WR250FP - ENGINE - 11
TypeBarrel----
Dimensions (B × T)0.90 × 2.75 mm (0.04 × 0.11 in)----
End gap (installed)0.15 ~ 0.25 mm(0.006 ~ 0.010 in)0.50 mm(0.020 in)
Side clearance (installed)0.030 ~ 0.065 mm(0.0012 ~ 0.0026 in)0.12 mm(0.005 in)
2nd ring:YAMAHA WR250FP - ENGINE - 12
TypeTaper----
Dimensions (B × T)0.80 × 2.75 mm (0.03 × 0.11 in)----
End gap (installed)0.30 ~ 0.45 mm(0.012 ~ 0.018 in)0.80 mm(0.031 in)
Side clearance0.020 ~ 0.055 mm(0.0008 ~ 0.0022 in)0.12 mm(0.005 in)
Oil ring:YAMAHA WR250FP - ENGINE - 13
Dimensions (B × T)1.50 × 2.25 mm (0.06 × 0.09 in)----
End gap (installed)0.10 ~ 0.40 mm(0.004 ~ 0.016 in)----
Crankshaft:Crank width “A”55.95 ~ 56.00 mm(2.203 ~ 2.205 in)----
Runout limit “C”YAMAHA WR250FP - ENGINE - 140.03 mm (0.0012 in)0.05 mm(0.002 in)
Big end side clearance “D”0.15 ~ 0.45 mm(0.0059 ~ 0.0177 in)0.50 mm(0.02 in)
Small end free play “F”0.4 ~ 1.0 mm(0.02 ~ 0.04 in)2.0 mm(0.08 in)
Decompression device:TypeManual----
Cable free play5 ~ 9 mm (0.20 ~ 0.35 in)----
ItemStandardLimit
Clutch:
Friction plate thickness2.9 ~ 3.1 mm(0.114 ~ 0.122 in)2.7 mm(0.106 in)
Quantity9----
Clutch plate thickness1.1 ~ 1.3 mm (0.043 ~ 0.051 in)----
Quantity8----
Warp limit----0.1 mm(0.004 in)
Clutch spring free length37.0 mm (1.46 in)36.0 mm(1.42 in)
Quantity5----
Clutch housing thrust clearance0.10 ~ 0.35 mm(0.0039 ~ 0.0138 in)----
Clutch housing radial clearance0.010 ~ 0.044 mm(0.0004 ~ 0.0017 in)----
Clutch release methodInner push, cam push----
Shifter:
Shifter typeCam drum and guide bar----
Guide bar bending limit----0.05 mm(0.002 in)
Kickstarter:TypeKick and ratchet type----
Carburetor:USAEUROPECDN, ZA,AUS, NZ
Type/manufacturerFCR-MX37/KEIHIN
I. D. mark5PH5 505PH6 605PH8 80
Main jet(M.J)#175#172#170
Main air jet(M.A.J)#200
Jet needle(J.N)OBELQ-3OBELN-4OBEKP-3
Cutaway(C.A)1.5
Pilot jet(P.J)#40
Pilot air jet(P.A.J)#75
Pilot outlet(P.O)ø0.9
Pilot screw (example)(P.S)211-1/8
Bypass(B.P)ø1.0
Valve seat size(V.S)ø3.8
Starter jet(G.S)#72
Leak jet(Acc.P)#60#90#105
Float height(F.H)8 mm (0.31 in)
Engine idle speed1,800 ~2,100 r/min
Intake vacuum26.7 ~ 32.0 kPa(200 ~ 240 mmHg,7.87 ~ 9.45 inHg)
ItemStandardLimit
Lubrication system:
Oil filter typeWire mesh type----
Oil pump typeTrochoid type----
Tip clearance0.12 mm or less(0.0047 in or less)0.20 mm(0.008 in)
Side clearance0.09 ~ 0.17 mm(0.0035 ~ 0.0067 in)0.24 mm(0.009 in)
Housing and rotor clearance0.03 ~ 0.10 mm(0.0012 ~ 0.0039 in)0.17 mm(0.0067 in)
Cooling:
Radiator core size
Width117.8 mm (4.6 in)----
Height220 mm (8.7 in)----
Thickness32 mm (1.26 in)----
Radiator cap opening pressure110 kPa (1.1 kg/cm ^2 , 15.6 psi)----
Radiator capacity (total)0.6 L (0.53 lmp qt, 0.63 US qt)----
Water pump
TypeSingle-suction centrifugal pump----
Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
Spark plugM10S × 1.01131.39.4
Camshaft capM6 × 1.010101.07.2
Cylinder head blind plug screwM12 × 1.01373.727
Cylinder head (stud bolt)M6 × 1.0270.75.1
(stud bolt)M8 × 1.251151.511
(bolt)M9 × 1.254383.827
(nut)M6 × 1.02101.07.2
Cylinder head coverM6 × 1.02101.07.2
Oil pressure check boltM6 × 1.01101.07.2
CylinderM6 × 1.01101.07.2
Balancer weightM6 × 1.02101.07.2
Balancer shaft driven gearM14 × 1.01505.036
Timing chain guide (intake side)M6 × 1.02101.07.2
Decompression shaftM6 × 1.0170.75.1
Decompression cable guideM6 × 1.01101.07.2
Timing chain tensionerM6 × 1.02101.07.2
Timing chain tensioner cap boltM6 × 1.0170.75.1
ImpellerM8 × 1.251141.410
Radiator hose clampM6 × 1.0820.21.4
Coolant drain boltM6 × 1.01101.07.2
Water pump housingM6 × 1.04101.07.2
RadiatorM6 × 1.06101.07.2
Radiator guardM6 × 1.02101.07.2
Radiator pipeM6 × 1.01101.07.2
Oil pump coverM4 × 0.7130.32.2
Oil pumpM6 × 1.03101.07.2
Oil filter element drain boltM6 × 1.01101.07.2
Oil filter element coverM6 × 1.02101.07.2
Oil strainerM6 × 1.02101.07.2
Oil delivery pipe 1 (M10)M10 × 1.251202.014
(M8)M8 × 1.252181.813
Oil delivery pipe 2M6 × 1.01101.07.2
Oil hoseM6 × 1.03101.07.2
Oil hose clamp220.21.4
Oil strainer and frameM18 × 1.51909.065
Carburetor joint clampM4 × 0.7230.32.2
Air filter joint clampM6 × 1.0130.32.2
Throttle cable coverM5 × 0.8140.42.9
Air filter jointM5 × 0.8250.53.6
Air filter joint and air filter caseM5 × 0.8510.10.7
Air filter elementM6 × 1.0120.21.4
Air filter case coverM6 × 1.0440.42.9
Exhaust pipe (nut)M8 × 1.251131.39.4
(bolt)M8 × 1.251242.417
Exhaust pipe protectorM6 × 1.03101.07.2

YAMAHA WR250FP - ENGINE - 15

YAMAHA WR250FP - ENGINE - 16

Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
SilencerM8 × 1.252353.525
Silencer clampM8 × 1.251202.014
Spark arrester (for USA)M6 × 1.03101.07.2
Silencer end pipe (for USA)M6 × 1.01101.07.2
CrankcaseM6 × 1.011121.28.7
Crankcase bearing stopperM6 × 1.011101.07.2
Crankcase bearing stopper (crankshaft)M6 × 1.04101.07.2
Left crankcase coverM6 × 1.08101.07.2
Right crankcase coverM6 × 1.08101.07.2
Clutch coverM6 × 1.07101.07.2
Crankcase oil drain boltM10 × 1.251202.014
Drive chain sprocket coverM6 × 1.0280.85.8
Kick shaft ratchet wheel guideM6 × 1.02121.28.7
Kickstarter crankM8 × 1.251333.324
Primary drive gearM18 × 1.01757.554
Clutch springM6 × 1.0580.85.8
Clutch bossM16 × 1.01606.043
Push lever shaftM6 × 1.01101.07.2
Drive sprocketM18 × 1.01757.554
Drive axle oil seal stopperM6 × 1.02101.07.2
SegmentM8 × 1.251303.022
Shift guideM6 × 1.02101.07.2
Stopper leverM6 × 1.01101.07.2

NOTE:
△- marked portion shall be checked for torque tightening after break-in or before each race.

CHASSIS

ItemStandardLimit
Steering system:Steering bearing typeTaper roller bearing----
Front suspension:USA, CDNEUROPEAUS, NZ, ZA
Front fork travel300 mm (11.8 in)
Fork spring free length460 mm (18.1 in)
Spring rate, STDK = 4.31 N/mm(0.44 kg/mm,24.6 lb/in)K = 4.12 N/mm(0.42 kg/mm,23.5 lb/in)K = 4.02 N/mm(0.41 kg/mm,23 lb/in)
Optional spring/spacerYes
Oil capacity568 cm3(20.0 lmp oz,19.2 US oz)578 cm3(20.3 lmp oz,19.5 US oz)568 cm3(20.0 lmp oz,19.2 US oz)
Oil level140 mm (5.51 in)130 mm (5.12 in)140 mm (5.51 in)
<Min.~Max.> (From top of outer tube with inner tube and damper rod fully compressed without spring.)80 ~ 150 mm(3.15 ~ 5.91 in)
Oil gradeSuspension oil“01”
Inner tube outer diameter46 mm (1.81 in)
Front fork top end5 mm (0.20 in)8 mm (0.31 in)10.5 mm (0.41 in)
Rear suspension:USA, CDNEUROPEAUS, NZ, ZA
Shock absorber travel132 mm (5.20 in)
Spring free length260 mm (10.24 in)
Fitting length244 mm (9.61 in)247 mm (9.72 in)243.5 mm (9.59 in)
<Min.~Max.>240.5 ~ 258.5 mm(9.47 ~ 10.18 in)
Spring rate, STDK = 49.0 N/mm(5.00 kg/mm,280.0 lb/in)K = 47.0 N/mm(4.80 kg/mm,268.8 lb/in)
Optional springYes
Enclosed gas pressure1,000 kPa(10 kg/cm2, 142 psi)
Swingarm:Swingarm free play limitEnd----1.0 mm(0.04 in)
ItemStandardLimit
Wheel:USA, CDN, ZAEUROPE, AUS, NZ
Front wheel typeSpoke wheel----
Rear wheel typeSpoke wheel----
Front rim size/material21 × 1.60/Aluminum----
Rear rim size/material18 × 1.85/Aluminum18 × 2.15/Aluminum----
Rim runout limit:
Radial--------2.0 mm(0.08 in)
Lateral--------2.0 mm(0.08 in)
Drive chain:
Type/manufacturerDID520VM/DAIDO----
Number of links113 links + joint----
Chain slack40 ~ 50 mm (1.6 ~ 2.0 in)----
Chain length (10 links)----150.1 mm(5.91 in)
Front disc brake:
Disc outside dia. × Thickness250 × 3.0 mm (9.84 × 0.12 in)250 × 2.5 mm(9.84 × 0.10 in)
Pad thickness4.4 mm (0.17 in)1.0 mm(0.04 in)
Master cylinder inside dia.11.0 mm (0.433 in)----
Caliper cylinder inside dia.27.0 mm (1.063 in) × 2----
Brake fluid typeDOT #4----
Rear disc brake:
Disc outside dia. × Thickness245 × 4.0 mm (9.65 × 0.16 in)245 × 3.5 mm(9.65 × 0.14 in)
Deflection limit----0.15 mm(0.006 in)
Pad thickness6.4 mm (0.25 in)1.0 mm(0.04 in)
Master cylinder inside dia.12.7 mm (0.500 in)----
Caliper cylinder inside dia.27.0 mm (1.063 in) × 1----
Brake fluid typeDOT #4----
Brake lever and brake pedal:
Brake lever position95 mm (3.74 in)----
Brake pedal height(vertical height below footrest top)5 mm (0.20 in)----
Clutch lever free play (lever end)8 ~ 13 mm (0.31 ~ 0.51 in)----
Throttle grip free play3 ~ 5 mm (0.12 ~ 0.20 in)----
Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
Upper bracket and outer tubeM8 × 1.254232.317
Lower bracket and outer tubeM8 × 1.254202.014
Upper bracket and steering stemM24 × 1.0114514.5105
Handlebar holder and upper bracketM8 × 1.254282.820
Steering stem and steering ring nutM28 × 1.01Refer to NOTE.
Front fork and front fork cap boltM48 × 1.02303.022
Front fork and base valveM30 × 1.02555.540
Front fork cap bolt and damper rodM12 × 1.252292.921
Front fork bleed screw and front fork cap boltM5 × 0.8210.10.7
Front fork and front fork protectorM6 × 1.06101.07.2
Meter cable holder and front fork protectorM5 × 0.8240.42.9
Front fork and brake hose guideM5 × 0.8240.42.9
Front fork and brake hose holderM6 × 1.02101.07.2
Front fork and brake hose cover (M8)M8 × 1.251161.611
(M6)M6 × 1.0170.75.1
Throttle grip capM5 × 0.8240.42.9
Front brake master cylinderM6 × 1.0290.96.5
Brake lever mounting boltM6 × 1.0160.64.3
Brake lever mounting nutM6 × 1.0160.64.3
Brake lever position locknutM6 × 1.0150.53.6
Front brake hose guideM5 × 0.8240.42.9
Clutch lever holderM5 × 0.8240.42.9
Clutch lever mounting boltM6 × 1.0120.21.4
Decompression lever holderM5 × 0.8240.42.9
Light switchM4 × 0.7220.21.4
Front brake master cylinder capM4 × 0.7220.21.4
Front brake hose union boltM10 × 1.252303.022
Front brake caliperM8 × 1.252232.317
Pad pin plugM10 × 1.0230.32.2
Front brake caliper and pad pinM10 × 1.01181.813
Rear brake caliper and pad pinM10 × 1.01181.813
Brake caliper and bleed screwM8 × 1.25260.64.3
Front wheel axle and axle nutM16 × 1.5110510.575
Front wheel axle holderM8 × 1.254232.317
Front brake discM6 × 1.06121.28.7

NOTE:
1. First, tighten the steering nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the steering nut wrench, then loosen the steering nut one turn.
2. Retighten the steering nut 7 Nm (0.7 m • kg, 5.1 ft • lb).

Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
Rear brake discM6 × 1.06141.410
Brake pedalM8 × 1.251262.619
Rear brake master cylinderM6 × 1.02101.07.2
Rear brake reservoir tankM6 × 1.01101.07.2
Rear brake reservoir tank capM4 × 0.7220.21.4
Rear brake hose union boltM10 × 1.252303.02.2
Rear wheel axle and axle nutM20 × 1.5112512.590
Nipple (spoke)7230.32.2
Rear wheel sprocketM8 × 1.256424.230
Rear brake disc coverM6 × 1.0270.75.1
Rear brake caliper protectorM6 × 1.0270.75.1
Engine mounting:
Engine and engine bracket (front)M10 × 1.251696.950
Engine and frame (lower)M10 × 1.251696.950
Engine bracket and frameM8 × 1.256343.424
Engine and engine bracket (upper)M10 × 1.251555.540
Lower engine guardM6 × 1.03101.07.2
Left engine guardM8 × 1.252232.317
Right engine guardM8 × 1.252101.07.2
Pivot shaft and nutM16 × 1.51858.561
Relay arm and swingarmM14 × 1.51808.058
Relay arm and connecting rodM14 × 1.51808.058
Connecting rod and frameM14 × 1.51808.058
Rear shock absorber and frameM10 × 1.251565.640
Rear shock absorber and relay armM10 × 1.251535.338
Rear frameM8 × 1.253292.921
Swingarm and brake hose holderM5 × 0.8410.10.7
Swingarm and patchM4 × 0.7420.21.4
Upper drive chain tensionerM8 × 1.251191.913
Lower drive chain tensionerM8 × 1.251202.014
Drive chain caseM6 × 1.0370.75.1
Seal guard and swingarmM5 × 0.8460.64.3
Fuel tankM6 × 1.02101.07.2
Fuel cockM6 × 1.0270.75.1
Seat set bracket and fuel tankM6 × 1.0170.75.1
Hooking screw (fitting band) and fuel tankM6 × 1.0170.75.1
Radiator coverM6 × 1.0640.42.9
Front fenderM6 × 1.0470.75.1
Rear fender and air filter caseM6 × 1.0270.75.1
Rear fender and frame (right)M6 × 1.01101.07.2
Side coverM6 × 1.0270.75.1
SeatM8 × 1.252232.317
Headlight stay (lower) and lower bracketM8 × 1.25270.75.1
Headlight (left and right)M6 × 1.02101.07.2
Headlight (lower)M6 × 1.0170.75.1
TaillightM6 × 1.0340.42.9
Taillight lead clamp and rear fenderM4 × 1.59210.10.7
Coolant reservoir (front)M6 × 1.0170.75.1
Coolant reservoir (rear)M6 × 1.01111.18.0
Sidestand bracket and frameM10 × 1.252666.648
SidestandM10 × 1.251646.446

NOTE:

△ - marked portion shall be checked for torque tightening after break-in or before each race.

EC212300

ELECTRICAL

ItemStandardLimit
Ignition system:
Advancer typeElectrical----
CDI:
Magneto-model (stator)/manufacturer5NG-50/YAMAHA----
Charging coil 1 resistance (color)640 ~ 960 Ω at 20 °C (68 °F)(Green – Brown)----
Charging coil 2 resistance (color)464 ~ 696 Ω at 20 °C (68 °F)(Green – Pink)----
Lighting coil resistance (color)0.16 ~ 0.24 Ω at 20 °C (68 °F)(Black – Yellow)----
Pickup coil resistance (color)248 ~ 372 Ω at 20 °C (68 °F)(White – Red)----
CDI unit-model/manufacturer5PH-50/YAMAHA(For USA)5PH-60/YAMAHA(For EUROPE)5PH-80/YAMAHA(For CDN, AUS, NZ and ZA)----
Ignition coil:
Model/manufacturer4SR-00/YAMAHA----
Minimum spark gap6 mm (0.24 in)----
Primary coil resistance0.20 ~ 0.30 Ω at 20 °C (68 °F)----
Secondary coil resistance9.5 ~ 14.3 kΩ at 20 °C (68 °F)----
Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
StatorM6 × 1.03101.07.2
RotorM10 × 1.251484.835
Neutral switchM5 × 0.8240.42.9
Ignition coilM6 × 1.0270.75.1

EC220001

GENERAL TORQUE SPECIFICATIONS

This chart specifies torque for standard fasteners with standard I.S.O. pitch threads. Torque specifications for special components or assemblies are included in the applicable sections of this book. To avoid warpage, tighten multi-fastener assemblies in a crisscross fashion, in progressive stages, until full torque is reached. Unless otherwise specified, torque specifications call for clean, dry threads. Components should be at room temperature.

A(Nut)B(Bolt)TORQUE SPECIFICATION
Nmm•kgft•lb
10 mm6 mm60.64.3
12 mm8 mm151.511
14 mm10 mm303.022
17 mm12 mm555.540
19 mm14 mm858.561
22 mm16 mm1301394

YAMAHA WR250FP - GENERAL TORQUE SPECIFICATIONS - 1

text_image A B

A: Distance between flats

B: Outside thread diameter

EC230000

DEFINITION OF UNITS

UnitReadDefinitionMeasure
mmcmmillimetercentimeter 10^-3 meter 10^-2 meterLengthLength
kgkilogram 10^3 gramWeight
NNewton 1kg × m/sec^2 Force
Nm m • kgNewton meterMeter kilogram N × m m × kg TorqueTorque
PaPascal N/m^2 Pressure
N/mmNewton per millimeterN/mmSpring rate
L cm^3 LiterCubic centimeter——Volume or capacityVolume or capacity
r/minRevolution per minuteEngine speed

CARACTERISTIQUES

CARACTERISTIQUES GENERALES

① Hose guide
② Brake hose
③ Voltage regulator
④ Light switch lead
⑤ Fuel tank breather hose
⑥ Engine stop switch lead
⑦ Clamp
⑧ Oil tank breather hose
⑨ Sub-wire harness
⑩ Taillight lead
⑪ Throttle position sensor lead
⑫ Neutral switch lead
⑬ Oil hose
⑭ Cylinder head breather hose
⑮ CDI magneto lead
⑯ Clutch cable
⑰ Cable guide
⑱ Carburetor breather hose

⑲ Carburetor overflow hose
⑳ Coolant reservoir breather hose
②1 Decompression cable
② Ground lead
②3 Ignition coil lead
⑳ CDI unit lead
⑲ Voltage regulator lead
A Pass the fuel tank breather hose behind handlebar, then insert it into the steering stem hole.
B Pass the decompression cable, engine stop switch lead and light switch lead under where the oil hose is attached.
C Pass the voltage regulator lead, engine stop switch lead and light switch lead over the radiator hose.

D Fasten the engine stop switch lead, light switch lead and ignition coil lead of the sub-wire harness.
E Fasten the sub-wire harness and engine stop switch lead.
F Pass the cylinder head breather hose along the right side of the oil tank breather hose.
G Fasten the sub-wire harness and light switch lead in front of the upper engine brackets.
H Fasten the sub-wire harness.
☐ Pass the sub-wire harness between the upper engine brackets.
☐ Fasten the sub-wire harness.
K Fasten the throttle position sensor lead.

YAMAHA WR250FP - CARACTERISTIQUES GENERALES - 1

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, U, V, W, X, Y, AB)

CHEMINEMENT DES CABLES

① Guide de durit

② Durit de frein

Make sure that the throttle position sensor lead coupler does not go outside the chassis.
M Pass the carburetor breather hoses and overflow hose between the connecting rod and cross tube (frame).
N Fasten the neutral switch lead on the oil hose with a plastic locking tie and cut off the tie end.
☐ Pass the cylinder head breather hose through the hose guide.
☐ Pass the clutch cable through the cable guide.
☐ Fasten the neutral switch lead and CDI magneto lead.

R Pass the clutch cable along the inner side of the cylinder head breather hose.
S Pass the cylinder head breather hose along the inner side of the radiator hose.
T Pass the clutch cable in front of the radiator mounting boss.
☐ Fit the brake hose into the guides on the protector.
☑ Pass the neutral switch lead and CDI magneto lead through the cable guide.
W Fasten the ground lead together with the ignition coil lead.
☒ Do not allow the light switch lead to slacken between the two clamps.

Y Pass the decompression cable along the right side of the cylinder head breather hose.
Z Pass the clutch cable through the cable guides.
A A Pass the carburetor breather hoses, overflow hose and coolant reservoir breather hose so that all there hoses do not contact the rear shock absorber.
A B Position each lead at the lower left of the main tube (frame).

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 1

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, U, V, W, X, Y, AB)

① Coolant reservoir breather hose
② Radiator breather hose
③ Ignition coil
④ CDI unit
⑤ CDI unit band
⑥ Throttle cable (return)
⑦ Throttle cable (pull)
⑧ Cable guide
⑨ CDI unit lead
⑩ Spark plug lead
⑪ CDI unit stay

A Fasten the coolant reservoir breather hose and carburetor breather hoses together.
B Pass the throttle cables along inner side of the spark plug lead.
C Pass the CDI unit lead between the radiator hose and radiator mounting boss.
D Pass the throttle cables through the cable guides.
E Insert the CDI unit band over the CDI unit stay (frame) as far as possible.

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 2

natural_image Technical line drawing of a mechanical device with labeled components (no text or symbols present)

A

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 3

text_image ④ ⑤ E ⑪ D

B

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 4

text_image YAMAHA

① Coolant reservoir hose
② Coolant reservoir breather hose
③ Clamp
④ Taillight lead
⑤ Hose guide

A Fasten the coolant reservoir hose and coolant reservoir breather hose.
B Do not allow the taillight lead to slacken.
C Pass the coolant reservoir hose and coolant reservoir breather hose through the hose guide.

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 5

text_image Technical diagram of a vehicle interior with labeled components including parts A, B, and numbered parts 1 to 4.

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 6

text_image ⑤ C ② ①

① Brake hose
② Brake hose holder
③ Brake master cylinder

A Install the brake hose to the brake caliper with the paint on the pipe facing the brake caliper and with the pipe contacting the brake caliper projection.
B Pass the brake hose into the brake hose holders.
C If the brake hose contacts the spring (rear shock absorber), correct its twist.
D Install the brake hose so that its pipe portion directs as shown and lightly touches the projection on the brake master cylinder.

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 7

text_image A ① ② B ③ D C

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 8

text_image Technical diagram of a mechanical assembly with labeled parts A and numbered components

① Throttle cable
② Light switch
③ Light switch lead
④ Clamp
⑤ Decompression cable
⑥ Clutch cable
⑦ Hose guide
⑧ Trip meter
⑨ Brake hose
⑩ Engine stop switch lead

A Fasten the engine stop switch lead to the handlebar with the plastic band.
B Pass the throttle cables between the upper bracket and trip meter.
☐ Pass the light switch leads behind the engine stop switch lead, then pass the headlight lead (of the light switch leads) in front of the head pipe.
D Install the trip meter cable so that its bent portion faces the chassis rear.
E Install the brake hose so that it contacts the master cylinder projection and that its bent portion faces downward.

YAMAHA WR250FP - CHEMINEMENT DES CABLES - 9

text_image Technical schematic diagram of a mechanical device with numbered components and dimensional annotations including angles and diameters.

① Câble des gaz

The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind that such factors as weather, terrain, geographical location, and individual usage will alter the required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in maintaining and lubricating your machine, consult your Yamaha dealer.

* marked : For USA

ItemAfter break-inEvery raceEvery third race or 500 km (300 mi)Every fifth race or 1,000 km (600 mi)As requiredRemarks
ENGINE OILReplaceInspect
OIL FILTER ELEMENT, OIL STRAINER Clean
VALVESCheck the valve clearances.InspectReplaceThe engine must be cold.Check the valve seats and valve stems for wear.
VALVE SPRINGSInspectReplaceCheck the free length and the tilt.
VALVE LIFTERSInspectReplaceCheck for scratches and wear.
CAMSHAFTSInspectReplaceInspect the camshaft surface.
TIMING CHAIN SPROCKETS, TIMING CHAINInspectReplaceCheck for wear on the teeth and for damage.
PISTONInspectCleanReplaceInspect crackRemove carbon
PISTON RINGInspectReplace●●●●Check ring end gap
PISTON PINInspectReplace
CYLINDER HEADInspect and cleanRemove carbonChange gasket
CYLINDERInspect and cleanReplaceInspect score marksInspect wear
CLUTCHInspect and adjustReplaceInspect housing, friction plate, clutch plate and spring
TRANSMISSIONInspectReplace bearing●●
SHIFT FORK, SHIFT CAM, GUIDE BAR InspectInspect wear
ROTOR NUT Retighten
EXHAUST PIPE, SILENCER, PRO-TECTOR Inspect and retighten Clean Replace* Whichever comes first
*SPARK ARRESTER Clean(Every six months) ●
CRANK Inspect and clean
CARBURETOR Inspect, adjust and cleanWhen using a high-pres-sure washer, make sure that water does not enter the accelerator pump.
SPARK PLUG Inspect and clean Replace
DRIVE CHAIN Lubricate, slack, alignment ReplaceUse chain lube Chain slack: 40 ~ 50 mm (1.6 ~ 2.0 in)
COOLING SYSTEM Check coolant level and leakage Check radiator cap operation Replace coolant Inspect hoses●●Every two years
OUTSIDE NUTS AND BOLTS RetightenRefer to “STARTING AND BREAK-IN” section in the CHAPTER 1.
AIR FILTER Clean and lubricate ReplaceUse foam air-filter oil
FRAME Clean and inspect
FUEL TANK, COCK Clean and inspect
BRAKES Adjust lever position and pedal height Lubricate pivot point Check brake disc surface Check fluid level and leakage Retighten brake disc bolts, caliper bolts, master cylinder bolts and union bolts Replace pads Replace brake fluid●●●●●●●●●●●●●●●Every one year
FRONT FORKS Inspect and adjust Replace oil Replace oil seal●●Suspension oil “01”
ItemAfter break-inEvery raceEvery third race or 500 km (300 mi)Every fifth race or 1,000 km (600 mi)As re-quiredRemarks
FRONT FORK OIL SEAL AND DUST SEAL
Clean and lubeLithium base grease
REAR SHOCK ABSORBER(After rain ride)
Inspect and adjustMolybdenum disulfide grease
Lube
Retighten
CHAIN GUARD AND ROLLERS
Inspect
SWINGARMMolybdenum disulfide grease
Inspect, lube and retighten
RELAY ARM, CONNECTING RODMolybdenum disulfide grease
Inspect, lube and retighten
STEERING HEAD
Inspect free play and retightenLithium base grease
Clean and lube
Replace bearing
TIRE, WHEELS
Inspect air pressure, wheel run-out, tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
LubricateLithium base grease
THROTTLE, CONTROL CABLE
Check routing and connectionYamaha cable lube or SAE 10W-30 motor oil
Lubricate
Inspect and clean (throttle cable)Inspect dirt and wear on the throttle cable on the carburetor side.

CONTROLES ET REGLAGES COURANTS

PROGRAMME D'ENTRETIEN

Before riding for break-in operation, practice or a race, make sure the machine is in good operating condition.

Before using this machine, check the following points.

GENERAL INSPECTION AND MAINTENANCE

ItemRoutinePage
CoolantCheck that coolant is filled up to the radiator cap. Check that the coolant level is correct in the coolant reservoir. Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the fuel line for leakage.P.1-14
Engine oilCheck that the oil level is correct. Check the crankcase and frame oil line for leakage.P.3-14 ~ 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the clutch operates smoothly.P.3-9
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
BrakesCheck the play of front brake and effect of front and rear brake.P.3-26 ~ 32
Drive chainCheck drive chain slack and alignment. Check that the drive chain is lubricated properly.P.3-33 ~ 35
WheelsCheck for excessive wear and tire pressure. Check for loose spokes and have no excessive play.P.3-43 ~ 44
SteeringCheck that the handlebar can be turned smoothly and have no excessive play.P.3-44 ~ 45
Front forks and rear shock absorberCheck that they operate smoothly and there is no oil leakage.P.3-35 ~ 42
Cables (wires)Check that the clutch and throttle cables move smoothly. Check that they are not caught when the handlebars are turned or when the front forks travel up and down.
Exhaust pipeCheck that the exhaust pipe is tightly mounted and has no cracks.P.4-2
Rear wheel sprocketCheck that the rear wheel sprocket tightening bolt is not loose.P.3-33
LubricationCheck for smooth operation. Lubricate if necessary.P.3-46
Bolts and nutsCheck the chassis and engine for loose bolts and nuts.P.1-18
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are connected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course and weather or by taking into account the results of test runs before racing? Are inspection and maintenance completely done?P.7-1 ~ 23

CONTROLE ET ENTRETIEN AVANT UTILISATION

text_image Technical diagram showing a mechanical assembly with labeled component ①

YAMAHA WR250FP - CONTROLE ET ENTRETIEN AVANT UTILISATION - 1

text_image COOLANT FULL LOW a b

EC350000

ENGINE

EC351011

COOLANT LEVEL INSPECTION

WARNING

Do not remove the radiator cap ①, drain bolt and hoses when the engine and radiator are hot. Scalding hot fluid and steam may be blown out under pressure, which could cause serious injury.

When the engine has cooled, place a thick towel over the radiator cap, slowly rotate the cap counterclockwise to the detent. This procedure allows any residual pressure to escape. When the hissing sound has stopped, press down on the cap while turning counterclockwise and remove it.

CAUTION:

Hard water or salt water is harmful to the engine parts. You may use distilled water, if you can't get soft water.

  1. Place the machine on a level place, and hold it in an upright position.
  2. Inspect:
  3. Coolant level
    Coolant level should be between the maximum ⓐ and minimum ⓑ marks.
    Coolant level is below the “LOW” level line → Add soft water (tap water) up to the proper level.
  4. Start the engine and let it warm up for several minutes.
  5. Turn off the engine and check the coolant level again.

NOTE:

Before checking the coolant level, wait a few minutes until the coolant settles.

COOLANT REPLACEMENT

! WARNING

Do not remove the radiator cap when the engine is hot.

MOTEUR

CONTROLE DU NIVEAU DU LIQUIDE DE REFROIDISSEMENT

! AVERTISSEMENT

text_image COOLANT FULL LOW

YAMAHA WR250FP - ! AVERTISSEMENT - 1

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - ! AVERTISSEMENT - 2

text_image 1 : 1 ① ②

CAUTION:

Take care so that coolant does not splash on painted surfaces. If it splashes, wash it away with water.

  1. Place a container under the engine.
  2. Remove:

  3. Seat

  4. Left side cover

Refer to "SEAT FUEL TANK AND SIDE COVERS" section in the CHAPTER 4.

  1. Disconnect:

- Coolant reservoir hose ①

Drain the coolant completely.

  1. Connect:

- Coolant reservoir hose

  1. Remove:

  2. Remove:

  3. Coolant drain bolt ①

  4. Radiator cap

Drain the coolant completely.

  1. Clean:

- Cooling system

Thoroughly flush the cooling system with clean tap water.

  1. Install:

- Copper washer

New

- Coolant drain bolt

10 Nm (1.0 m · kg, 7.2 ft · lb)

  1. Fill:

  2. Radiator

  3. Engine

To specified level.

YAMAHA WR250FP - CAUTION: - 1

Recommended coolant: High quality ethylene glycol anti-freeze containing anti-corrosion for aluminum engine

Coolant ① and water

(soft water) ② mixing ratio: 50%/50%

Coolant capacity: 1.3 L (1.14 Imp qt, 1.37 US qt)

ATTENTION:

  • Do not mix more than one type of ethylene glycol antifreeze containing corrosion inhibitors for aluminum engine.
  • Do not use water containing impurities or oil.

Handling notes of coolant:

The coolant is harmful so it should be handled with special care.

WARNING

  • When coolant splashes to your eye. Thoroughly wash your eye with water and see your doctor.
  • When coolant splashes to your clothes. Quickly wash it away with water and then with soap.
  • When coolant is swallowed. Quickly make him vomit and take him to a doctor.

YAMAHA WR250FP - WARNING - 1

text_image COOLANT FULL LOW a
  1. Install:

- Radiator cap

  1. Fill:

- Coolant reservoir Midway ⓐ between maximum and minimum marks on the tank.

  1. Install:
  2. Coolant reservoir cap
  3. Start the engine and let it warm up for several minutes.
  4. Turn off the engine and inspect the coolant level. Refer to “COOLANT LEVEL INSPECTION” section.

NOTE:

Before checking the coolant level wait a few minutes until the coolant settles.

YAMAHA WR250FP - NOTE: - 1

text_image ① ② ③ I4110101

EC355000

RADIATOR CAP INSPECTION

  1. Inspect:

  2. Seal (radiator cap) ①

  3. Valve and valve seat ② Crack/damage → Replace.
    Exist fur deposits ③ → Clean or replace.

CONTROLE DU BOUCHON DU RADIATEUR KÜHLFLÜSSIGKEITSTAND KONTROLLIEREN CONTROLLO TAPPO DEL RADIATORE

ATTENTION:

- Radiator cap tester ① and adapter ②

YAMAHA WR250FP - ATTENTION: - 1

Radiator cap tester: YU-24460-01/90890-01325 Radiator cap tester adapter: YU-33984/90890-01352

NOTE:

Apply water on the radiator cap seal.

③ Radiator cap

  1. Apply the specified pressure.

YAMAHA WR250FP - NOTE: - 1

Radiator cap opening pressure: 110 kPa (1.1 kg/cm ^2 , 15.6 psi)

  1. Inspect:

- Pressure

Impossible to maintain the specified pressure for 10 seconds → Replace.

YAMAHA WR250FP - NOTE: - 2

text_image Technical diagram showing mechanical assembly with labeled parts, including pressure gauge and tubing connections

COOLING SYSTEM INSPECTION

  1. Inspect:

- Coolant level

  1. Attach:

- Radiator cap tester ① and adapter ②

YAMAHA WR250FP - COOLING SYSTEM INSPECTION - 1

Radiator cap tester: YU-24460-01/90890-01325

Radiator cap tester adapter: YU-33984/90890-01352

  1. Apply the specified pressure.

YAMAHA WR250FP - COOLING SYSTEM INSPECTION - 2

Standard pressure: 180 kPa (1.8 kg/cm ^2 , 25.6 psi)

CONTROLE DE LA PRESSION D'OUVERTURE DU BOUCHON DU RADIATEUR

  1. Attacher:
  • Do not apply pressure more than specified pressure.
  • Radiator should be filled fully.

YAMAHA WR250FP - CONTROLE DE LA PRESSION D'OUVERTURE DU BOUCHON DU RADIATEUR - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - CONTROLE DE LA PRESSION D'OUVERTURE DU BOUCHON DU RADIATEUR - 2

text_image a

YAMAHA WR250FP - CONTROLE DE LA PRESSION D'OUVERTURE DU BOUCHON DU RADIATEUR - 3

text_image Technical diagram showing mechanical assembly with numbered parts, likely illustrating engine or valve assembly steps.

4. Inspect:

  • Pressure
    Impossible to maintain the specified pressure for 10 seconds → Repair.
  • Radiator ①
  • Radiator hose joint ② Coolant leakage → Repair or replace.
  • Radiator hose ③ Swelling → Replace.

CLUTCH ADJUSTMENT

1. Check:

  • Clutch lever free play ⓐ
    Out of specification → Adjust.

YAMAHA WR250FP - Check: - 1

Clutch lever free play ⓐ: 8 \~ 13 mm (0.31 \~ 0.51 in)

2. Adjust:

- Clutch lever free play

Clutch lever free play adjustment steps:

  • Loosen the locknuts ①.
  • Adjust the free play by changing their tightening position.
  • Tighten the locknuts.

NOTE:

  • Make minute adjustment on the lever side using the adjuster ②.
  • After adjustment, check proper operation of clutch lever.

N.B.:

text_image Technical diagram showing a pipe connection with labeled component 'a' and directional arrows indicating flow or movement.

YAMAHA WR250FP - N.B.: - 1

text_image Technical diagram of a mechanical assembly with labeled parts, showing components like gears and springs.

YAMAHA WR250FP - N.B.: - 2

text_image Technical diagram of a mechanical assembly with numbered components for identification

THROTTLE CABLE ADJUSTMENT

1. Check:

- Throttle grip free play ⓐ Out of specification → Adjust.

YAMAHA WR250FP - Check: - 1

Throttle grip free play ⓐ: 3 \~ 5 mm (0.12 \~ 0.20 in)

2. Adjust:

- Throttle grip free play

Throttle grip free play adjustment steps:

- Remove the throttle cable cap ① and throttle cable cover ②.

NOTE:

  • Before adjusting the throttle cable free play, the engine idle speed should be adjusted.
  • When the motorcycle is accelerating, throttle cable #1 ③ is pulled and throttle cable #2 ④ is pushed.

1st step:

  • Loosen the locknuts ⑤ on throttle cable #2.
  • Adjust the free play by changing their tightening position.

2nd step:

  • Loosen the locknuts ⑥ on throttle cable #1.
  • Adjust the free play by changing their tightening position.
  • Tighten the locknuts.

WARNING

After adjusting, turn the handlebar to right and left and make sure that the engine idling does not run faster.

- Install the throttle cable cover and throttle cable cap.

YAMAHA WR250FP - WARNING - 1

Throttle cable cover: 4 Nm (0.4 m • kg, 2.9 ft • lb)

THROTTLE LUBRICATION/DECOMPRESSION ADJUSTMENT

INSP ADJ

YAMAHA WR250FP - INSP ADJ - 1

YAMAHA WR250FP - INSP ADJ - 2

text_image Technical diagram showing three labeled mechanical components in a vehicle, with numbered annotations indicating parts of each.

YAMAHA WR250FP - INSP ADJ - 3

text_image Technical diagram showing mechanical assembly with labeled parts a and B, likely illustrating a gear or cam mechanism.

YAMAHA WR250FP - INSP ADJ - 4

text_image Technical diagram showing mechanical components with numbered labels ① and ② indicating parts of a gear or pump assembly.

YAMAHA WR250FP - INSP ADJ - 5

text_image a

YAMAHA WR250FP - INSP ADJ - 6

text_image Technical diagram of a mechanical assembly with labeled components and directional arrow indicating rotation or movement.

THROTTLE LUBRICATION

1. Remove:

  • Cover (throttle cable cap) ①
  • Cover (grip cap) ②
  • Throttle grip cap ③

2. Apply:

- Lithium soap base grease On the throttle cable end ⓐ.

3. Install:

  • Throttle grip cap
  • Screw (throttle grip cap)

4 Nm (0.4 m · kg, 2.9 ft · lb)

  • Cover (grip cap)
  • Cover (throttle cable cap)

DECOMPRESSION ADJUSTMENT

1. Check:

- Decompression lever free play ⓐ Out of specification → Adjust.

Checking steps:

  • Remove the timing mark accessing screw ① and crankshaft end accessing screw ②.
  • Turn the crankshaft counterclockwise with a wrench.

NOTE:

Squeezing the decompression lever allows the crankshaft to be turned easily.

  • Align the T.D.C. mark ⓑ on the rotor with the align mark © on the crankcase cover when piston is at T.D.C. on compression stroke.
  • Check the free play.

YAMAHA WR250FP - NOTE: - 1

Free play ⓐ: 5 \~ 9 mm (0.20 \~ 0.35 in)

GRAISSAGE DE L'ACCELERATEUR

text_image Technical diagram of a mechanical device with labeled parts ① and ②, showing assembly or assembly details.

2. Adjust:

- Decompression lever free play

Adjustment steps:

  • Loosen the locknut ①.
  • Turn the adjuster ② in or out until the adjustment is suitable.
  • Tighten the locknut.

CAUTION:

After the adjustment, start the engine and make sure that the engine does not stop when the handlebar is turned fully both ways. If the decompression cable is too tense, the engine will stop by the decompression system.

AIR FILTER CLEANING

NOTE:

Proper air filter maintenance is the biggest key to preventing premature engine wear and damage.

CAUTION:

Never run the engine without the air filter element in place; this would allow dirt and dust to enter the engine and cause rapid wear and possible engine damage.

YAMAHA WR250FP - CAUTION: - 1

text_image Technical diagram of a car intake hood with numbered components and highlighted parts for assembly or maintenance.

1. Remove:

- Seat

2. Disconnect:

• Taillight lead connectors ①

3. Remove:

- Air filter case cover ②

YAMAHA WR250FP - Remove: - 1

text_image Technical diagram showing a vehicle interior with labeled parts, including a gear mechanism and a fan assembly.

4. Remove:

  • Fitting bolt ①
  • Washer ②
  • Air filter element ③
  • Air filter guide ④

2. Régler:

text_image Illustration showing three steps of a hand pouring liquid into a container, with arrows indicating the process.

5. Clean:

• Air filter element Clean them with solvent.

NOTE:

After cleaning, remove the remaining solvent by squeezing the element.

CAUTION:

  • Do not twist the element when squeezing the element.
  • Leaving too much of solvent in the element may result in poor starting.

6. Inspect:

- Air filter element Damage → Replace.

7. Apply:

- Foam-air-filter oil or engine oil to the element.

NOTE:

Squeeze out the excess oil. Element should be wet but not dripping.

8. Install:

- Air filter guide ①

NOTE:

Align the projection ⓐ on air filter guide with the hole ⓑ in air filter element.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical component with labeled parts (a, b, c, d) and directional arrows indicating assembly or motion.

YAMAHA WR250FP - NOTE: - 2

text_image a B

9. Apply:

- Lithium soap base grease On the matching surface ⓐ on air filter element.

5. Nettoyer:

text_image Technical diagram of a mechanical assembly with labeled parts (a, b, 1, 2) and numbered annotations.

10. Install:

  • Air filter element ①
  • Washer
  • Fitting bolt

YAMAHA WR250FP - Install: - 1

2 Nm (0.2 m · kg, 1.4 ft · lb)

NOTE:

Align the projection Ⓐ on filter guide with the hole ⓑ in air filter case.

ENGINE OIL LEVEL INSPECTION

  1. Start the engine, warm it up for several minutes, and then turn off the engine and wait for five minutes.
  2. Place the machine on a level place and hold it up on upright position by placing the suitable stand under the engine.

YAMAHA WR250FP - ENGINE OIL LEVEL INSPECTION - 1

natural_image Line drawing of a mechanical device with labeled component (no text or symbols present)

3. Remove:

- Oil tank cap ①

YAMAHA WR250FP - Remove: - 1

text_image Technical diagram showing a hand operating a tool on a mechanical assembly with labeled parts (a) and (b)

4. Inspect:

- Oil level

Oil level should be between maximum ① and minimum ② marks.

Oil level is low → Add oil to proper level.

NOTE:

When inspecting the oil level, do not screw the oil tank cap into the oil tank. Insert the gauge lightly.

CONTROLE DU NIVEAU D'HUILE MOTEUR MOTORÖLSTAND KONTROLLIEREN CONTROLLO DEL LIVELLO DELL'OLIO MOTORE

10. Monter:

Recommended oil: At 5 °C (40 °F) or higher A Yamalube 4 (20W-40) or SAE 20W-40 type SH motor oil (Non-Friction modified) At 15 °C (60 °F) or lower B Yamalube 4 (10W-30) or SAE 10W-30 type SH motor oil (Non-Friction modified) and/or Yamalube 4-R (15W-50) (Non-Friction modified)

CAUTION:

  • Do not add any chemical additives. Engine oil also lubricates the clutch and additives could cause clutch slippage.
  • Do not allow foreign material to enter the crankcase.

YAMAHA WR250FP - CAUTION: - 1

line | Temp. | Temperature (°C) | |---|---| | -10 | 10W-30 | | 0 | 10W-40 | | 30 | 15W-40 | | 68 | 20W-40 | | 86 | 20W-50 | | 104 | 50 | | 122 | 50 |

(Except for USA and CDN)

YAMAHA WR250FP - CAUTION: - 2

Recommended oil: Refer to the following chart for selection of oils which are suited to the atmospheric temperatures. Recommended engine oil classification:

API STANDARD: API "SH" or higher grade (Designed primarily for motor- cycles)

YAMAHA WR250FP - CAUTION: - 3

flowchart
graph TD
    A["API SERVICE SH/CD"] --> B["SAE 10W-30"]
    B --> C["ENERGY CONSERVING II"]
    C --> D["a"]
    C --> E["b"]

CAUTION:

  • Do not add any chemical additives or use oils with a grade of CD ⓐ or higher.
  • Do not use oils labeled “ENERGY CONSERVING II” ⓑ or higher. Engine oil also lubricates the clutch and additives could cause clutch slippage.
  • Do not allow foreign materials to enter the crankcase.

  • Install:

  • Oil tank cap

  • Start the engine and let it warm up for several minutes.
  • Turn off the engine and inspect the oil level once again.

NOTE: ____

Wait a few minutes until the oil settles before inspecting the oil level.

CONTROLE DU NIVEAU D'HUILE MOTEUR MOTORÖLSTAND KONTROLLIEREN CONTROLLO DEL LIVELLO DELL'OLIO MOTORE

ENGINE OIL REPLACEMENT

  1. Start the engine and warm it up for several minutes, and then turn off the engine and wait for five minute.
  2. Place the machine on a level place and hold it on upright position by placing the suitable stand under the engine.
  3. Place a suitable container under the engine.

YAMAHA WR250FP - ENGINE OIL REPLACEMENT - 1

text_image Technical diagram showing two mechanical assembly steps with labeled components

YAMAHA WR250FP - ENGINE OIL REPLACEMENT - 2

text_image Technical diagram showing mechanical assembly with numbered components, likely illustrating a gear or linkage mechanism.

YAMAHA WR250FP - ENGINE OIL REPLACEMENT - 3

text_image Technical diagram of a mechanical assembly with numbered components for identification

4. Remove:

  • Oil tank cap ①
  • Frame oil drain bolt ②
  • Crankcase oil drain bolt ③
  • Oil filter element drain bolt ④
    Drain the crankcase and oil tank (frame) of its oil.

5. Remove:

  • Lower engine bracket
  • Oil hose clamp ①
  • Bolt (oil hose) ②
  • Oil hose ③
  • Oil strainer (frame) ④

6. Inspect:

  • Oil strainer (frame)
    Clogged → Blow.

CHANGEMENT DE L'HUILE DE MOTEUR

text_image ① ③ New ③ New ② New ③

YAMAHA WR250FP - CHANGEMENT DE L'HUILE DE MOTEUR - 1

text_image New ① ② ③ ④ ⑤
  1. If the oil filter is to be replaced during this oil change, remove the following parts and reinstall them.

Replacement steps:

  • Remove the oil filter element cover ① and oil filter element ②.
  • Check the O-rings ③, if cracked or damaged, replace them with a new one.
  • Install the oil filter element and oil filter element cover.

YAMAHA WR250FP - Replacement steps: - 1

Oil filter element cover: 10 Nm (1.0 m • kg, 7.2 ft • lb)

8. Install:

  • Copper washer ① New
  • Oil strainer (frame) ②
    90 Nm (9.0 m · kg, 65 ft · lb)

- Oil hose ③

- Bolt (oil hose) ④

10 Nm (1.0 m · kg, 7.2 ft · lb)

- Oil hose clamp ⑤

2 Nm (0.2 m · kg, 1.4 ft · lb)

- Lower engine bracket

10 Nm (1.0 m · kg, 7.2 ft · lb)

9. Install:

• Copper washer New
- Oil filter element drain bolt
10 Nm (1.0 m · kg, 7.2 ft · lb)
- Crankcase oil drain bolt
20 Nm (2.0 m · kg, 14 ft · lb)
- Frame oil drain bolt
23 Nm (2.3 m · kg, 17 ft · lb)

10. Fill:

- Engine oil

YAMAHA WR250FP - Fill: - 1

Oil quantity:

Total amount:

1.7 L (1.50 Imp qt, 1.80 US qt)

Periodic oil change:

1.5 L (1.32 Imp qt, 1.59 US qt)

With oil filter replacement:

1.6 L (1.41 Imp qt, 1.69 US qt)

11. Check:

- Oil leakage

12. Install:

- Oil tank cap

13. Check:

- Engine oil level

(1,41 Imp qt, 1,69 US qt)

  1. Contrôler:

- Fuites d'huile

  1. Contrôler:

(1,41 Imp qt, 1,69 US qt)

  1. Controllare:

- Perdite d'olio

  1. Controllare:
natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

OIL PRESSURE INSPECTION

1. Check:

- Oil pressure

Checking steps:

  • Slightly loosen the oil pressure check bolt ①.
  • Start the engine and keep it idling until oil starts to seep from the oil pressure check bolt. If no oil comes out after one minute, turn the engine off so it will not seize.
  • Check oil passages and oil pump for damage or leakage.
  • Start the engine after solving the problem(s) and recheck the oil pressure.
  • Tighten the oil pressure check bolt.

YAMAHA WR250FP - Checking steps: - 1

Oil pressure check bolt: 10 Nm (1.0 m • kg, 7.2 ft • lb)

YAMAHA WR250FP - Checking steps: - 2

text_image Technical diagram showing engine component with numbered annotation indicating a specific part.

PILOT SCREW ADJUSTMENT

1. Adjust:

- Pilot screw ①

Adjustment steps:

NOTE:

To optimize the fuel flow at a smaller throttle opening, each machine's pilot screw has been individually set at the factory. Before adjusting the pilot screw, turn it in fully and count the number of turns. Record this number as the factory-set number of turns out.

  • Turn in the pilot screw until it is lightly seated.
  • Turn out the pilot screw by the factory-set number of turns.

YAMAHA WR250FP - NOTE: - 1

Pilot screw:

2 turns out

* 1 turn out

** 1-1/8 turns out

(example)

* For EUROPE
** For CDN, ZA, AUS and NZ

CONTROLE DE LA PRESSION D'HUILE

1. Contrôler:

- Pression d'huile

Etapes du contrôle:

text_image Technical diagram showing mechanical assembly with labeled parts (a, b) and directional arrows indicating motion or movement.

ENGINE IDLING SPEED ADJUSTMENT

  1. Start the engine and thoroughly warm it up.
  2. Attach:
  3. Inductive tachometer To spark plug lead.
  4. Adjust:
  5. Engine idling speed

Adjustment steps:

  • Adjust the pilot screw.
    Refer to "PILOT SCREW ADJUSTMENT" section.
  • Turn the throttle stop screw ① until the engine runs at the lowest possible speed.

To increase idle speed → Turn the throttle stop screw ① in ⓐ.

To decrease idle speed → Turn the throttle stop screw ① out ⑥.

YAMAHA WR250FP - To decrease idle speed → Turn the throttle stop screw ① out ⑥. - 1

Inductive tachometer: YU-8036-B

Engine tachometer: 90890-03113

YAMAHA WR250FP - To decrease idle speed → Turn the throttle stop screw ① out ⑥. - 2

Engine idling speed: 1,800 \~ 2,100 r/min

VALVE CLEARANCE INSPECTION AND ADJUSTMENT

NOTE:

  • The valve clearance should be adjusted when the engine is cool to the touch.
  • The piston must be at Top Dead Center (T.D.C.) on compression stroke to check or adjust the valve clearance.

1. Remove:

  • Seat
  • Fuel tank

Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4.

2. Drain:

- Coolant

Refer to "COOLANT REPLACEMENT" section.

  • Right radiator
    Refer to "RADIATOR" section in the CHAPTER 4.
  • Carburetor
    Refer to “CARBURETOR” section in the CHAPTER 4.
  • Spark plug
    • Upper engine bracket
  • Cylinder head cover
    Refer to "CAMSHAFTS" section in the CHAPTER 4.

YAMAHA WR250FP - Drain: - 1

text_image Technical diagram showing mechanical components with numbered annotations indicating parts of a gear or pump assembly.

4. Remove:

  • Timing mark accessing screw ①
  • Crankshaft end accessing screw ②
  • O-ring

5. Check:

- Valve clearance

Out of specification → Adjust.

YAMAHA WR250FP - Check: - 1

Valve clearance (cold):

Intake valve:

0.10 \~ 0.15 mm (0.0039 \~ 0.0059 in)

Exhaust valve:

0.17 \~ 0.22 mm (0.0067 \~ 0.0087 in)

CONTROLE ET REGLAGE DU JEU DE SOUPAPES VENTILSPIEL KONTROLLIEREN UND EINSTELLEN CONTROLLO E REGOLAZIONE DEL GIOCO DELLE VALVOLE

INSP ADJ

YAMAHA WR250FP - INSP ADJ - 1

3. Déposer:

text_image Technical diagram showing mechanical assembly with labeled parts (a, b) and directional arrow indicating rotation or movement.

YAMAHA WR250FP - Déposer: - 1

text_image C d E E

YAMAHA WR250FP - Déposer: - 2

text_image Technical diagram of a mechanical assembly with labeled components and directional arrows

YAMAHA WR250FP - Déposer: - 3

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

Checking steps:

- Turn the crankshaft counterclockwise with a wrench.

NOTE:

Squeezing the decompression lever allows the crankshaft to be turned easily.

- Align the T.D.C. mark ⓐ on the rotor with the align mark ⓑ on the crankcase cover when piston is at T.D.C. on compression stroke.

NOTE:

In order to be sure that the piston is at Top Dead Center, the punch mark © on the exhaust camshaft and the punch mark ⓐ on the intake camshaft must align with the cylinder head surface, as shown in the illustration.

- Measure the valve clearance Ⓔ using a feeler gauge ①.

NOTE:

Record the measured reading if the clearance is incorrect.

6. Adjust:

- Valve clearance

Adjustment steps:

- Remove the camshaft (intake and exhaust). Refer to “CAMSHAFTS” section in the CHAPTER 4.

text_image Technical diagram showing mechanical assembly with numbered components, likely illustrating a gear or valve mechanism.

YAMAHA WR250FP - Adjustment steps: - 1

text_image Technical diagram of an engine component with numbered parts labeled ⑤, ⑥, and ⑤

YAMAHA WR250FP - Adjustment steps: - 2

text_image EX IN

YAMAHA WR250FP - Adjustment steps: - 3

text_image a 175
  • Remove the decompression cable ①, guide ②, bolt ③ and decompression shaft ④.
  • Remove the valve lifters ⑤ and the pads ⑥.

NOTE:

  • Place a rag in the timing chain space to prevent pads from falling into the crank-case.
  • Identity each valve lifter and pad position very carefully so that they can be reinstalled in their original place.
  • Select the proper pad using the pad selecting table.
Pad rangePad Availability:25 increments
No. 120~No. 2401.20 mm~2.40 mmPads are available in0.05 mm increments

NOTE:

The thickness ⓐ of each pad is indicated in hundreths of millimeters on the pad upper surface.

- Round off the last digit of the installed pad number to the nearest increment.

Last digit of pad numberRounded value
0, 1or 20
4, 5 or 65
8 or 910

EXAMPLE:

Installed pad number = 148

Rounded off value = 150

NOTE:

Pads can only be selected in 0.05 mm increments.

text_image Technical diagram of a mechanical assembly with labeled parts and numbered annotations

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing mechanical assembly with numbered components and a labeled component 'E'

- Locate the rounded-off value and the measured valve clearance in the chart "PAD SELECTION TABLE". The field where these two coordinates intersect shows the new pad number to use.

NOTE: \_\_\_\_

Use the new pad number only as a guide when verifying the valve clearance adjustment.

- Install the new pads ⑦ and the valve lifters ⑧.

NOTE: \_\_\_\_

  • Apply the engine oil on the valve lifters.
  • Apply the molybdenum disulfied oil on the valve stem ends.
  • Valve lifter must turn smoothly when rotated with a finger.
  • Be careful to reinstall valve lifters and pads in their original place.
  • Install the decompression shaft ⑨, copper washer ⑩, bolt (decompression shaft) ⑪, guide ⑫, bolt (guide) ⑬ and decompression cable ⑭.

NOTE: \_\_\_\_

Apply the engine oil on the decompression shaft.

YAMAHA WR250FP - NOTE: \_\_\_\_ - 1

Bolt (decompression shaft):

7 Nm (0.7 m • kg, 5.1 ft • lb)

Bolt (guide):

10 Nm (1.0 m • kg, 7.2 ft • lb)

- Install the camshafts (exhaust and intake). Refer to “CAMSHAFTS” section in the CHAPTER 4.

  • Be sure the exhaust pipe and muffler are cool before cleaning the spark arrester.
  • Do not start the engine when cleaning the exhaust system.

YAMAHA WR250FP - NOTE: \_\_\_\_ - 2

text_image Technical diagram showing mechanical components with numbered labels ① and ②, likely illustrating a gear or pulley system.

YAMAHA WR250FP - NOTE: \_\_\_\_ - 3

natural_image Technical line drawing of a mechanical assembly with flanged components and a numbered label (1), no readable text or symbols present.

1. Remove:

- Bolt (spark arrester) ①

2. Remove:

- Spark arrester ① Pull the spark arrester out of the muffler.

3. Clean:

- Spark arrester Tap the spark arrester lightly, then use a wire brush to remove any carbon deposits.

4. Install:

- Spark arrester Insert the spark arrester into the muffler and align the bolt holes. - Bolt (spark arrester)

10 Nm (1.0 m · kg, 7.2 ft · lb)

Bleed the brake system if:

  • The system has been disassembled.
  • A brake hose has been loosened or removed.
    • The brake fluid is very low.
    • The brake operation is faulty.

A dangerous loss of braking performance may occur if the brake system is not properly bleed.

YAMAHA WR250FP - A dangerous loss of braking performance may occur if the brake system is not properly bleed. - 1

text_image A ① ②

YAMAHA WR250FP - A dangerous loss of braking performance may occur if the brake system is not properly bleed. - 2

text_image B ① ②
  1. Remove:

  2. Reservoir cap

  3. Diaphragm
  4. Protector (rear brake)

  5. Bleed:

- Brake fluid

A Front

B Rear

Air bleeding steps:

a. Add proper brake fluid to the reservoir.
b. Install the diaphragm. Be careful not to spill any fluid or allow the reservoir to overflow.
c. Connect the clear plastic tube ② tightly to the caliper bleed screw ①.
d. Place the other end of the tube into a container.
e. Slowly apply the brake lever or pedal several times.
f. Pull the lever in or push down on the pedal. Hold the lever or pedal in position.
g. Loosen the bleed screw and allow the lever or pedal to travel towards its limit.
h. Tighten the bleed screw when the lever or pedal limit has been reached; then release the lever or pedal.

YAMAHA WR250FP - Air bleeding steps: - 1

Bleed screw: 6 Nm (0.6 m • kg, 4.3 ft • lb)

i. Repeat steps (e) to (h) until of the air bubbles have been removed from the system.

PARTIE CYCLE

PURGE DE L'AIR DU SYSTEME DE FREINAGE

! AVERTISSEMENT

If bleeding is difficult, it may be necessary to let the brake fluid system stabilize for a few hours. Repeat the bleeding procedure when the tiny bubbles in the system have disappeared.

j. Add brake fluid to the level line on the reservoir.

WARNING

Check the operation of the brake after bleeding the brake system.

3. Install:

  • Protector (rear brake)
  • Diaphragm
  • Reservoir cap

YAMAHA WR250FP - Install: - 1

natural_image Technical line drawing of a mechanical lever assembly with labeled dimension (a), no text or symbols present

YAMAHA WR250FP - Install: - 2

text_image Technical diagram showing a mechanical assembly with labeled parts 1 and 2, likely for repair or maintenance instructions.

EC362040

Brake lever position adjustment steps:Loosen the locknut 1.Turn the adjusting bolt 2 until the lever position @ is within specified position.Tighten the locknut.
YAMAHA WR250FP - EC362040 - 1Locknut:5 Nm (0.5 m • kg, 3.6 ft • lb)
CAUTION:Be sure to tighten the locknut, as it will cause poor brake performance.

CAUTION:

4. Install:

- Brake lever cover

N.B.:

text_image Technical diagram of a mechanical assembly with labeled parts 1 and 2

YAMAHA WR250FP - N.B.: - 1

text_image A ③ ④ b

YAMAHA WR250FP - N.B.: - 2

text_image B ③ ⑤ C

YAMAHA WR250FP - N.B.: - 3

text_image Technical diagram showing mechanical assembly with labeled parts and dimension annotations

YAMAHA WR250FP - N.B.: - 4

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

EC364002 REAR BRAKE ADJUSTMENT

1. Check:

- Brake pedal height ⓐ Out of specification → Adjust.

YAMAHA WR250FP - Check: - 1

Brake pedal height ⓐ: 5 mm (0.20 in)

2. Adjust:

- Brake pedal height

Pedal height adjustment steps:

  • Loosen the locknut ①.
  • Turn the adjusting nut ② until the pedal height ④ is within specified height.
  • Tighten the locknut.

WARNING

  • Adjust the pedal height between the maximum A and the minimum B as shown. (In this adjustment the bolt ③ end ⑥ should protrude out of the lower adjusting nut ④ but not be less than 2 mm (0.08 in) © away from the brake pedal ⑤).
  • After the pedal height adjustment, make sure that the rear brake does not drag.

FRONT BRAKE PAD INSPECTION AND REPLACEMENT

1. Inspect:

- Brake pad thickness @ Out of specification → Replace as a set.

YAMAHA WR250FP - Inspect: - 1

Brake pad thickness: 4.4 mm (0.17 in) : 1.0 mm (0.04 in)

2. Replace:

- Brake pad

Brake pad replacement steps:

- Remove the pad pin plug ①.

REGLAGE DU FREIN ARRIERE

1. Contôler:

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - Contôler: - 1

text_image Technical diagram showing mechanical assembly with numbered component labeled ⑤

YAMAHA WR250FP - Contôler: - 2

text_image Technical diagram showing a hand using a tool to adjust or install a mechanical component, labeled with parts ⑥ and ⑦.

YAMAHA WR250FP - Contôler: - 3

text_image Technical diagram showing mechanical assembly with labeled parts (a, b) and numbered annotations (8)

YAMAHA WR250FP - Contôler: - 4

text_image Technical diagram of a mechanical assembly with numbered components for identification
  • Loosen the pad pin ②.
  • Remove the brake hose holder ③ and brake caliper ④ from the front fork.
  • Remove the pad pin and brake pads ⑤.
  • Connect the transparent hose ⑥ to the bleed screw ⑦ and place the suitable container under its end.
  • Loosen the bleed screw and push the brake caliper piston in.

CAUTION:

Do not reuse the drained brake fluid.

- Tighten the bleed screw.

YAMAHA WR250FP - Do not reuse the drained brake fluid. - 1

Bleed screw: 6 Nm (0.6 m • kg, 4.3 ft • lb)

- Install the brake pads ⑧ and pad pin.

NOTE:

  • Install the brake pads with their projections ⓐ into the brake caliper recesses Ⓐ.
  • Temporarily tighten the pad pin at this point.
  • Install the brake hose holder ⑨ and brake caliper ⑩ and tighten the pad pin ⑪.

NOTE:

Fit the brake hose holder cut © over the projection ⓐ on the front fork and clamp the brake hose.

YAMAHA WR250FP - NOTE: - 1

Bolt (brake caliper): 23 Nm (2.3 m • kg, 17 ft • lb) Pad pin: 18 Nm (1.8 m • kg, 13 ft • lb)

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

• Install the pad pin plug ⑫.

YAMAHA WR250FP - NOTE: - 2

Pad pin plug: 3 Nm (0.3 m • kg, 2.2 ft • lb)

3. Inspect:

- Brake fluid level

Refer to "BRAKE FLUID LEVEL INSPECTION" section.

4. Check:

- Brake lever operation

A softly or spongy feeling → Bleed brake system.

Refer to “BRAKE SYSTEM AIR BLEEDING” section.

YAMAHA WR250FP - Check: - 1

text_image Technical diagram showing mechanical assembly with labeled parts 'a' and directional arrows indicating motion or flow.

REAR BRAKE PAD INSPECTION AND REPLACEMENT

1. Inspect:

- Brake pad thickness ⓐ

Out of specification → Replace as a set.

YAMAHA WR250FP - Inspect: - 1

text_image Technical diagram of a mechanical assembly with numbered components labeled 1 and 2

YAMAHA WR250FP - Inspect: - 2

Brake pad thickness: 6.4 mm (0.25 in) : 1.0 mm (0.04 in)

2. Replace:

- Brake pad

Brake pad replacement steps:

  • Remove the protector ① and pad pin plug ②.
  • Loosen the pad pin ③.
  • Remove the rear wheel ④ and brake caliper ⑤.

Refer to “FRONT WHEEL AND REAR WHEEL” section in the CHAPTER 5.

YAMAHA WR250FP - Brake pad replacement steps: - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - Brake pad replacement steps: - 2

text_image Technical diagram showing hands operating a mechanical device with numbered parts labeled ⑥ and ⑦

YAMAHA WR250FP - Brake pad replacement steps: - 3

text_image Technical diagram showing mechanical assembly with numbered parts labeled 8 and 9

YAMAHA WR250FP - Brake pad replacement steps: - 4

text_image Technical diagram showing mechanical assembly steps with numbered components and a magnified detail view labeled 'a'

YAMAHA WR250FP - Brake pad replacement steps: - 5

text_image Technical diagram of a mechanical assembly with numbered components labeled 12, 13, and 14

YAMAHA WR250FP - Brake pad replacement steps: - 6

text_image Technical diagram of a mechanical assembly with numbered components labeled 15 and 16
  • Remove the pad pin ⑥ and brake pads ⑦.
  • Connect the transparent hose ⑧ to the bleed screw ⑨ and place the suitable container under its end.
  • Loosen the bleed screw and push the brake caliper piston in.

CAUTION:

Do not reuse the drained brake fluid.

- Tighten the bleed screw.

YAMAHA WR250FP - Do not reuse the drained brake fluid. - 1

Bleed screw: 6 Nm (0.6 m • kg, 4.3 ft • lb)

- Install the brake pad ⑩ and pad pin ⑪.

NOTE:

  • Install the brake pads with their projections ⓐ into the brake caliper recesses Ⓐ.
  • Temporarily tighten the pad pin at this point.
  • Install the brake caliper ⑫ and rear wheel ⑬.
    Refer to “FRONT WHEEL AND REAR WHEEL” section in the CHAPTER 5.
  • Tighten the pad pin ⑭.

YAMAHA WR250FP - NOTE: - 1

Pad pin: 18 Nm (1.8 m • kg, 13 ft • lb)

- Install the pad pin plug ⑮ and protector ⑯.

YAMAHA WR250FP - NOTE: - 2

Pad pin plug: 3 Nm (0.3 m • kg, 2.2 ft • lb)

Bolt (protector): 7 Nm (0.7 m • kg, 5.1 ft • lb)

natural_image Technical line drawing of three mechanical clip components with no text or symbols

YAMAHA WR250FP - NOTE: - 3

text_image A a T LWR B a — UPPER — LOWER

3. Inspect:

- Brake fluid level Refer to “BRAKE FLUID LEVEL INSPECTION” section.

4. Check:

- Brake pedal operation A softly or spongy feeling → Bleed brake system. Refer to “BRAKE SYSTEM AIR BLEEDING” section.

EC36b000

REAR BRAKE PAD INSULATOR INSPECTION

1. Remove:

- Brake pad Refer to "REAR BRAKE PAD INSPECTION AND REPLACEMENT" section.

2. Inspect:

- Rear brake pad insulator ① Damage → Replace.

  1. Place the brake master cylinder (reservoir tank) so that its top is in a horizontal position.

2. Inspect:

- Brake fluid level Fluid at lower level → Fill up.

① Lower level

A Front
B Rear

YAMAHA WR250FP - Inspect: - 1

WARNING

  • Use only designated quality brake fluid to avoid poor brake performance.
  • Refill with same type and brand of brake fluid; mixing fluids could result in poor brake performance.
  • Be sure that water or other contaminants do not enter master cylinder when refilling.
  • Clean up spilled fluid immediately to avoid erosion of painted surfaces or plastic parts.

  • Vérifier:

text_image Technical diagram showing a hand using a chain tag to lift a mechanical component, labeled with parts ① and ②.

YAMAHA WR250FP - WARNING - 1

text_image Technical diagram showing a hand pouring liquid into a chain, with an inset diagram illustrating the assembly process.

YAMAHA WR250FP - WARNING - 2

text_image Technical diagram showing labeled components of a mechanical assembly with numbered annotations

YAMAHA WR250FP - WARNING - 3

text_image ①②③④⑤⑥⑦⑧⑨⑩ a 12510206

SPROCKETS INSPECTION

1. Inspect:

- Sprocket teeth @

Excessive wear → Replace.

NOTE:

Replace the drive sprocket, rear wheel sprocket and drive chain as a set.

DRIVE CHAIN INSPECTION

1. Remove:

- Drive chain ①

NOTE:

Remove the drive chain using a drive chain cutter ②.

2. Clean:

- Drive chain

Brush off as much dirt as possible. Then clean the drive chain using the chain cleaner.

CAUTION:

This machine has a drive chain with small rubber O-rings ① between the side plates. Steam cleaning, high-pressure washes, certain solvent and kerosene can damage these O-rings.

3. Inspect:

  • O-ring ① (drive chain)
    Damage → Replace the drive chain.
  • Roller ②
  • Side plate ③

Damage/wear → Replace the drive chain.

4. Measure:

- Drive chain length (10 links) ⓐ

Out of specification → Replace.

YAMAHA WR250FP - Measure: - 1

Drive chain length (10 links):

: 150.1 mm (5.91 in)

CONTROLE DES PIGNONS

  1. Contrôler:

- Dents de pignon ⓐ

Usure excessive Remplacer.

N.B.:

text_image Technical diagram showing mechanical assembly steps with numbered components and hand positions

5. Check:

  • Drive chain stiffness ⓐ
    Clean and oil the drive chain and hold as illustrated.
    Stiff → Replace the drive chain.

6. Install:

- Chain joint ①

New

- O-ring ②

- Drive chain ③

NOTE:

When installing the drive chain, apply the lithium soap base grease on the chain joint and O-rings.

7. Install:

- Link plate ④

New

NOTE:

  • Press the link plate onto the chain joint using a drive chain rivetter ⑤.
  • Rivet the end of the chain joint using a drive chain rivetter ⑥.
  • After rivetting the chain joint, make sure its movement is smooth.

YAMAHA WR250FP - NOTE: - 1

natural_image Illustration of a hand using a tool to adjust a chain track with a tire, showing mechanical components (no text or symbols)

8. Lubricate:

- Drive chain

YAMAHA WR250FP - Lubricate: - 1

Drive chain lubricant: SAE 10W-30 motor oil or suitable chain lubricants

CONTROLE DE LA CHAINE DE TRANSMISSION ANTRIEBSKETTE KONTROLLIEREN ISPEZIONE DELLA CATENA DI TRASMISSIONE

INSP ADJ

[Non-Text]

5. Contrôler:

text_image Technical diagram showing mechanical assembly with labeled parts and directional arrow

EC36A060

DRIVE CHAIN SLACK ADJUSTMENT

  1. Elevate the rear wheel by placing the suitable stand under the engine.
  2. Check:

- Drive chain slack ⓐ

Above the seal guard installation bolt.

Out of specification → Adjust.

YAMAHA WR250FP - DRIVE CHAIN SLACK ADJUSTMENT - 1

Drive chain slack: 40 \~ 50 mm (1.6 \~ 2.0 in)

NOTE:

Before checking and/or adjusting, rotate the rear wheel through several revolutions and check the slack several times to find the tightest point. Check and/or adjust the drive chain slack with the rear wheel in this “tight chain” position.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with labeled parts 1, 2, and 3
  1. Adjust:

- Drive chain slack

Drive chain slack adjustment steps:Loosen the axle nut 1 and locknuts 2.Adjust the drive chain slack by turning the adjusters 3.
To tighten → Turn the adjuster 3 counterclockwise.To loosen → Turn the adjuster 3 clockwise and push wheel forward.
Turn each adjuster exactly the same amount to maintain correct axle alignment.(There are marks 4 on each side of the drive chain puller alignment.)NOTE:Turn the adjuster so that the drive chain is in line with the sprocket, as viewed from the rear.CAUTION:Too small drive chain slack will overload the engine and other vital parts; keep the slack within the specified limits.Tighten the axle nut while pushing down the drive chain.
YAMAHA WR250FP - NOTE: - 2Axle nut:125 Nm (12.5 m • kg, 90 ft • lb)
Tighten the locknuts.

REGLAGE DE LA FLECHE DE CHAINE DE TRANSMISSION

natural_image Line drawing of a bicycle wheel assembly with a steering wheel and gear mechanism (no text or symbols)

YAMAHA WR250FP - REGLAGE DE LA FLECHE DE CHAINE DE TRANSMISSION - 1

natural_image Technical line drawing of a mechanical clamp or bracket assembly (no text or symbols)

YAMAHA WR250FP - REGLAGE DE LA FLECHE DE CHAINE DE TRANSMISSION - 2

text_image Technical diagram of a mechanical assembly with labeled parts a and b, showing gear and tool connections.

YAMAHA WR250FP - REGLAGE DE LA FLECHE DE CHAINE DE TRANSMISSION - 3

text_image S→H ①

EC36C000

FRONT FORK INSPECTION

1. Inspect:

- Front fork smooth action

Operate the front brake and stroke the front fork.

Unsmooth action/oil leakage → Repair or replace.

EC36D001

FRONT FORK OIL SEAL AND DUST SEAL CLEANING

1. Remove:

  • Protector
  • Dust seal ①

NOTE:

Use a thin screw driver, and be careful not to damage the inner fork tube and dust seal.

2. Clean:

  • Dust seal ⓐ
  • Oil seal ⓑ

NOTE:

  • Clean the dust seal and oil seal after every run.
  • Apply the lithium soap base grease on the inner tube.

FRONT FORK INTERNAL PRESSURE RELIEVING

NOTE:

If the front fork initial movement feels stiff during a run, relieve the front fork internal pressure.

  1. Elevate the front wheel by placing a suitable stand under the engine.
  2. Remove the air bleed screw ① and release the internal pressure from the front fork.
  3. Install:

- Air bleed screw

YAMAHA WR250FP - NOTE: - 1

1 Nm (0.1 m · kg, 0.7 ft · lb)

CONTROLE DE LA FOURCHE AVANT

1. Contrôler:

text_image S←H b a ①

EC36H002

FRONT FORK REBOUND DAMPING FORCE ADJUSTMENT

  1. Adjust:

- Rebound damping force By turning the adjuster ①.

Stiffer ① → Increase the rebound damping force. (Turn the adjuster ① in.) Softer ⑥ → Decrease the rebound damping force. (Turn the adjuster ① out.)

Extent of adjustment
MaximumMinimum
Fully turned in position20 clicks out (from maximum position)

• STANDARD POSITION:

This is the position which is back by the specific number of clicks from the fully turned-in position.

YAMAHA WR250FP - FRONT FORK REBOUND DAMPING FORCE ADJUSTMENT - 1

Standard position:

12 clicks out
* 9 clicks out
** 8 clicks out

* For EUROPE
** For AUS, NZ and ZA

CAUTION:

Do not force the adjuster past the minimum or maximum extent of adjustment. The adjuster may be damaged.

WARNING

Always adjust each front fork to the same setting. Uneven adjustment can cause poor handling and loss of stability.

REGLAGE DE LA FORCE D'AMORTISSEMENT DE DETENTE DE LA FOURCHE AVANT

1. Régler:

text_image Technical diagram of a mechanical component with labeled parts and directional arrows indicating rotation or movement.

EC36J001 FRONT FORK COMPRESSION DAMPING FORCE ADJUSTMENT

  1. Remove:

- Rubber cap

  1. Adjust:

- Compression damping force By turning the adjuster ①.

Stiffer ① → Increase the compression damping force. (Turn the adjuster ① in.)

Softer ⑥ → Decrease the compression damping force. (Turn the adjuster ① out.)

YAMAHA WR250FP - EC36J001 FRONT FORK COMPRESSION DAMPING FORCE ADJUSTMENT - 1Extent of adjustment
MaximumMinimum
Fully turned in position20 clicks out (from maximum position)

• STANDARD POSITION:

This is the position which is back by the specific number of clicks from the fully turned-in position.

YAMAHA WR250FP - EC36J001 FRONT FORK COMPRESSION DAMPING FORCE ADJUSTMENT - 2

Standard position:

14 clicks out

* 15 clicks out

* For AUS, NZ and ZA

CAUTION:

Do not force the adjuster past the minimum or maximum extent of adjustment. The adjuster may be damaged.

WARNING

Always adjust each front fork to the same setting. Uneven adjustment can cause poor handling and loss of stability.

  1. Install:

- Rubber cap

REGLAGE DE LA FORCE D'AMORTISSEMENT DE COM- PRESSION DE LA FOURCHE AVANT

  1. Déposer:

- Capuchon en caoutchouc

  1. Régler:
natural_image Mechanical assembly diagram showing a gear and chain mechanism with no visible text or symbols

YAMAHA WR250FP - REGLAGE DE LA FORCE D'AMORTISSEMENT DE COM- PRESSION DE LA FOURCHE AVANT - 1

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②

YAMAHA WR250FP - REGLAGE DE LA FORCE D'AMORTISSEMENT DE COM- PRESSION DE LA FOURCHE AVANT - 2

natural_image Technical line drawing of a mechanical spring assembly with dimension label (a), no text or symbols present

EC36K000

REAR SHOCK ABSORBER INSPECTION

1. Inspect:

  • Swingarm smooth action
    Abnormal noise/unsmooth action → Grease the pivoting points or repair the pivoting points.
    Damage/oil leakage → Replace.

EC36M013

REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT

  1. Elevate the rear wheel by placing the suitable stand under the engine.
  2. Remove:
  3. Rear frame
  4. Loosen:
  5. Locknut ①
  6. Adjust:
  7. Spring preload By turning the adjuster ②.
Stiffer → Increase the spring preload.(Turn the adjuster 2 in.)
Softer → Decrease the spring preload.(Turn the adjuster 2 out.)
Spring length (installed) a:
Standard lengthExtent of adjustment
244 mm (9.61 in)* 247 mm (9.72 in)** 243.5 mm (9.59 in)240.5 ~ 258.5 mm(9.47 ~ 10.18 in)

* For EUROPE
** For AUS, NZ and ZA

NOTE:

  • Be sure to remove all dirt and mud from around the locknut and adjuster before adjustment.
  • The length of the spring (installed) changes 1.5 mm (0.06 in) per turn of the adjuster.

CAUTION:

Never attempt to turn the adjuster beyond the maximum or minimum setting.

  1. Tighten:
  2. Locknut
  3. Install:
  4. Rear frame

YAMAHA WR250FP - Never attempt to turn the adjuster beyond the maximum or minimum setting. - 1

29 Nm (2.9 m · kg, 21 ft · lb)

text_image Technical diagram showing mechanical assembly with labeled parts and directional arrows

EC36N014 REAR SHOCK ABSORBER REBOUND DAMPING FORCE ADJUSTMENT

1. Adjust:

- Rebound damping force By turning the adjuster ①.

Stiffer ① → Increase the rebound damping force. (Turn the adjuster ① in.) Softer ⑥ → Decrease the rebound damping force. (Turn the adjuster ① out.)

Extent of adjustment
MaximumMinimum
Fully turned in position20 clicks out (from maximum position)

YAMAHA WR250FP - Adjust: - 1

text_image S b a H

• STANDARD POSITION:

This is the position which is back by the specific number of clicks from the fully turned-in position. (Which align the punch mark ⓐ on the adjuster with the punch mark ⓑ on the bracket.)

YAMAHA WR250FP - • STANDARD POSITION: - 1

Standard position: About 7 clicks out *, ** About 10 clicks out

* For EUROPE
** For AUS, NZ and ZA

CAUTION:

Do not force the adjuster past the minimum or maximum extent of adjustment. The adjuster may be damaged.

REGLAGE DE LA FORCE D'AMORTISSEMENT DE DETENTE DE L'AMORTISSEUR ARRIERE

1. Régler:

- Low compression damping force By turning the adjuster ①.

Stiffer ⓐ → Increase the low compression damping force. (Turn the adjuster ① in.)

Softer ⑥ → Decrease the low compression damping force. (Turn the adjuster ① out.)

Extent of adjustment
MaximumMinimum
Fully turned in position20 clicks out (from maximum position)

YAMAHA WR250FP - Régler: - 1

text_image a b

• STANDARD POSITION:

This is the position which is back by the specific number of clicks from the fully turned-in position. (Which align the punch mark ⓐ on the adjuster with the punch mark ⓑ on the high compression damping adjuster.)

YAMAHA WR250FP - • STANDARD POSITION: - 1

Standard position: About 9 clicks out *, ** About 12 clicks out

* For EUROPE
** For AUS, NZ and ZA

CAUTION:

Do not force the adjuster past the minimum or maximum extent of adjustment. The adjuster may be damaged.

REGLAGE DE LA FORCE D'AMORTISSEMENT A BASSE COMPRESSION DE L'AMORTISSEUR ARRIERE

1. Régler:

text_image Technical diagram of a mechanical component with labeled parts (a, b) and numbered callouts (1, 2)

EC36d000

REAR SHOCK ABSORBER HIGH COMPRESSION DAMPING FORCE ADJUSTMENT

1. Adjust:

- High compression damping force By turning the adjuster ①.

Stiffer ⓐ → Increase the high compression damping force. (Turn the adjuster ① in.)

Softer ⑥ → Decrease the high compression damping force. (Turn the adjuster ① out.)

Extent of adjustment
MaximumMinimum
Fully turned in position2 turns out (from maximum position)

YAMAHA WR250FP - Adjust: - 1

text_image a b

• STANDARD POSITION:

This is the position which is back by the specific number of turns from the fully turned-in position. (Which align the punch mark ⓐ on the adjuster with the punch mark ⓑ on the adjuster body.)

YAMAHA WR250FP - • STANDARD POSITION: - 1

Standard position:

About 1-1/2 turns out * About 1-1/4 turns out

* For AUS, NZ and ZA

CAUTION:

Do not force the adjuster past the minimum or maximum extent of adjustment. The adjuster may be damaged.

REGLAGE DE LA FORCE D'AMORTISSEMENT A HAUTE COMPRESSION DE L'AMORTIS-SEUR ARRIERE

1. Régler:

natural_image Illustration of hands adjusting a pressure gauge with a tool, no text or symbols present

EC36Q000

TIRE PRESSURE CHECK

1. Measure:

- Tire pressure

Out of specification → Adjust.

YAMAHA WR250FP - Measure: - 1

Standard tire pressure: 100 kPa (1.0 kgf/cm ^2 , 15 psi)

NOTE:

  • Check the tire while it is cold.
  • Loose bead stoppers allow the tire to slip off its position on the rim when the tire pressure is low.
  • A tilted tire valve stem indicates that the tire slips off its position on the rim.
  • If the tire valve stem is found tilted, the tire is considered to be slipping off its position. Correct the tire position.

YAMAHA WR250FP - NOTE: - 1

text_image ① 12010801

EC36S002

SPOKES INSPECTION AND TIGHTENING

1. Inspect:

- Spokes ①

Bend/damage → Replace.

Loose spoke → Retighten.

2. Tighten:

- Spokes

3 Nm (0.3 m · kg, 2.2 ft · lb)

NOTE:

Be sure to retighten these spokes before and after break-in. After a practice or a race check spokes for looseness.

YAMAHA WR250FP - NOTE: - 1

natural_image Mechanical diagram showing a hand operating a gear and rotating a wheel with a tool, no text or symbols present

EC36T000

WHEEL INSPECTION

1. Inspect:

- Wheel runout

Elevate the wheel and turn it.

Abnormal runout → Replace.

CONTROLE DE PRESSION DES PNEUS

  1. Mesurer:
natural_image Mechanical diagram showing a gear and wheel assembly with rotational arrows (no text or symbols)

YAMAHA WR250FP - CONTROLE DE PRESSION DES PNEUS - 1

natural_image Diagram of a hand using a tool to rotate or rotate a circular object, showing motion arrows (no text or symbols)

YAMAHA WR250FP - CONTROLE DE PRESSION DES PNEUS - 2

natural_image Technical line drawing of a mechanical assembly with directional arrows indicating motion (no text or symbols)

YAMAHA WR250FP - CONTROLE DE PRESSION DES PNEUS - 3

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②

2. Inspect:

- Bearing free play Exist play → Replace.

STEERING HEAD INSPECTION AND ADJUSTMENT

  1. Elevate the front wheel by placing a suitable stand under the engine.

2. Check:

- Steering stem Grasp the bottom of the forks and gently rock the fork assembly back and forth. Free play → Adjust steering head.

3. Check:

- Steering smooth action Turn the handlebar lock to lock. Unsmooth action → Adjust steering ring nut.

4. Adjust:

- Steering ring nut

Steering ring nut adjustment steps:Remove the headlight.Remove the handlebar and upper bracket.Loosen the steering ring nut 1 using the steering nut wrench 2.
YAMAHA WR250FP - Adjust: - 1Steering nut wrench:YU-33975/90890-01403

CONTROLE ET REGLAGE DE LA TETE DE FOURCHE LENKKOPF KONTROLLIEREN UND EINSTELLEN ISPEZIONE E REGOLAZIONE DELLA TESTA DI STERZO

2. Vérifier:

Hakenschlüssel YU-33975/90890-01403

4. Regolare:

- Ghiera

text_image Technical diagram of a mechanical assembly with numbered components labeled ③, ④, and ③

YAMAHA WR250FP - Regolare: - 1

text_image ⑩ ⑨ ⑦ ⑥ ⑤ ⑧ a FWD

- Tighten the steering ring nut ③ using steering nut wrench ④.

NOTE: Set the torque wrench to the steering nut wrench so that they form a right angle.

YAMAHA WR250FP - Regolare: - 2

Steering nut wrench: YU-33975/90890-01403

YAMAHA WR250FP - Regolare: - 3

Steering ring nut (initial tightening): 38 Nm (3.8 m • kg, 27 ft • lb)

- Loosen the steering ring nut one turn. - Retighten the steering ring nut using the steering nut wrench.

WARNING

Avoid over-tightening.

YAMAHA WR250FP - WARNING - 1

Steering ring nut (final tightening): 7 Nm (0.7 m • kg, 5.1 ft • lb)

- Check the steering stem by turning it lock to lock. If there is any binding, remove the steering stem assembly and inspect the steering bearings. - Install the upper bracket ⑤, steering stem nut ⑥, handlebar ⑦, handlebar holder ⑧ and headlight ⑨.

NOTE: ____ - The upper handlebar holder should be installed with the punched mark ⓐ forward. - Insert the end of fuel breather hose ⑩ into the hole of the steering stem.

CAUTION:

First tighten the bolts on the front side of the handlebar holder, and then tighten the bolts on the rear side.

YAMAHA WR250FP - CAUTION: - 1

Steering stem nut: 145 Nm (14.5 m • kg, 105 ft • lb) Handlebar upper holder: 28 Nm (2.8 m • kg, 20 ft • lb) Pinch bolt (upper bracket): 23 Nm (2.3 m • kg, 17 ft • lb) Headlight: 7 Nm (0.7 m • kg, 5.1 ft • lb)

CONTROLE ET REGLAGE DE LA TETE DE FOURCHE LENKKOPF KONTROLLIEREN UND EINSTELLEN ISPEZIONE E REGOLAZIONE DELLA TESTA DI STERZO

Hakenschlüssel YU-33975/90890-01403

YAMAHA WR250FP - CONTROLE ET REGLAGE DE LA TETE DE FOURCHE LENKKOPF KONTROLLIEREN UND EINSTELLEN ISPEZIONE E REGOLAZIONE DELLA TESTA DI STERZO - 1

To ensure smooth operation of all components, lubricate your machine during setup, after break-in, and after every race.

① All control cable
② Clutch lever pivot
③ Shift pedal pivot
④ Footrest pivot
⑤ Throttle-to-handlebar contact
⑥ Drive chain
⑦ Tube guide cable winding portion
⑧ Throttle cable end
⑨ Clutch cable end
⑩ Decompression cable end

A Use Yamaha cable lube or equivalent on these areas.
B Use SAE 10W-30 motor oil or suitable chain lubricants.
C Lubricate the following areas with high quality, lightweight lithium-soap base grease.

CAUTION:

Wipe off any excess grease, and avoid getting grease on the brake discs.

AYAMAHA WR250FP - CAUTION: - 1AYAMAHA WR250FP - CAUTION: - 2AYAMAHA WR250FP - CAUTION: - 3
AYAMAHA WR250FP - CAUTION: - 4AYAMAHA WR250FP - CAUTION: - 5BYAMAHA WR250FP - CAUTION: - 6
CYAMAHA WR250FP - CAUTION: - 7CYAMAHA WR250FP - CAUTION: - 8

GRAISSAGE

text_image Technical diagram of a mechanical component with labeled parts and directional arrow

EC370000

ELECTRICAL

EC371001

SPARK PLUG INSPECTION

  1. Remove:

- Spark plug

  1. Inspect:

- Electrode ①

Wear/damage → Replace.

- Insulator color ②

Normal condition is a medium to light tan color.

Distinctly different color → Check the engine condition.

NOTE:

When the engine runs for many hours at low speeds, the spark plug insulator will become sooty, even if the engine and carburetor are in good operating condition.

  1. Measure:

- Plug gap ⓐ

Use a wire gauge or thickness gauge.

Out of specification → Regap.

YAMAHA WR250FP - NOTE: - 1

Spark plug gap: 0.7 \~ 0.8 mm (0.028 \~ 0.031 in)

  1. Clean the plug with a spark plug cleaner if necessary.

YAMAHA WR250FP - NOTE: - 2

text_image 18040301 a b
  1. Tighten:

- Spark plug

13 Nm (1.3 m · kg, 9.4 ft · lb)

NOTE:

  • Before installing a spark plug, clean the gasket surface and plug surface.
  • Finger-tighten ⓐ the spark plug before torquing to specification ⓑ.

PARTIE ELECTRIQUE CONTROLE DE LA BOUGIE

  1. Déposer:

- Bougie

  1. Contrôler:

- Electrode ①

text_image Technical diagram showing mechanical assembly with labeled component ① and numbered parts

YAMAHA WR250FP - PARTIE ELECTRIQUE CONTROLE DE LA BOUGIE - 1

natural_image Line drawing of a hand using a tool to adjust or install an engine component (no text or symbols visible)

IGNITION TIMING CHECK

1. Remove:

- Timing mark accessing screw ①

2. Attach:

  • Timing light
  • Inductive tachometer

To the spark plug lead.

YAMAHA WR250FP - Attach: - 1

Timing light: YM-33277-A/90890-03141

Inductive tachometer:

YU-8036-B

Engine tachometer:

90890-03113

YAMAHA WR250FP - Attach: - 2

text_image a b

3. Check:

- Ignition timing

Checking steps:Start the engine and let it warm up. Let the engine run at the specified speed.
[xWTW]Engine speed:1,800 ~ 2,100 r/min
• Visually check the stationary pointer a is within the firing range b on the rotor.Incorrect firing range → Check rotor and pickup assembly.

4. Install:

- Timing mark accessing screw

CONTROLE DE L'AVANCE A L'ALLUMAGE

1. Déposer:

natural_image Technical line drawing of a mechanical component with no visible text or symbols

YAMAHA WR250FP - Déposer: - 1

text_image Technical diagram of a mechanical assembly with numbered components labeled ① and ②

REPLACING THE HEADLIGHT BULBS

1. Remove:

- Headlight Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4.

2. Remove:

- Headlight bulb holder cover ①

3. Detach:

- Headlight bulb holder ①

4. Remove:

- Headlight bulb ②

WARNING

Since the headlight bulb gets extremely hot, keep flammable products and your hands away from the bulb unit it has cooled down.

5. Install:

- Headlight bulb New Secure the new headlight bulb with the headlight bulb holder.

CAUTION:

Avoid touching the glass part of the headlight bulb to keep it free form oil, otherwise the transparency of the glass, the life of the bulb and the luminous flux will be adversely affected. If the headlight bulb gets soiled, thoroughly clean it with a cloth moistened with alcohol or lacquer thinner.

6. Attach:

- Headlight bulb holder

7. Install:

• Headlight bulb holder cover

8. Install:

• Headlight bolt (left and right)

10 Nm (1.0 m · kg, 7.2 ft · lb)

- Headlight bolt (lower)

YAMAHA WR250FP - Install: - 1

7 Nm (0.7 m · kg, 5.1 ft · lb)

Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4.

REMPLACER LES AMPOULES DU PHARE

  1. Déposer:

- Phare

text_image Technical diagram of a vehicle front panel with labeled parts a and b, and part ①

ADJUSTING THE HEADLIGHT BEAMS

1. Adjust:

• Headlight beam (vertically)

Adjusting steps:• Turn the adjusting screw 1 in direction a or b.
Direction aHeadlight beam is raised.
Direction bHeadlight beam is lowered.

REGLAGES DES FAISCEAUX DES PHARES

1. Régler:

Extent of removal:
① Seat removal
② Fuel tank removal
③ Side covers removal
④ Headlight removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalSEAT, FUEL TANK AND SIDE COVERS REMOVALTurn the fuel cock to “OFF”. Disconnect the fuel hose.
1↓3↓2↓3↓4↓1Seat1Remove on fuel tank side.
2Air scoop (left and right)2
3Fitting band1
4Bolt (fuel tank)2
5Fuel tank1
6Left side cover1
7Right side cover1
8Headlight coupler1
9Headlight1

MOTEUR

SELLE, RESERVOIR DE CARBURANT ET CACHES LATERAUX

YAMAHA WR250FP - SELLE, RESERVOIR DE CARBURANT ET CACHES LATERAUX - 1

A Except for USA
Extent of removal:
① Silencer removal
② Exhaust pipe removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalEXHAUST PIPE AND SILENCER REMOVALRight side coverRefer to “SEAT, FUEL TANK AND SIDE COVERS” section.
12↓1Bolt (silencer clamp)1Only loosening.
2Bolt [silencer (front)]1
3Bolt [silencer (rear)]1
4Silencer1
5Silencer clamp1
6Nut (exhaust pipe)1
7Bolt (exhaust pipe)1
8Exhaust pipe1
9Gasket2

TUYAU D'ECHAPPEMENT ET SILENCIEUX

YAMAHA WR250FP - TUYAU D'ECHAPPEMENT ET SILENCIEUX - 1

A Excepté pour USA

natural_image Technical line drawing of a pipe fitting with a separate inset showing a circular component and a labeled part (1), no text or symbols present.

YAMAHA WR250FP - TUYAU D'ECHAPPEMENT ET SILENCIEUX - 2

text_image Technical diagram of a mechanical assembly with numbered components, likely for assembly or maintenance reference.

INSPECTION

Silencer and exhaust pipe

1. Inspect:

  • Gasket ①
    Damage → Replace.

ASSEMBLY AND INSTALLATION

Silencer and exhaust pipe

1. Install:

  • Gasket New
  • Exhaust pipe ①
  • Nut (exhaust pipe) ②

13 Nm (1.3 m · kg, 9.4 ft · lb)

- Bolt (exhaust pipe) ③

First, temporarily tighten the nut (exhaust pipe), then tighten the bolt (exhaust pipe) 20 Nm (2.0 m • kg, 14 ft • lb). After that, retighten the nut (exhaust pipe) 13 Nm (1.3 m • kg, 9.4 ft • lb) and then the bolt (exhaust pipe) 24 Nm (2.4 m • kg, 17 ft • lb).

YAMAHA WR250FP - Install: - 1

text_image Technical diagram of a mechanical assembly with numbered components and a label 'New' in the corner.

2. Install:

- Silencer clamp ①

Extent of removal:
① Radiator removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalRADIATOR REMOVALDrain the coolant.Seat, fuel tank and leftSide coverRefer to “COOLANT REPLACEMENT” section in the CHAPTER 3.Refer to “SEAT, FUEL TANK AND SIDE COVERS” section.
11Radiator guard2Only loosening.
2Radiator hose clamp8
3Radiator hose 11
4Left radiator1
5Radiator hose 31
6Coolant reservoir hose1
7Right radiator1
8Radiator hose 21
9Radiator hose 41
10Radiator pipe1
11Coolant reservoir breather hose1
12Coolant reservoir1

RADIATEUR

YAMAHA WR250FP - RADIATEUR - 1

Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be blown out under pressure, which could cause serious injury.

When the engine has cooled, open the radiator cap by the following procedure:

Place a thick rag, like a towel, over the radiator cap, slowly rotate the cap counterclockwise to the detent. This procedure allows any residual pressure to escape. When the hissing sound has stopped, press down on the cap while turning counterclockwise and remove it.

YAMAHA WR250FP - RADIATEUR - 2

text_image Diagram illustrating a mechanical or structural assembly with labeled parts and an inset magnified view of a threaded component.

YAMAHA WR250FP - RADIATEUR - 3

text_image New ① ② ③ B

YAMAHA WR250FP - RADIATEUR - 4

text_image Technical diagram of a heat exchanger with labeled components 1, 2, and 3

EC454000

INSPECTION

EC444100

Radiator

  1. Inspect:

  2. Radiator core ①
    Obstruction → Blow out with compressed air through rear of the radiator. Bent fin → Repair/replace.

EC455000

ASSEMBLY AND INSTALLATION

Radiator

  1. Install:

  2. O-ring ① New

  3. Radiator pipe ②
  4. Bolt (radiator pipe) ③

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Apply the lithium soap base grease on the O-ring.

  1. Install:

  2. Radiator hose 4 (longer) ①

  3. Radiator hose 2 (shorter) ② To right radiator ③.

REMARQUES CONCERNANT LA MANIPULATION

! AVERTISSEMENT

- Joint torque ① New

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - ! AVERTISSEMENT - 1

text_image Technical diagram showing mechanical assembly with numbered components and labeled parts

YAMAHA WR250FP - ! AVERTISSEMENT - 2

text_image Technical diagram showing mechanical assembly with labeled parts and numbered annotations

YAMAHA WR250FP - ! AVERTISSEMENT - 3

text_image COOLANT FULL LOW

3. Install:

  • Right radiator ①
  • Bolt (right radiator) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

- Radiator hose 3 ③

Refer to "CABLE ROUTING DIAGRAM" section in the CHAPTER 2.

4. Install:

  • Left radiator ①
  • Bolt (left radiator) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

2 Nm (0.2 m · kg, 1.4 ft · lb)

  • Radiator hose 1 ③

Refer to “CABLE ROUTING DIAGRAM” section in the CHAPTER 2.

5. Tighten:

  • Radiator hose clamp ④
    2 Nm (0.2 m · kg, 1.4 ft · lb)

6. Install:

  • Radiator guard ①
  • Bolt (radiator guard) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Fit the hook ⓐ on the inner side first into the radiator.

7. Install:

  • Coolant reservoir ①
  • Clamp ②
  • Bolt [coolant reservoir (front)] ③

7 Nm (0.7 m · kg, 5.1 ft · lb)

  • Bolt [coolant reservoir (rear)] ④
    11 Nm (1.1 m · kg, 8.0 ft · lb)

  • Coolant reservoir hose ⑤

  • Coolant reservoir breather hose ⑥ Refer to “CABLE ROUTING DIAGRAM” section in the CHAPTER 2.

8. Fill:

  • Radiator
  • Engine
  • Coolant reservoir Refer to “COOLANT REPLACEMENT” section in the CHAPTER 3.

3. Monter:

Extent of removal:
① Carburetor removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCARBURETOR REMOVALSeat and fuel tankRefer to “SEAT, FUEL TANK AND SIDE COVERS” section.
11Clamp2
2Throttle position sensor lead coupler1
3Throttle cable cover1
4Throttle cable2
5Throttle cable cap1
6Clamp (air filter joint)1Loosen the screw (air filter joint).
7Clamp (carburetor joint)2Loosen the screws (carburetor joint).
8Carburetor assembly1
9Carburetor joint1

CARBURATEUR

Extent of removal:
① Carburetor disassembly

Extent of removalOrderPart nameQ'tyRemarks
CARBURETOR DISASSEMBLY
1Carburetor breather hose4
2Valve lever housing cover1
3Screw (throttle shaft)1
4Throttle valve1
5Needle holder1
6Jet needle1
7Accelerator pump cover1
8Spring1
9Diaphragm (accelerator pump)1
10Air cut valve cover1
11Spring (air cut valve)1
12Diaphragm (air cut valve)1
13Float chamber1
14Leak jet1
15Pilot screw1Refer to “REMOVAL POINTS”.
16Float pin1

DEMONTAGE DU CARBURATEUR

text_image Technical diagram of a mechanical assembly with labeled parts, showing components like gears and shafts.

YAMAHA WR250FP - DEMONTAGE DU CARBURATEUR - 1

natural_image Technical line drawing of a mechanical component with no visible text or symbols

HANDLING NOTE

CAUTION:

Do not loosen the screws (throttle position sensor) ① except when changing the throttle position sensor due to failure because it will cause a drop in engine performance.

REMOVAL POINTS

Pilot screw

  1. Remove:

- Pilot screw ①

NOTE:

To optimize the fuel flow at a small throttle opening, each machine's pilot screw has been individually set at the factory. Before removing the pilot screw, turn it in fully and count the number of turns. Record this number as the factory-set number of turns out.

YAMAHA WR250FP - NOTE: - 1

natural_image Line drawing of a hand using a tool to adjust or install a mechanical component (no text or symbols present)

INSPECTION

Carburetor

  1. Inspect:

- Carburetor body

Contamination → Clean.

NOTE:

  • Use a petroleum based solvent for cleaning. Blow out all passages and jets with compressed air.
  • Never use a wire.

REMARQUE CONCERNANT LES MANIPULATIONS

ATTENTION:

text_image Technical diagram showing exploded view of seven mechanical components with numbered labels

2. Inspect:

  • Main jet ①
  • Pilot jet ②
  • Needle jet ③
  • Starter jet ④
  • Main air jet ⑤
  • Pilot air jet ⑥
  • Leak jet ⑦

Damage → Replace.

Contamination → Clean.

NOTE:

  • Use a petroleum based solvent for cleaning. Blow out all passages and jets with compressed air.
  • Never use a wire.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing three labeled mechanical components with directional arrows and cross-sectional views

Needle valve

1. Inspect:

  • Needle valve ①
  • Valve seat ②

Grooved wear ⓐ → Replace.

Dust ⓑ and Ⓒ → Clean.

NOTE:

Replace the needle valve and valve seat as a set.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing mechanical assembly with labeled component '①' and directional arrow indicating movement

EC464301

Throttle valve

1. Check:

  • Free movement
    Stick → Repair or replace.

NOTE:

Insert the throttle valve ① into the carburetor body, and check for free movement.

EC464401

Jet needle

1. Inspect:

  • Jet needle ①
    Bends/wear → Replace.
  • Clip groove
    Free play exists/wear → Replace.
  • Clip position

YAMAHA WR250FP - Inspect: - 1

text_image 1 2 3 4 5 6 7 ①
Standard clip position: No.3 Groove * No.4 Groove

* For EUROPE

2. Contrôler:

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - Contrôler: - 1

natural_image Technical line drawing of a mechanical device with two components and a labeled part (b), no readable text or symbols present.

YAMAHA WR250FP - Contrôler: - 2

natural_image Technical line drawing of a mechanical clamp or bracket assembly (no text or symbols)

Float height

1. Measure:

- Float height ⓐ

Out of specification → Adjust.

YAMAHA WR250FP - Measure: - 1

Float height: 8.0 mm (0.31 in)

Measurement and adjustment steps:

- Hold the carburetor in an upside down position.

NOTE:

  • Slowly tilt the carburetor in the opposite direction, then take the measurement when the needle valve aligns with the float arm.
  • If the carburetor is level, the weight of the float will push in the needle valve, resulting in an incorrect measurement.
  • Measure the distance between the mating surface of the float chamber and top of the float using a vernier calipers.

NOTE:

The float arm should be resting on the needle valve, but not compressing the needle valve.

  • If the float height is not within specification, inspect the valve seat and needle valve.
  • If either is worn, replace them both.
  • If both are fine, adjust the float height by bending the float tab ⑥ on the float.
  • Recheck the float height.

EC464600

Float

1. Inspect:

- Float ①

Damage → Replace.

Hauteur du flotteur

  1. Mesurer:
text_image Technical diagram of two mechanical fasteners with labeled parts ① and ②

YAMAHA WR250FP - Hauteur du flotteur - 1

text_image Technical diagram of a mechanical component with numbered parts for identification

YAMAHA WR250FP - Hauteur du flotteur - 2

text_image Technical diagram showing exploded view of mechanical components with numbered parts labeled 1 through 6

YAMAHA WR250FP - Hauteur du flotteur - 3

text_image Technical diagram showing four labeled mechanical components: a coiled spring, a housing with a valve, and a separate circular component with a pin.

YAMAHA WR250FP - Hauteur du flotteur - 4

text_image Technical diagram of a mechanical assembly with numbered components labeled ① and ②

Starter plunger

1. Inspect:

  • Cold starter plunger ①
  • Hot starter plunger (red) ②
    Wear/damage → Replace.

Accelerator pump

1. Inspect:

• Diaphragm (accelerator pump) ①
- Spring (accelerator pump) ②
- Accelerator pump cover ③
- O-ring ④
- Push rod ⑤
Tears (diaphragm)/damage → Replace.
Dirt → Clean.

2. Inspect:

  • Throttle shaft ①
  • Spring ②
  • Lever 1 ③
  • Spring 1 ④
  • Lever 2 ⑤
  • Spring 2 ⑥
    Dirt → Clean.

Air cut valve

1. Inspect:

• Diaphragm (air cut valve) ①
- Spring (air cut valve) ②
- Air cut valve cover ③
- O-ring ④
Tears (diaphragm)/damage → Replace.

ASSEMBLY AND INSTALLATION

Carburetor

1. Install:

  • Hot starter plunger (red) ①
  • Cold starter plunger ②

Plongeur de starter

1. Contrôler:

text_image Technical diagram of a mechanical component with numbered parts, likely for assembly or identification.

YAMAHA WR250FP - Contrôler: - 1

text_image Technical diagram of a mechanical clamp or spring assembly with labeled parts ①, ②, and ③

YAMAHA WR250FP - Contrôler: - 2

text_image Technical diagram of a mechanical component with labeled parts 1 and 2

YAMAHA WR250FP - Contrôler: - 3

text_image Technical diagram of automotive engine components with labeled parts (a) and (b)

YAMAHA WR250FP - Contrôler: - 4

text_image Technical diagram showing mechanical assembly with labeled parts, including a tool and component numbered 1 and 2.

2. Install:

  • Main air jet ①
  • Pilot air jet ②
  • O-ring ③
  • Intake joint ④

5 Nm (0.5 m · kg, 3.6 ft · lb)

3. Install:

  • Spring 1 ①
  • Lever 1 ②
    To lever 2 ③.

NOTE: ____

Make sure the spring 1 fits on the stopper ⓐ of the lever 2.

4. Install:

  • Spring 2 ①
    To lever 2 ②.

5. Install:

- Push rod link lever assembly ①

NOTE: ____

Make sure the stopper ⓐ of the spring 2 fits into the recess ⓑ in the carburetor.

6. Install:

  • Washer ①
  • Circlip ②

2. Monter:

text_image Technical diagram of a car suspension system with labeled components including spring, damper, and valve parts

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram showing mechanical assembly with numbered components and a close-up view of a component labeled 'a' and 'b'.

YAMAHA WR250FP - Monter: - 2

natural_image Technical line drawing of a mechanical assembly with hands and gears (no text or symbols)

YAMAHA WR250FP - Monter: - 3

text_image Technical diagram of a mechanical assembly with labeled parts including gears, springs, and adjustment indicators

YAMAHA WR250FP - Monter: - 4

text_image Technical diagram showing mechanical assembly with numbered components, likely for engine or valve maintenance

7. Install:

  • Spring ①
  • Joint collar ②

To throttle shaft ③.

NOTE: \_\_\_\_

Install the bigger hook Ⓐ of the spring fits on the stopper ⓑ of the throttle shaft pulley.

8. Install:

  • Throttle shaft assembly ①
  • Washer (metal) ②
  • Washer (resin) ③
  • Valve lever ④

NOTE: \_\_\_\_

  • Apply the fluorochemical grease on the bearings.
  • Fit the projection ⓐ on the throttle shaft assembly into the slot ⓑ in the throttle position sensor.
  • Make sure the stopper © of the spring fits into the recess in the carburetor.
  • Turn the throttle shaft assembly left while holding down the lever 1 ⑤ and fit the throttle stop screw tip ⓓ to the stopper Ⓔ of the throttle shaft assembly pulley.

9. Install:

- Push rod ①

NOTE: \_\_\_\_

While holding down the lever 1 ②, insert the push rod farthest into the carburetor.

7. Installer:

  • Ressort ①
  • Manchette de joint ②
text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - Installer: - 1

text_image Technical diagram of a mechanical assembly with numbered parts labeled ① to ④

YAMAHA WR250FP - Installer: - 2

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - Installer: - 3

text_image Technical diagram of a mechanical assembly with numbered parts for identification

10. Install:

  • Starter jet ①
  • Pilot jet ②
  • Spacer ③
  • Needle jet ④
  • Main jet ⑤

11. Install:

  • Valve seat
  • Screw (valve seat) ①
  • Needle valve ②
  • Float ③
  • Float pin ④

NOTE:

  • After installing the needle valve to the float, install them to the carburetor.
  • Check the float for smooth movement.

12. Install:

  • Pilot screw ①
  • Spring ②
  • Washer ③
  • O-ring ④

Note the following installation points:

  • Turn in the pilot screw until it is lightly seated.
  • Turn out the pilot screw by the number of turns recorded before removing.

YAMAHA WR250FP - Note the following installation points: - 1

Pilot screw:

2 turns out

* 1 turn out

** 1-1/8 turns out

(example)

* For EUROPE
** For CDN, ZA, AUS and NZ

13. Install:

  • O-ring
  • Leak jet ①
  • Float chamber ②
  • Bolt (float chamber) ③
  • Cable holder (throttle stop screw cable) ④
  • Hose holder (carburetor breather hose) ⑤

10. Monter:

text_image Technical diagram of mechanical assembly with numbered components and directional arrows indicating motion or movement

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram of a mechanical assembly with numbered components and cross-sectional views

YAMAHA WR250FP - Monter: - 2

text_image Technical diagram of a mechanical device with numbered parts for identification

YAMAHA WR250FP - Monter: - 3

text_image Technical diagram showing mechanical assembly with numbered components and a magnified detail view labeled 'a'

YAMAHA WR250FP - Monter: - 4

text_image Technical diagram of a mechanical assembly with numbered components labeled ①, ②, and ③.

14. Install:

• Diaphragm (air cut valve) ①
- Spring (air cut valve) ②
- O-ring ③
- Air cut valve cover ④
- Screw (air cut valve cover) ⑤

15. Install:

• Diaphragm (accelerator pump) ①
- Spring ②
- O-ring ③
- Accelerator pump cover ④
- Bolt (accelerator pump cover) ⑤

NOTE:

Install the diaphragm (accelerator pump) with its mark ⓐ facing the spring.

16. Install:

  • Jet needle ①
  • Collar ②
  • Spring ③
  • Needle holder ④
  • Throttle valve plate ⑤
    To throttle valve ⑥.

17. Install:

  • Throttle valve assembly ①
  • Screw (throttle shaft) ②

NOTE:

Install the valve lever rollers ③ into the slits ④ of the throttle valve.

18. Install:

  • O-ring ①
  • Valve lever housing cover ②
  • Bolt (valve lever housing cover) ③

14. Monter:

text_image Technical diagram of a mechanical component with numbered parts labeled ①

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram of a mechanical device with labeled parts and a magnified inset showing a circular component with dimension 'a'.

YAMAHA WR250FP - Monter: - 2

text_image Technical diagram of a mechanical assembly with numbered components, likely for automotive or automotive maintenance.

YAMAHA WR250FP - Monter: - 3

text_image ① a a ①

YAMAHA WR250FP - Monter: - 4

text_image Technical diagram showing mechanical assembly with labeled parts (a) and (b), including a circular component and a separate close-up of a mechanical component.

19. Install:

- Carburetor breather hose ①

NOTE:

Install the carburetor breather hoses to the carburetor so that the hoses do not bend near where they are installed.

Accelerator pump timing adjustmet

Adjustment steps:

NOTE:

In order for the throttle valve height ⓐ to achieve the specified value, tuck under the throttle valve plate ① the rod ② etc. with the same outer diameter as the specified value.

YAMAHA WR250FP - NOTE: - 1

Throttle valve height: 1.50 mm (0.059 in)

  • Fully turn in the accelerator pump adjusting screw ③.
  • Check that the link lever ④ has free play ⑥ by pushing lightly on it.
  • Gradually turn out the adjusting screw while moving the link lever until it has no more free play.

Carburetor installation

1. Install:

- Clamp ①

NOTE:

Install the projections ⓐ on the carburetor joint between the clamp ends.

2. Install:

- Carburetor joint ①

3 Nm (0.3 m · kg, 2.2 ft · lb)

NOTE:

Install the projection ⓐ on the cylinder head between the carburetor joint slots ⓑ.

19. Monter:

text_image Technical diagram of a mechanical assembly with numbered components and a highlighted section labeled '1'

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram of a mechanical assembly with numbered components and highlighted features

YAMAHA WR250FP - Monter: - 2

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - Monter: - 3

natural_image Technical line drawing of a mechanical assembly with hoses and components (no text or symbols)

YAMAHA WR250FP - Monter: - 4

text_image Technical diagram of a mechanical assembly with labeled parts, including numbered annotations ① and ②.

3. Install:

- Carburetor ①

NOTE:

Install the projection between the carburetor joint slots.

4. Tighten:

- Screw (air filter joint) ①

3 Nm (0.3 m · kg, 2.2 ft · lb)

- Screw (carburetor joint) ②

3 Nm (0.3 m · kg, 2.2 ft · lb)

5. Install:

- Throttle cable cap ①

6. Install:

- Throttle cable ①

7. Adjust:

- Throttle grip free play Refer to "THROTTLE CABLE ADJUSTMENT" section in the CHAPTER 3.

8. Install:

- Throttle cable cover ①

- Screw (throttle cable cover) ②

4 Nm (0.4 m · kg, 2.9 ft · lb)

NOTE:

Install the throttle cable cover with its pawl ⓐ hung on the carburetor.

3. Monter:

- Carburateur ①

N.B.:

text_image Technical diagram of a mechanical assembly with numbered components, likely illustrating a valve or clamp mechanism.

YAMAHA WR250FP - N.B.: - 1

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

9. Install:

  • Throttle position sensor lead coupler ①
  • Clamp ②

Refer to "CABLE ROUTING DIAGRAM" section in the CHAPTER 2.

10. Install:

- Clamp ①

Refer to “CABLE ROUTING DIAGRAM” section in the CHAPTER 2.

9. Monter:

Extent of removal:
① Cylinder head cover removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCYLINDER HEAD COVER REMOVALSeat and fuel tankCarburetorRefer to “SEAT, FUEL TANK AND SIDE COVERS” section.Refer to “CARBURETOR” section.
11Spark plug1
2Cylinder head breather hose1
3Oil tank breather hose1
4Bolt (cylinder head cover)2
5Cylinder head cover1
6Cylinder head cover gasket1
7Timing chain guide (top side)1

ARBRES A CAMES

COUVRE-CULASSE

Extent of removal:
① Camshaft removal

Extent of removalOrderPart nameQ'tyRemarks
CAMSHAFTS REMOVAL
1Timing mark accessing screw1Refer to “REMOVAL POINTS”.
2Crankshaft end accessing screw1
3Timing chain tensioner cap bolt1
4Timing chain tensioner1
5Camshaft cap2
6Clip2
7Exhaust camshaft1
8Intake camshaft1

ARBRES A CAMES

text_image Technical diagram showing mechanical components with numbered labels ① and ②, likely illustrating a gear or cam mechanism.

YAMAHA WR250FP - ARBRES A CAMES - 1

text_image Technical diagram showing mechanical assembly with labeled parts (a) and (b), including a hand operating a rotating component.

YAMAHA WR250FP - ARBRES A CAMES - 2

text_image A B C D

YAMAHA WR250FP - ARBRES A CAMES - 3

text_image Technical diagram showing mechanical assembly with numbered components, likely for repair or maintenance instructions.

YAMAHA WR250FP - ARBRES A CAMES - 4

text_image Technical diagram of an engine cylinder assembly with numbered components and mechanical parts highlighted

REMOVAL POINTS Camshaft

1. Remove:

  • Timing mark accessing screw ①
  • Crankshaft end accessing screw ②

2. Align:

• T.D.C. mark
With align mark.

Checking steps:

- Turn the crankshaft counterclockwise with a wrench.

NOTE:

Squeezing the decompression lever allows the crankshaft to be turned easily.

- Align the T.D.C. mark ⓐ on the rotor with the align mark ⓑ on the crankcase cover when piston is at T.D.C. on compression stroke.

NOTE:

In order to be sure that the piston is at Top Dead Center, the punch mark © on the exhaust camshaft and the punch mark ⓐ on the intake camshaft must align with the cylinder head surface, as shown in the illustration.

3. Remove:

  • Timing chain tensioner cap bolt ①
  • Timing chain tensioner ②
  • Gasket

4. Remove:

  • Bolt (camshaft cap) ①
  • Camshaft cap ②
  • Clip

NOTE:

Remove the bolts (camshaft cap) in a criss-cross pattern, working from the outside in.

CAUTION:

The bolts (camshaft cap) must be removed evenly to prevent damage to the cylinder head, camshafts or camshaft caps.

POINTS DE DEPOSE

Arbre à cames

text_image Technical diagram of an engine cylinder with labeled components and wiring

YAMAHA WR250FP - Arbre à cames - 1

text_image a I1151001

YAMAHA WR250FP - Arbre à cames - 2

text_image b 11151002

5. Remove:

  • Exhaust camshaft ①
  • Intake camshaft ②

NOTE:

Attach a wire ③ to the timing chain to prevent it from falling into the crankcase.

INSPECTION

Camshaft

1. Inspect:

  • Cam lobe
    Pitting/scratches/blue discoloration → Replace.

2. Measure:

  • Cam lobe length ⓐ and ⓑ
    Out of specification → Replace.

YAMAHA WR250FP - Measure: - 1

Cam lobes length:

Intake:

① 30.296 \~ 30.346 mm
(1.1923 \~ 1.1947 in)
: 30.196 mm
(1.1888 in)

(b) 22.45 \~ 22.55 mm

(0.8839 \~ 0.8878 in)

: 22.35 mm

(0.8799 in)

Exhaust:

① 30.399 \~ 30.499 mm
(1.1968 \~ 1.2007 in)
: 30.299 mm
(1.1929 in)

⑥ 22.45 \~ 22.55 mm

(0.8839 \~ 0.8878 in)

: 22.35 mm

(0.8799 in)

YAMAHA WR250FP - Exhaust: - 1

text_image I1151402

3. Measure:

  • Runout (camshaft)
    Out of specification → Replace.

YAMAHA WR250FP - Measure: - 1

Runout (camshaft):

Less than 0.03 mm (0.0012 in)

5. Déposer:

① 30,399 à 30,499 mm (1,1968 à 1,2007 in) :30,299 mm (1,1929 in)

⑥ 22,45 à 22,55 mm (0,8839 à 0,8878 in) :22,35 mm (0,8799 in)

PRÜFUNG

Nockenwelle

1. Kontrollieren:

① 30,399–30,499 mm 30,299 mm ② 22,45–22,55 mm 22,35 mm

ISPEZIONE

Albero a camme

1. Ispezionare:

① 30,296 \~ 30,346 mm (1,1923 \~ 1,1947 in) : 30,196 mm (1,1888 in)

⑥ 22,45 \~ 22,55 mm (0,8839 \~ 0,8878 in) : 22,35 mm (0,8799 in)

Scarico:

① 30,399 \~ 30,499 mm (1,1968 \~ 1,2007 in) : 30,299 mm (1,1929 in)

⑥ 22,45 \~ 22,55 mm (0,8839 \~ 0,8878 in) : 22,35 mm (0,8799 in)

3. Mesurer:

- Camshaft-to-cap clearance

Out of specification → Measure bearing diameter (camshaft).

YAMAHA WR250FP - Mesurer: - 1

Camshaft-to-cap clearance:

0.020 \~ 0.054 mm

(0.0008 \~ 0.0021 in)

: 0.08 mm (0.003 in)

YAMAHA WR250FP - Mesurer: - 2

text_image Technical diagram of a vehicle engine component with labeled parts and numbered annotation

YAMAHA WR250FP - Mesurer: - 3

text_image Technical diagram of a mechanical assembly with numbered component labels

YAMAHA WR250FP - Mesurer: - 4

text_image a I1151003

YAMAHA WR250FP - Mesurer: - 5

natural_image Technical line drawing of two mechanical gears with a labeled connection point (no text or symbols beyond the number 1)

Measurement steps:

  • Install the camshaft onto the cylinder head.
  • Position a strip of Plastigauge® ① onto the camshaft.
  • Install the clip, dowel pins and camshaft caps.

YAMAHA WR250FP - Measurement steps: - 1

Bolt (camshaft cap): 10 Nm (1.0 m • kg, 7.2 ft • lb)

NOTE:

  • Tighten the bolts (camshaft cap) in a criss-cross pattern from innermost to outer caps.
  • Do not turn the camshaft when measuring clearance with the Plastigauge®.
  • Remove the camshaft caps and measure the width of the Plastigauge® ①.

5. Measure:

  • Camshaft outside diameter ⓐ
    Out of specification → Replace the camshaft.
    Within specification → Replace camshaft case and camshaft caps as a set.

YAMAHA WR250FP - Measure: - 1

Camshaft outside diameter:

21.967 \~ 21.980 mm

(0.8648 \~ 0.8654 in)

Camshaft sprocket

1. Inspect:

  • Camshaft sprocket ①
    Wear/damage → Replace the camshaft assembly and timing chain as a set.

4. Mesurer:

natural_image Illustration of a hand holding a mechanical component with a tool, showing a curved arrow and numbered label (1), no text or symbols present.

YAMAHA WR250FP - Mesurer: - 1

natural_image Line drawing of a hand holding a mechanical component with a screwdriver, no text or symbols present

YAMAHA WR250FP - Mesurer: - 2

text_image Technical diagram of a mechanical assembly with labeled parts, including a motor component and numbered callouts.

YAMAHA WR250FP - Mesurer: - 3

text_image Technical diagram of a mechanical assembly with labeled parts and directional arrows indicating motion or movement.

YAMAHA WR250FP - Mesurer: - 4

text_image C ③ d

Timing chain tensioner

1. Check:

  • While pressing the tensioner rod lightly with fingers, use a thin screwdriver ① and wind the tensioner rod up fully clockwise.
  • When releasing the screwdriver by pressing lightly with fingers, make sure that the tensioner rod will come out smoothly.
  • If not, replace the tensioner assembly.

ASSEMBLY AND INSTALLATION

Camshaft

1. Install:

  • Exhaust camshaft ①
  • Intake camshaft ②

Installation steps:

- Turn the crankshaft counterclockwise with a wrench.

NOTE:

Squeezing the decompression lever allows the crankshaft to be turned easily.

  • Align the T.D.C. mark ⓐ on the rotor with the align mark ⓑ on the crankcase cover when piston is at T.D.C. on compression stroke.
  • Fit the timing chain ③ onto both camshaft sprockets and install the camshafts on the cylinder head.

NOTE:

The camshafts should be installed onto the cylinder head so that the punch mark © on the exhaust camshaft and the punch mark ⓐ on the intake camshaft must align with the cylinder head surface, as shown in the illustration.

text_image Technical diagram of an engine cylinder with labeled components and a fuel injector

CAUTION:

Do not turn the crankshaft during the camshaft installation. Damage or improper valve timing will result.

- Install the clips, camshaft caps ④ and bolts (camshaft cap) ⑤.

YAMAHA WR250FP - CAUTION: - 1

Bolt (camshaft cap): 10 Nm (1.0 m • kg, 7.2 ft • lb)

NOTE:

  • Before removing the clips, cover the cylinder head with a clean rag to prevent the clips from into the cylinder head cavity.
  • Apply the engine oil on the thread and contact surface of the bolts (camshaft cap).
  • Tighten the bolts (camshaft cap) ⑤ in a crisscross pattern.

CAUTION:

The bolts (camshaft cap) must be tightened evenly, or damage to the cylinder head, camshaft caps, and camshaft will result.

YAMAHA WR250FP - CAUTION: - 1

natural_image Illustration of a hand holding a mechanical component with an arrow indicating direction (no text or symbols present)

YAMAHA WR250FP - CAUTION: - 2

text_image New ① a ③ ② ③

2. Install:

- Timing chain tensioner

Installation steps:

  • While pressing the tensioner rod lightly with fingers, use a thin screwdriver and wind the tensioner rod up fully clockwise.
  • With the rod fully wound and the chain tensioner UP mark ⓐ facing upward, install the gasket ① and the timing chain tensioner ②, and tighten the bolt ③ to the specified torque.

YAMAHA WR250FP - Installation steps: - 1

Bolt (timing chain tensioner): 10 Nm (1.0 m • kg, 7.2 ft • lb)

ATTENTION:

- Release the screwdriver, check the tensioner rod to come out and tighten the gasket ④ and the cap bolt ⑤ to the specified torque.

YAMAHA WR250FP - ATTENTION: - 1

Tensioner cap bolt: 7 Nm (0.7 m • kg, 5.1 ft • lb)

3. Turn:

- Crankshaft Counterclockwise several turns

4. Check:

  • Rotor T.D.C. mark Align with the crankcase align mark.
  • Camshaft match marks Align with the cylinder head surface. Out of alignment → Adjust.

YAMAHA WR250FP - Check: - 1

text_image Technical diagram showing mechanical components with numbered labels ① and ②, likely illustrating a gear or pulley system.

5. Install:

  • Timing mark accessing screw ①
  • Crankshaft end accessing screw ②

YAMAHA WR250FP - Install: - 1

text_image Technical diagram showing exploded view of mechanical assembly with numbered components and a close-up of a tool.

6. Install:

  • Timing chain guide (top side) ①
  • Cylinder head cover gasket ②
  • Cylinder head cover ③
  • Bolt (cylinder head cover) ④

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Apply the sealant on the cylinder head cover gasket.

YAMAHA WR250FP - NOTE: - 1

natural_image Technical line drawing of a mechanical component with no visible text or symbols

YAMAHA WR250FP - NOTE: - 2

Quick gasket®: ACC-QUICK-GS-KT YAMAHA Bond No. 1215: 90890-85505

  • Oil tank breather hose
  • Cylinder head breather hose
  • Spark plug

13 Nm (1.3 m · kg, 9.4 ft · lb)

7. Monter:

Extent of removal:
① Cylinder head removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCYLINDER HEAD REMOVALSeat and fuel tankExhaust pipe and silencerRadiator hose 1CarburetorCamshaftUpper engine bracketRefer to “SEAT, FUEL TANK AND SIDE COVERS” section.Refer to “EXHAUST PIPE AND SILENCER” section.Disconnect at cylinder head side.Refer to “CARBURETOR” section.Refer to “CAMSHAFTS” section.Refer to “ENGINE REMOVAL” section.
11Radiator pipe1Disconnect the decompression cable.
2Decompression cable guide1
3Oil delivery pipe1
4Nut2
5Bolt [L=135 mm (5.31 in)]2
6Bolt [L=145 mm (5.71 in)]2
7Cylinder head1
8Timing chain guard (exhaust side)1
9Bolt (decompression shaft)1
10Decompression shaft1

CULASSE

YAMAHA WR250FP - CULASSE - 1

natural_image Technical line drawing of an internal combustion engine cylinder with a tool inserted (no text or labels)

YAMAHA WR250FP - CULASSE - 2

natural_image Technical line drawing of an internal combustion engine cylinder (no text or labels)

INSPECTION

Cylinder head

1. Eliminate:

- Carbon deposits (from the combustion chambers) Use a rounded scraper.

NOTE:

Do not use a sharp instrument to avoid damaging or scratching:

  • Spark plug threads
  • Valve seats

2. Inspect:

- Cylinder head Scratches/damage → Replace.

3. Measure:

- Cylinder head warpage Out of specification → Resurface.

YAMAHA WR250FP - Measure: - 1

Cylinder head warpage: Less than 0.05 mm (0.002 in)

Warpage measurement and resurface-ment steps:

  • Place a straightedge and a feeler gauge across the cylinder head.
  • Use a feeler gauge to measure the warpage.
  • If the warpage is out of specification, resurface the cylinder head.
  • Place a 400 \~ 600 grit wet sandpaper on the surface plate, and resurface the head using a figure-eight sanding pattern.

NOTE:

To ensure an even surface rotate the cylinder head several times.

CONTROLE

Culasse

  1. Eliminer:
text_image E ③ ② New

ASSEMBLY AND INSTALLATION Cylinder head

1. Install:

  • Decompression shaft ①
    • Copper washer ② New
  • Bolt (decompression shaft) ③

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Apply the engine oil on the decompression shaft.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components and a label 'New' in the corner.

2. Install:

  • Dowel pin ①
  • Cylinder head gasket ② New
  • Timing chain guide (exhaust side) ③
  • Decompression cable ④
  • Cylinder head ⑤

NOTE:

  • Install the decompression cable to the cylinder head, and then to the cylinder.
  • While pulling up the timing chain, install the timing chain guide (exhaust side) and cylinder head.

ASSEMBLAGE ET MONTAGE

Culasse

text_image ① ② ③ ④ ⑤

YAMAHA WR250FP - Culasse - 1

text_image 1 2 3 4 5 6

YAMAHA WR250FP - Culasse - 2

text_image New ① ② ③ ④

YAMAHA WR250FP - Culasse - 3

text_image Technical diagram showing mechanical assembly with labeled parts 1 and 2

YAMAHA WR250FP - Culasse - 4

text_image Technical diagram showing mechanical assembly with numbered components and labeled parts

3. Install:

  • Washer ①
  • Cable guide ②
  • Bolts [L=145 mm (5.71 in)] ③

$$ \boxed { \begin{array}{l} \text { 38 Nm (3.8 m \cdot kg, 27 ft \cdot lb) } \end{array} } $$

- Bolts [L=135 mm (5.31 in)] ④

$$ \boxed { \begin{array}{l} \text { 38 Nm (3.8 m \cdot kg, 27 ft \cdot lb) } \end{array} } $$

• Nuts ⑤ 10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

  • Apply the molybdenum disulfide grease on the thread and contact surface of the bolts.
  • Follow the numerical order shown in the illustration. Tighten the bolts and nuts in two stages.

4. Install:

• Copper washer ① New
- Oil delivery pipe ②
- Union bolt (M8) ③

$$ \boxed { \begin{array}{l} \text { 18 Nm (1.8 m \cdot kg, 13 ft \cdot lb) } \end{array} } $$

- Union bolt (M10) ④

$$ \boxed { \begin{array}{l l} \text { ♡ } & 2 0 \mathrm{Nm} (2. 0 \mathrm{m} \cdot \mathrm{kg}, 1 4 \mathrm{ft} \cdot \mathrm{lb}) \end{array} } $$

5. Install:

  • Decompression cable guide ①
  • Bolt (decompression cable guide) ②

$$ 1 0 \mathrm{Nm} (1. 0 \mathrm{m} \cdot \mathrm{kg}, 7. 2 \mathrm{ft} \cdot \mathrm{lb}) $$

6. Install:

  • Radiator pipe ①
  • Bolt (radiator pipe) ②

$$ \text { } \boxed {\text { }} 1 0 \mathrm{Nm} (1. 0 \mathrm{m} \cdot \mathrm{kg}, 7. 2 \mathrm{ft} \cdot \mathrm{lb}) $$

3. Monter:

text_image 1 2 3 4 5 6 7 New New 8 9 M M

Extent of removal:
① Valve removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalVALVES AND VALVE SPRINGS REMOVALCylinder headRefer to “CYLINDER HEAD” section.
11Valve lifter5Use special tool.Refer to “REMOVAL POINTS”.
2Adjusting pad5
3Valve cotter10
4Valve spring retainer5
5Valve spring5
6Valve stem seal5
7Valve spring seat5
8Exhaust valve2
9Intake valve3

SOUPAPES ET RESSORTS DE SOUPAPE

text_image EX IN ① ②

YAMAHA WR250FP - SOUPAPES ET RESSORTS DE SOUPAPE - 1

text_image Technical diagram of a mechanical assembly with numbered components, likely illustrating a valve or actuator mechanism.

YAMAHA WR250FP - SOUPAPES ET RESSORTS DE SOUPAPE - 2

text_image ① I1171201

REMOVAL POINTS

Valve lifter and valve cotter

1. Remove:

  • Valve lifter ①
  • Pad ②

NOTE:

Identify each lifter ① and pad ② position very carefully so that they can be reinstalled in their original place.

2. Check:

- Valve sealing

Leakage at the valve seat → Inspect the valve face, valve seat and valve seat width.

Checking steps:

  • Pour a clean solvent ① into the intake and exhaust ports.
  • Check that the valve seals properly.
    There should be no leakage at the valve seat ②.

3. Remove:

- Valve cotter

NOTE:

Attach a valve spring compressor ① between the valve spring retainer and the cylinder head to remove the valve cotters.

YAMAHA WR250FP - NOTE: - 1

Valve spring compressor: YM-4019/90890-04019

SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE

ENG

YAMAHA WR250FP - SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE - 1

POINTS DE DEPOSE

text_image Technical diagram showing a mechanical assembly with labeled component '1'

YAMAHA WR250FP - POINTS DE DEPOSE - 1

text_image Technical diagram showing mechanical assembly with labeled parts ① and ②, likely illustrating a robotic or mechanical assembly.

YAMAHA WR250FP - POINTS DE DEPOSE - 2

text_image ③ I1170601

INSPECTION

Valve

  1. Measure:

- Stem-to-guide clearance

Stem-to-guide clearance = valve guide inside diameter ① - valve stem diameter ②

Out of specification → Replace the valve guide.

YAMAHA WR250FP - Valve - 1

Clearance (stem to guide):

Intake:

0.010 \~ 0.037 mm

(0.0004 \~ 0.0015 in)

: 0.08 mm (0.003 in)

Exhaust:

0.025 \~ 0.052 mm

(0.0010 \~ 0.0020 in)

: 0.10 mm (0.004 in)

  1. Replace:

- Valve guide

Replacement steps:

NOTE:

To ease guide removal, installation and to maintain correct fit heat the cylinder head in an over to 100 °C ( 212 °F ).

  • Remove the valve guide using a valve guide remover ①.
  • Install the new valve guide using a valve guide remover ① and valve guide installer ②.

After installing the valve guide, bore the valve guide using a valve guide reamer ③ to obtain proper stem-to-guide clearance.

CONTROLE

Soupape

  1. Mesurer:

Intake 4.0 mm (0.16 in)

YM-4111/90890-04111

Exhaust 4.5 mm (0.18 in)

YM-4116/90890-04116

Valve guide installer:

Intake 4.0 mm (0.16 in)

YM-4112/90890-04112

Exhaust 4.5 mm (0.18 in)

YM-4117/90890-04117

Valve guide reamer:

Intake 4.0 mm (0.16 in)

YM-4113/90890-04113

Exhaust 4.5 mm (0.18 in)

YM-4118/90890-04118

NOTE:

After replacing the valve guide reface the valve seat.

3. Inspect:

- Valve face

Pitting/wear → Grind the face.

- Valve stem end

Mushroom shape or diameter larger than the body of the stem → Replace.

YAMAHA WR250FP - Inspect: - 1

text_image a 45°

4. Measure:

- Margin thickness ⓐ

Out of specification → Replace.

YAMAHA WR250FP - Measure: - 1

Margin thickness:

Intake:

0.8 mm (0.0315 in)

Exhaust:

0.7 mm (0.0276 in)

YAMAHA WR250FP - Measure: - 2

Admission 4,0 mm (0,16 in)

YM-4111/90890-04111

Echappement 4,5 mm

(0,18 in)

YM-4116/90890-04116

Admission 4,0 mm (0,16 in)

YM-4112/90890-04112

Echappement 4,5 mm

(0,18 in)

YM-4117/90890-04117

Admission 4,0 mm (0,16 in)

YM-4113/90890-04113

Echappement 4,5 mm

(0,18 in)

YM-4118/90890-04118

N.B.:

Out of specification → Replace.

YAMAHA WR250FP - Measure: - 3

Runout limit: 0.01 mm (0.0004 in)

NOTE:

  • When installing a new valve always replace the guide.
  • If the valve is removed or replaced always replace the oil seal.

6. Eliminate:

  • Carbon deposits
    (from the valve face and valve seat)

7. Inspect:

  • Valve seat
    Pitting/wear → Reface the valve seat.

YAMAHA WR250FP - Inspect: - 1

text_image I1171603

8. Measure:

  • Valve seat width ⓐ
    Out of specification → Reface the valve seat.

YAMAHA WR250FP - Measure: - 1

natural_image Simple line drawing of a circular object with a labeled point 'b' and vertical line, no text or symbols present.

YAMAHA WR250FP - Measure: - 2

Valve seat width:

Intake:

0.9 \~ 1.1 mm (0.0354 \~ 0.0433 in)

: 1.6 mm (0.0630 in)

Exhaust:

0.9 \~ 1.1 mm (0.0354 \~ 0.0433 in)

: 1.6 mm (0.0630 in)

Measurement steps:

  • Apply Mechanic's blueing dye (Dykem) ⑥ to the valve face.
    • Install the valve into the cylinder head.
  • Press the valve through the valve guide and onto the valve seat to make a clear pattern.
  • Measure the valve seat width. Where the valve seat and valve face made contact, blueing will have been removed.
  • If the valve seat is too wide, too narrow, or the seat is not centered, the valve seat must be refaced.

SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE

ENG

YAMAHA WR250FP - SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE - 1

5. Mesurer:

After refacing the valve seat or replacing the valve and valve guide, the valve seat and valve face should be lapped.

YAMAHA WR250FP - Mesurer: - 1

natural_image Simple line drawing of a circular object with two vertical lines above it, no text or symbols present.

YAMAHA WR250FP - Mesurer: - 2

natural_image Simple line drawing of a vertical tube with a labeled arrow pointing to the tip (no text or symbols present)

YAMAHA WR250FP - Mesurer: - 3

natural_image Technical line drawing of a mechanical assembly with rotating components and circular base (no text or symbols)

Lapping steps:

- Apply a coarse lapping compound to the valve face.

CAUTION:

Do not let the compound enter the gap between the valve stem and the guide.

  • Apply molybdenum disulfide oil to the valve stem.
    • Install the valve into the cylinder head.
  • Turn the valve until the valve face and valve seat are evenly polished, then clean off all of the compound.

NOTE:

For best lapping results, lightly tap the valve seat while rotating the valve back and forth between your hands.

- Apply a fine lapping compound to the valve face and repeat the above steps.

NOTE:

After every lapping operation be sure to clean off all of the compound from the valve face and valve seat.

  • Apply Mechanic's blueing dye (Dykem) to the valve face.
    • Install the valve into the cylinder head.
  • Press the valve through the valve guide and onto the valve seat to make a clear pattern.
  • Measure the valve seat width again. If the valve seat width is out of specification, reface and relap the valve seat.

  • Roder:

  • Face de soupape

  • Siège de soupape

N.B.:

text_image I1171902 (a)

YAMAHA WR250FP - NOTE: - 1

text_image I1171904

Valve spring

1. Measure:

- Valve spring free length ⓐ

Out of specification → Replace.

YAMAHA WR250FP - Measure: - 1

Free length (valve spring):

Intake:

37.81 mm (1.49 in)

: 35.9 mm (1.41 in)

Exhaust:

37.54 mm (1.48 in)

: 35.7 mm (1.41 in)

2. Measure:

- Compressed spring force ⓐ

Out of specification → Replace.

⑥ Installed length

YAMAHA WR250FP - Measure: - 1

Compressed spring force:

Intake:

10.1 \~ 11.6 kg at 29.13 mm

(22.27 \~ 25.57 lb at 1.15 in)

Exhaust:

12.9 \~ 14.7 kg at 29.30 mm

(28.44 \~ 32.41 lb at 1.15 in)

YAMAHA WR250FP - Measure: - 2

text_image a

YAMAHA WR250FP - Measure: - 3

natural_image Simple line drawing of a cylinder (no text or symbols on the shape itself)

3. Measure:

- Spring tilt ⓐ

Out of specification → Replace.

YAMAHA WR250FP - Measure: - 1

Spring tilt limit:

Intake:

2.5°/1.7 mm (0.067 in)

Exhaust:

2.5°/1.6 mm (0.063 in)

Valve lifter

1. Inspect:

- Valve lifter

Scratches/damage → Replace both lifters and cylinder head.

Ressort de soupape

1. Mesurer:

text_image Technical diagram showing cross-sectional and top views of a mechanical component with labeled parts (a) and (b)

Combination of cylinder head and valve lifter

1. Combination:

For this combination, match the paint color on the cylinder head with that on the valve lifter according to the chart below.

Combination
Cylinder head mark ⓐ (color)Valve lifter mark ⓑ (color)
RedRed
BlueBlue
YellowYellow
PurpleBlack

NOTE:

When you purchase a cylinder head, you cannot designate its size. Choose the valve lifter that matches the above chart.

ASSEMBLY AND INSTALLATION

Valve and valve spring

1. Apply:

- Molybdenum disulfide oil Onto the valve stem and valve stem seal.

YAMAHA WR250FP - Apply: - 1

text_image a b b

2. Install:

  • Valve ①
  • Valve spring seat ②
  • Valve stem seal ③
  • Valve spring ④
  • Valve spring retainer ⑤
    To cylinder head.

YAMAHA WR250FP - Install: - 1

flowchart
graph TD
    A["1"] --> B["2"]
    C["3"] --> D["4"]
    E["5"] --> F["6"]
    G["7"] --> H["8"]
    I["9"] --> J["10"]
    K["11"] --> L["12"]
    M["M"] --> N["End"]

NOTE:

- Make sure that each valve is installed in its original place, also referring to the painted color as follows.

Intake (middle) ⓐ: yellow

Intake (right/left) ⓑ: white

Exhaust: no paint

- Install the valve springs with the larger pitch © facing upward.

d Smaller pitch

SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE

natural_image Line drawing of a hand using a tool to inspect or install an internal mechanical component (no text or symbols present)

YAMAHA WR250FP - SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE - 1

text_image Technical diagram of a mechanical assembly with labeled parts and numbered annotations

3. Install:

- Valve cotter

NOTE:

While compressing the valve spring with a valve spring compressor ① install the valve cotters.

YAMAHA WR250FP - NOTE: - 1

Valve spring compressor: YM-4019/90890-04019

  1. To secure the valve cotters onto the valve stem, lightly tap the valve tip with a piece of wood.

CAUTION:

Hitting the valve tip with excessive force could damage the valve.

5. Install:

  • Adjusting pad ①
  • Valve lifter ②

NOTE:

  • Apply the molybdenum disulfied oil on the valve stem end.
  • Apply the engine oil on the valve lifters.
  • Valve lifter must turn smoothly when rotated with a finger.
  • Be careful to reinstall valve lifters and pads in their original place.

SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE

ENG

YAMAHA WR250FP - SOUPAPES ET RESSORTS DE SOUPAPE VENTILE UND VENTILFEDERN VALVOLE E MOLLE VALVOLE - 1

3. Monter:

- Clavette de soupape

N.B.:

Extent of removal:
① Cylinder removal
② Piston removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCYLINDER AND PISTON REMOVALCylinder headRefer to “CYLINDER HEAD” section.
[48x42]1Bolt (cylinder)1Use special tool.Refer to “REMOVAL POINTS”.
2Cylinder1
3Piston pin clip2
4Piston pin1
5Piston1
6Piston ring set1

CYLINDRE ET PISTON

natural_image Technical line drawing of a piston assembly with labeled component (no text or symbols beyond label)

YAMAHA WR250FP - CYLINDRE ET PISTON - 1

text_image ③ ② ④ 11221001

YAMAHA WR250FP - CYLINDRE ET PISTON - 2

natural_image Line drawing of a hand holding a circular ring, with a numbered label pointing to the ring (no text or symbols beyond the number)

YAMAHA WR250FP - CYLINDRE ET PISTON - 3

text_image D₁ D₂ D₃ D₄ D₅ D₆ I1210102

REMOVAL POINTS

Piston and piston ring

1. Remove:

  • Piston pin clip ①
  • Piston pin ②
  • Piston ③

NOTE:

  • Put identification marks on each piston head for reference during reinstallation.
  • Before removing each piston pin, deburr the clip groove and pin hole area. If the piston pin groove is deburred and the piston pin is still difficult to remove, use the piston pin puller set ④.

YAMAHA WR250FP - NOTE: - 1

Piston pin puller set: YU-1304/90890-01304

CAUTION:

Do not use a hammer to drive the piston pin out.

2. Remove:

- Piston ring ①

NOTE:

Spread the end gaps apart while at the same time lifting the piston ring over the top of the piston crown, as shown in the illustration.

INSPECTION

Cylinder and piston

1. Inspect:

- Cylinder and piston walls Vertical scratches → Replace cylinder and piston.

2. Measure:

- Piston-to-cylinder clearance

Measurement steps:

1st step:

- Measure the cylinder bore "C" with a cylinder bore gauge.

NOTE:

Measure the cylinder bore “C” in parallel to and at right angles to the crankshaft. Then, find the average of the measurements.

POINTS DE DEPOSE

Cylinder bore “C”77.00 ~ 77.01 mm(3.0315 ~ 3.0319 in)
Taper limit “T”0.05 mm (0.002 in)
Out of round “R”0.05 mm (0.002 in)
“C” = Maximum D
“T” = (Maximum D1 or D2)- (Maximum D5 or D6)
“R” = (Maximum D1, D3 or D5)- (Minimum D2, D4 or D6)
·If out of specification, replace the cylinder,and replace the piston and piston rings as set.2nd step:·Measure the piston skirt diameter “P” witha micrometer.@ 8 mm (0.31 in) from the piston bottom edge
Piston size “P”
Standard76.955 ~ 76.970 mm(3.0297 ~ 3.0303 in)
·If out of specification, replace the pistonand piston rings as a set.3rd step:·Calculate the piston-to-cylinder clearancewith following formula:
Piston-to-cylinder clearance =Cylinder bore “C” -Piston skirt diameter “P”
[Piston-to-cylinder clearance:0.040 ~ 0.065 mm(0.0016 ~ 0.0026 in): 0.1 mm (0.004 in)
·If out of specification, replace the cylinder,and replace the piston and piston rings as set.
natural_image Line drawing of two hands holding a circular object with a numbered label (1) on the top part, no text or symbols present.

YAMAHA WR250FP - POINTS DE DEPOSE - 1

text_image I1221401

Piston ring

1. Measure:

- Ring side clearance Use a feeler gauge ①.

Out of specification → Replace the piston and rings as a set.

NOTE:

Clean carbon from the piston ring grooves and rings before measuring the side clearance.

Side clearance:
Standard
Top ring0.030 ~ 0.065 mm(0.0012 ~ 0.0026 in)0.12 mm(0.005 in)
2nd ring0.020 ~ 0.055 mm(0.0008 ~ 0.0022 in)0.12 mm(0.005 in)

2. Position:

- Piston ring (in cylinder)

NOTE:

Insert a ring into the cylinder and push it approximately 10 mm (0.39 in) into the cylinder. Push the ring with the piston crown so that the ring will be at a right angle to the cylinder bore.

(a) 10 mm (0.39 in)

3. Measure:

- Ring end gap

Out of specification → Replace.

NOTE:

You cannot measure the end gap on the expander spacer of the oil control ring. If the oil control ring rails show excessive gap, replace all three rings.

YAMAHA WR250FP - NOTE: - 1End gap:
Standard
Top ring0.15 ~ 0.25 mm(0.006 ~ 0.010 in)0.50 mm(0.020 in)
2nd ring0.30 ~ 0.45 mm(0.012 ~ 0.018 in)0.80 mm(0.031 in)
Oil ring0.10 ~ 0.40 mm(0.004 ~ 0.016 in)

Segment de piston

1. Mesurer:

text_image Technical diagram showing a hand using a micrometer to measure a tool, labeled with 'a' indicating measurement point.

YAMAHA WR250FP - Mesurer: - 1

text_image b

YAMAHA WR250FP - Mesurer: - 2

text_image UP E

Piston pin

1. Inspect:

- Piston pin Blue discoloration/grooves → Replace, then inspect the lubrication system.

2. Measure:

- Piston pin-to-piston clearance

Measurement steps:

- Measure the outside diameter (piston pin) ①. If out of specification, replace the piston pin.

YAMAHA WR250FP - Measurement steps: - 1

Outside diameter (piston pin): 15.991 \~ 16.000 mm (0.6296 \~ 0.6299 in)

- Measure the inside diameter (piston) ⑥.

YAMAHA WR250FP - Measurement steps: - 2

Inside diameter (piston): 16.002 \~ 16.013 mm (0.6300 \~ 0.6304 in)

- Calculate the piston pin-to-piston clearance with the following formula.

Piston pin-to-piston clearance = Inside diameter (piston) ⓑ - Outside diameter (piston pin) ⓐ

- If out of specification, replace the piston.

YAMAHA WR250FP - Measurement steps: - 3

Piston pin-to-piston clearance: 0.002 \~ 0.022 mm (0.0001 \~ 0.0009 in) : 0.07 mm (0.003 in)

ASSEMBLY AND INSTALLATION Piston ring and piston

1. Install:

- Piston ring Onto the piston.

NOTE:

  • Be sure to install the piston rings so that the manufacturer's marks or numbers are located on the upper side of the rings.
  • Lubricate the piston and piston rings liberally with engine oil.

Axe de piston

1. Contrôler:

- Axe de piston

text_image ① ② ③ New E

YAMAHA WR250FP - Contrôler: - 1

text_image ③ New

2. Position:

  • Top ring
  • 2nd ring
  • Oil ring

Offset the piston ring end gaps as shown.

① Top ring end
⑥ 2nd ring end
© Oil ring end (upper)
d Oil ring
© Oil ring end (lower)

3. Install:

  • Piston ①
  • Piston pin ②
  • Piston pin clip ③

New

NOTE:

  • Apply engine oil onto the piston pin and piston.
  • Be sure that the arrow mark ⓐ on the piston points to the exhaust side of the engine.
  • Before installing the piston pin clip, cover the crankcase with a clean rag to prevent the piston pin clip from falling into the crankcase.
  • Install the piston pin clips with their ends facing downward.

Cylinder

1. Lubricate:

  • Piston
  • Piston ring
  • Cylinder

NOTE:

Apply a liberal coating of engine oil.

YAMAHA WR250FP - NOTE: - 1

text_image New ① ② ① ② C B

2. Install:

  • Dowel pin ①
  • O-ring ② New

NOTE:

Apply the lithium soap base grease on the O-ring.

2. Positionner:

text_image ① ② ③ ④ ⑤ New

3. Install:

  • Cylinder gasket ①
  • Cylinder ②

New

NOTE:

Install the cylinder with one hand while compressing the piston rings with the other hand.

CAUTION:

  • Pass the timing chain ③ through the timing chain cavity.
  • Be careful not to damage the timing chain guide ④ during installation.

4. Install:

- Bolt (cylinder) ⑤

10 Nm (1.0 m · kg, 7.2 ft · lb)

3. Monter:

- Joint de cylindre ①

YAMAHA WR250FP - Monter: - 1

- Cylindre ②

N.B.:

① Push rod 1, 2 and push lever shaft removal

③ Friction plate and clutch plate removal

② Push pod 1 disassembly

④ Primary driven gear removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCLUTCH REMOVALDrain the engine oil.Brake pedalClutch cableRefer to “ENGINE OIL REPLACEMENT” section in the CHAPTER 3.Refer to “ENGINE REMOVAL” section.Disconnect at engine side.
YAMAHA WR250FP - N.B.: - 11Clutch cover1
2Clutch spring5
3Pressure plate1
4Push rod 11
5Circlip1
6Washer1
7Bearing1
8Ball1
9Push rod 21

EMBRAYAGE

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - EMBRAYAGE - 1

natural_image Line drawing of a pair of metal tools or pliers (no text or symbols)

YAMAHA WR250FP - EMBRAYAGE - 2

natural_image Technical line drawing of a mechanical clamp or bracket (no text or symbols)

YAMAHA WR250FP - EMBRAYAGE - 3

text_image Technical diagram of a gear assembly with labeled component 1

YAMAHA WR250FP - EMBRAYAGE - 4

text_image Technical diagram showing gear meshing and gear assembly with labeled component ②

YAMAHA WR250FP - EMBRAYAGE - 5

natural_image Illustration of hands assembling a mechanical component with arrows indicating motion (no text or symbols)

YAMAHA WR250FP - EMBRAYAGE - 6

natural_image Line drawing of a hand using a caliper to measure a spring (no text or symbols present)

EC4A3000

REMOVAL POINTS

Clutch boss

  1. Remove:

  2. Nut ①

  3. Lock washer ②
  4. Clutch boss ③

NOTE:

Straighten the lock washer tab and use the clutch holding tool ④ to hold the clutch boss.

YAMAHA WR250FP - Clutch boss - 1

Clutch holding tool: YM-91042/90890-04086

A For USA and CDN
B Except for USA and CDN

EC4A4000

INSPECTION

EC484100

Clutch housing and boss

  1. Inspect:

  2. Clutch housing ①
    Cracks/wear/damage → Replace.

  3. Clutch boss ②
    Scoring/wear/damage → Replace.

EC484201

Primary driven gear

  1. Check:

  2. Circumferential play
    Free play exists → Replace.

  3. Gear teeth ⓐ
    Wear/damage → Replace.

Clutch spring

  1. Measure:

  2. Clutch spring free length ⓐ
    Out of specification → Replace springs as a set.

YAMAHA WR250FP - Clutch spring - 1

Clutch spring free length:

37.0 mm (1.46 in)

: 36.0 mm (1.42 in)

POINTS DE DEPOSE

Noix d'embrayage

37,0 mm (1,46 in) : 36,0 mm (1,42 in)

Kupplungsfeder

37,0 mm (1,46 in) : 36,0 mm (1,42 in)

YAMAHA WR250FP - Kupplungsfeder - 1

natural_image Line drawing of hands using a tool to cut a gear component (no text or symbols)

YAMAHA WR250FP - Kupplungsfeder - 2

text_image ① ② I1411901

Friction plate

1. Measure:

  • Friction plate thickness
    Out of specification → Replace friction plate as a set.
    Measure at all four points.

YAMAHA WR250FP - Measure: - 1

Friction plate thickness:

2.9 \~ 3.1 mm

(0.114 \~ 0.122 in)

: 2.7 mm (0.106 in)

EC484600

Clutch plate

1. Measure:

  • Clutch plate warpage
    Out of specification → Replace clutch plate as a set.
    Use a surface plate ① and thickness gauge ②.

YAMAHA WR250FP - Measure: - 1

Warp limit:

0.1 mm (0.004 in)

YAMAHA WR250FP - Warp limit: - 1

natural_image Technical line drawing of a mechanical lever component with labeled part (1), no text or symbols present

YAMAHA WR250FP - Warp limit: - 2

text_image Exploded view diagram of a mechanical component with numbered parts for identification

Push lever shaft

1. Inspect:

  • Push lever shaft ①
    Wear/damage → Replace.

Push rod

1. Inspect:

- Push rod 1 ①

- Bearing ②

- Washer ③

- Push rod 2 ④

- Ball ⑤

Wear/damage/bend → Replace.

Disque de friction

  1. Mesurer:
text_image Technical diagram illustrating mechanical assembly steps with labeled components and a close-up of the main component.

EC4A5000

ASSEMBLY AND INSTALLATION

Push lever shaft

  1. Install:

  2. Push lever shaft ①

  3. Bolt (push lever shaft) ②

YAMAHA WR250FP - Push lever shaft - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

  • Apply the lithium soap base grease on the oil seal lip.
  • Apply the engine oil on the push lever shaft.
  • Fit the seat plate ③ in the groove ⓐ of the push lever shaft and tighten the bolt (seat plate).

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

Clutch

  1. Install:

• Primary driven gear ①
- Thrust washer ②
- Clutch boss ③

NOTE:

Apply the engine oil on the primary driven gear inner circumference.

YAMAHA WR250FP - NOTE: - 1

text_image ① New ② ③
  1. Install:

- Lock washer ①

YAMAHA WR250FP - NOTE: - 2

- Nut (clutch boss) ②

YAMAHA WR250FP - NOTE: - 3

60 Nm (6.0 m · kg, 43 ft · lb)

NOTE:

Use the clutch holding tool ③ to hold the clutch boss.

YAMAHA WR250FP - NOTE: - 1

natural_image Two technical line drawings of metal clamps labeled A and B, showing different angles and mounting brackets (no text or symbols present)

YAMAHA WR250FP - NOTE: - 2

Clutch holding tool: YM-91042/90890-04086

A For USA and CDN
B Except for USA and CDN

ASSEMBLAGE ET MONTAGE

Levier de poussée

natural_image Technical line drawing of a mechanical gear assembly (no text or symbols)

YAMAHA WR250FP - Levier de poussée - 1

text_image Technical diagram of a mechanical assembly with labeled parts and an inset showing component details

YAMAHA WR250FP - Levier de poussée - 2

text_image Technical diagram illustrating mechanical assembly with labeled parts and a bottle labeled 'E'

YAMAHA WR250FP - Levier de poussée - 3

text_image Technical diagram showing two cross-sectional views of a curved mechanical component with labeled parts ① and ③.

YAMAHA WR250FP - Levier de poussée - 4

text_image New ③ ② ① ④ E
  1. Bend the lock washer ① tab.

  2. Install:

  3. Seat plate ①

  4. Cushion spring ②

NOTE:

  • Install the seat plate with its chamfered portion @ facing the clutch boss ③.
  • Install the seat plate so that it is not caught on the step ⑥.
  • Install the cushion spring with the paint © facing out.

  • Install:

  • Friction plate 1 ①

  • Clutch plate 1 ②
  • Friction plate 2 ③
  • Clutch plate 2 ④

NOTE:

  • Install the clutch plates and friction plates alternately on the clutch boss, starting with a friction plate and ending with a friction plate.
  • Use the friction plates 1 for the first and final while paying attention to the difference in surface pattern.
  • Apply the engine oil on the friction plates and clutch plates.
  • Unlike the clutch plate 2, the clutch plate 1 has no surface gloss. Use the clutch plate 1 for the first while paying attention to the difference in surface gloss.

  • Install:

  • Bearing ①

  • Washer ②
  • Circlip ③ New

To push rod 1 ④.

NOTE:

Apply the engine oil on the bearing and washer.

  1. Courber la languette de la rondelle-frein ①.

  2. Die Lasche der Sicherungsscheibe ① umbiegen.

  3. Piegare la linguetta della rondella di bloccaggio ①.

4. Monter:

text_image Technical diagram of a mechanical assembly with numbered components and a labeled component 'E'

YAMAHA WR250FP - Monter: - 1

natural_image Mechanical assembly diagram showing a gear mechanism with no visible text or symbols

YAMAHA WR250FP - Monter: - 2

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

YAMAHA WR250FP - Monter: - 3

text_image New ② ① ①

YAMAHA WR250FP - Monter: - 4

text_image Technical diagram of a mechanical assembly with labeled components and directional arrows indicating motion or flow.

7. Install:

  • Push rod 2 ①
  • Ball ②
  • Push rod 1 ③

NOTE: \_\_\_\_

Apply the engine oil on the push rod 1, 2 and ball.

8. Install:

- Pressure plate ①

9. Install:

  • Clutch spring ①
  • Bolt (clutch spring) ②

8 Nm (0.8 m · kg, 5.8 ft · lb)

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

10. Install:

- Dowel pin ①

- Gasket (clutch cover) ②

New

11. Install:

  • Clutch cover ①
  • Bolt (clutch cover)

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE: \_\_\_\_

Tighten the bolts in stage, using a crisscross pattern.

7. Monter:

Extent of removal:
① Oil filter element removal
③ Right crankcase cover removal
② Water pump removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalOIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANK-CASE COVER REMOVALDrain the engine oil.Drain the coolant.Radiator hose 3Exhaust pipeBrake pedalRight engine guardRefer to “ENGINE OIL REPLACEMENT” section in the CHAPTER 3.Refer to “COOLANT REPLACEMENT” section in the CHAPTER 3.Disconnect at water pump side.Refer to “EXHAUST PIPE AND SILENCER” section.Refer to “ENGINE REMOVAL” section.
1312Oil filter element coverOil filter element11

ELEMENT DE FILTRE A HUILE, POMPE A EAU ET DEMI-CARTER DROIT

text_image Technical diagram of a mechanical assembly with labeled parts 1 and 2

YAMAHA WR250FP - ELEMENT DE FILTRE A HUILE, POMPE A EAU ET DEMI-CARTER DROIT - 1

text_image Technical diagram of a mechanical gear assembly with labeled parts (a) and (3)

YAMAHA WR250FP - ELEMENT DE FILTRE A HUILE, POMPE A EAU ET DEMI-CARTER DROIT - 2

natural_image Technical line drawing of mechanical components with no visible text or symbols

YAMAHA WR250FP - ELEMENT DE FILTRE A HUILE, POMPE A EAU ET DEMI-CARTER DROIT - 3

text_image Technical diagram of a mechanical assembly with labeled parts and circular annotations

YAMAHA WR250FP - ELEMENT DE FILTRE A HUILE, POMPE A EAU ET DEMI-CARTER DROIT - 4

text_image

REMOVAL POINTS Impeller shaft

1. Remove:

  • Impeller ①
  • Washer ②
  • Impeller shaft ③

NOTE:

Hold the impeller shaft on its width across the flats ⓐ with spanners, etc. and remove the impeller.

EC4G3210

Oil seal

NOTE:

It is not necessary to disassemble the water pump, unless there is an abnormality such as excessive change in coolant level, discoloration of coolant, or milky transmission oil.

  1. Remove:
  2. Bearing ①
  3. Remove:
  4. Oil seal ①

INSPECTION

Oil delivery pipe

  1. Inspect:

- Oil delivery pipe ① Bend/damage → Replace. Clogged → Blow.

POINTS DE DEPOSE

Arbre de rotor

natural_image Technical line drawing of a mechanical gear assembly with threaded shaft and central hub (no text or symbols)

YAMAHA WR250FP - Arbre de rotor - 1

natural_image Mechanical gear assembly diagram showing shaft, gear teeth, and central shaft (no text or labels)

YAMAHA WR250FP - Arbre de rotor - 2

text_image I1610101

YAMAHA WR250FP - Arbre de rotor - 3

text_image Technical diagram of a mechanical assembly with labeled parts, including circular features and numbered annotations.

YAMAHA WR250FP - Arbre de rotor - 4

text_image New ① B ② New ① B

EC444200

Impeller shaft

1. Inspect:

- Impeller shaft ① Bend/wear/damage → Replace. Fur deposits → Clean.

EC444300

Impeller shaft gear

1. Inspect:

- Gear teeth ⓐ Wear/damage → Replace.

EC4H4600

Bearing

1. Inspect:

- Bearing Rotate inner race with a finger. Rough spot/seizure → Replace.

EC444400

Oil seal

1. Inspect:

- Oil seal ① Wear/damage → Replace.

ASSEMBLY AND INSTALLATION

Oil seal

1. Install:

- Oil seal ①

New

NOTE:

  • Apply the lithium soap base grease on the oil seal lip.
  • Install the oil seal with its manufacture's marks or numbers facing the right crankcase cover ②.

Arbre de rotor

  1. Contrôler:
natural_image Technical line drawing of mechanical components with no visible text or symbols

YAMAHA WR250FP - Arbre de rotor - 1

text_image Technical diagram of a mechanical gear assembly with labeled parts and components

YAMAHA WR250FP - Arbre de rotor - 2

text_image Technical diagram of a mechanical assembly with numbered components labeled ②, ③, and ②

YAMAHA WR250FP - Arbre de rotor - 3

text_image ① ④ New ③ New ② ② New B C ①

2. Install:

- Bearing ①

NOTE:

Install the bearing by pressing its outer race parallel.

Impeller shaft

1. Install:

  • Impeller shaft ①
  • Washer ②
  • Impeller ③

14 Nm (1.4 m · kg, 10 ft · lb)

NOTE:

  • Take care so that the oil seal lip is not damaged or the spring does not slip off its position.
  • When installing the impeller shaft, apply the lithium soap base grease on the oil seal lip and impeller shaft. And install the shaft while turning it.
  • Hold the impeller shaft on its width across the flats ⓐ with spanners, etc. and install the impeller.

Right crankcase cover

1. Install:

  • Dowel pin ①
  • O-ring ②
  • Collar ③
  • Gasket ④

YAMAHA WR250FP - Install: - 1

YAMAHA WR250FP - Install: - 2

NOTE:

Apply the lithium soap base grease on the O-ring.

  1. Monter:

- Roulement ①

N.B.:

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components, likely for engineering or manufacturing documentation.

YAMAHA WR250FP - NOTE: - 2

text_image Technical diagram of a mechanical assembly with numbered components and directional arrows indicating parts of motion or flow.

YAMAHA WR250FP - NOTE: - 3

text_image Technical diagram showing a hand holding a screw with labeled parts, including numbered annotations ① and ②.

YAMAHA WR250FP - NOTE: - 4

text_image New ① ② ③ ④ ⑥

2. Install:

• Right crankcase cover ①
- Bolt (right crankcase cover) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

  • Apply the engine oil on the impeller shaft end.
  • Mesh the impeller shaft gear ③ with primary drive gear ④.
  • Tighten the bolts in stage, using a crisscross pattern.

Kickstarter crank

1. Install:

  • Kickstarter crank ①
  • Washer ②
  • Bolt (kickstarter crank) ③

YAMAHA WR250FP - Install: - 1

Install the kickstarter crank so that the kick-starter crank is as vertical as possible with the distance ⓐ between the kickstarter crank and the frame being 8 mm (0.31 in) or more.

2. Install:

  • Oil hose ①
  • Bolt (oil hose) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

3. Install:

  • Copper washer ①
  • Oil delivery pipe ②
  • Union bolt (M8) ③

18 Nm (1.8 m · kg, 13 ft · lb)

  • Union bolt (M10) ④
    20 Nm (2.0 m · kg, 14 ft · lb)

2. Monter:

text_image Technical diagram of a mechanical assembly with numbered components, likely for engineering or manufacturing documentation.

YAMAHA WR250FP - Monter: - 1

text_image ② New ② New ③ B New ②

Water pump housing

1. Install:

  • Dowel pin ①
  • O-ring ② New

NOTE: ____

Apply the lithium soap base grease on the O-ring.

2. Install:

• Water pump housing ①
- Bolt (water pump housing) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

Oil filter element

1. Install:

  • Oil filter element ①
  • O-ring ② New
  • Oil filter element cover ③
  • Bolt (oil filter element cover)

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE: ____ Apply the lithium soap base grease on the O-ring.

Extent of removal:
① Balancer shaft drive gear
② Balancer shaft

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalBALANCER REMOVALPrimary driven gearRight crankcase coverStatorRefer to “CLUTCH” section.Refer to “OIL FILTER ELEMENT,WATER PUMP AND RIGHT CRANK-CASE COVER” section.Refer to “CDI MAGNETO” section.
[WAVE] YAMAHA WR250FP - Install: - 1[X8KX]1Nut (primary drive gear)1Refer to “REMOVAL POINTS”.
2Nut (balancer shaft driven gear)1
3Lock washer1
4Primary drive gear1
5Balancer shaft drive gear1
6Lock washer1
7Balancer shaft driven gear1
8Balancer shaft1Refer to “REMOVAL POINTS”.

BALANCIER

YAMAHA WR250FP - BALANCIER - 1

text_image Technical diagram of a mechanical gear assembly with numbered components and labeled parts

YAMAHA WR250FP - BALANCIER - 2

text_image Technical diagram of a mechanical gear assembly with numbered components labeled ①, ②, and ③.

YAMAHA WR250FP - BALANCIER - 3

text_image Technical diagram of a mechanical gear assembly with labeled parts 1 and 2

YAMAHA WR250FP - BALANCIER - 4

text_image Technical diagram showing three types of gear components with numbered labels (①, ②, ③) indicating different gear types.

YAMAHA WR250FP - BALANCIER - 5

natural_image Line drawing of a mechanical tool with threaded end and handle (no text or symbols)

REMOVAL POINTS

Balancer shaft drive gear and balancer shaft driven gear

  1. Straighten the lock washer tab.
  2. Loosen:

  3. Nut (primary drive gear) ①

  4. Nut (balancer shaft driven gear) ②

NOTE:

Place an aluminum plate ⓐ between the teeth of the balancer shaft drive gear ③ and driven gear ④.

Balancer shaft

  1. Remove:

- Balancer shaft ①

NOTE:

When removing the balancer shaft, align the center ⓐ of the balancer shaft weight along the line connecting the centers of the crank-shaft and balancer shaft.

INSPECTION

Primary drive gear, balancer shaft drive gear and balancer shaft driven gear

  1. Inspect:

  2. Primary drive gear ①

  3. Balancer shaft drive gear ②
  4. Balancer shaft driven gear ③
    Wear/damage → Replace.

Balancer shaft

  1. Inspect:

  2. Balancer shaft
    Cracks/damage → Replace.

POINTS DE DEPOSE

text_image Technical diagram of a mechanical gear assembly with labeled parts 1 and 2

YAMAHA WR250FP - POINTS DE DEPOSE - 1

text_image Technical diagram of gear meshing with labeled components a and b, showing gear arrangement and assembly details.

YAMAHA WR250FP - POINTS DE DEPOSE - 2

text_image Technical diagram of a mechanical gear assembly with labeled components (a, b, c, d) and numbered parts.

YAMAHA WR250FP - POINTS DE DEPOSE - 3

text_image Technical diagram of a mechanical gear assembly with numbered components labeled ① through ⑥

YAMAHA WR250FP - POINTS DE DEPOSE - 4

text_image Technical diagram of a mechanical gear assembly with numbered components and directional arrow indicating motion or movement.

ASSEMBLY AND INSTALLATION

Balancer shaft, balancer shaft drive gear and balancer shaft driven gear

1. Install:

- Balancer shaft ①

NOTE:

  • Apply the engine oil on the bearing.
  • When installing the balancer shaft, align the center ⓐ of the balancer shaft weight along the line connecting the centers of the crank-shaft and balancer shaft.

2. Install:

- Balancer shaft driven gear ①

NOTE:

Install the balancer shaft driven gear onto the balancer shaft while aligning the punch mark Ⓐ on the balancer shaft driven gear with the lower spline ⓑ on the balancer shaft end.

3. Install:

- Balancer shaft drive gear ①

NOTE:

  • Align the punched mark ⓐ on the balancer shaft drive gear with the punched mark ⓑ on the balancer shaft driven gear ②.
  • Align the punched mark © on the balancer shaft drive gear with the lower spline ⓐ on the crankshaft end.

4. Install:

  • Lock washer ①
  • Nut (balancer shaft driven gear) ②

YAMAHA WR250FP - Install: - 1

- Primary drive gear ③

- Nut (primary drive gear) ④

YAMAHA WR250FP - Install: - 2

NOTE:

  • Install the primary drive gear with its stepped side ⓐ facing the engine.
  • Place an aluminum plate ⑥ between the teeth of the balancer shaft drive gear ⑤ and driven gear ⑥.

5. Bend the lock washer tab.

ASSEMBLAGE ET INSTALLATION

Extent of removal:
① Oil pump removal
② Oil pump disassembly

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalOIL PUMP REMOVAL AND DISASSEMBLYPrimary driven gearRight crankcase coverRefer to “CLUTCH” section.Refer to “OIL FILTER ELEMENT,WATER PUMP AND RIGHT CRANK-CASE COVER” section.
[80C1]1Circlip1
2Washer1
3Oil pump drive gear1
4Oil pump assembly1
5Outer rotor 21
6Circlip1
7Inner rotor 21
8Dowel pin1
9Oil pump cover1
10Outer rotor 11
11Inner rotor 11

POMPE A HUILE

YAMAHA WR250FP - POMPE A HUILE - 1

text_image Technical diagram of four mechanical gear components with numbered labels for identification.

YAMAHA WR250FP - POMPE A HUILE - 2

text_image Technical diagram of a mechanical assembly with labeled components and dimensional annotations

INSPECTION

Oil pump

1. Inspect:

  • Oil pump drive gear ①
  • Oil pump drive shaft ②
  • Rotor housing ③
  • Oil pump cover ④

Cracks/wear/damage → Replace.

2. Measure:

  • Tip clearance ① (between the inner rotor ① and outer rotor ②)
  • Side clearance ⑥ (between the outer rotor ② and rotor housing ③)
  • Housing and rotor clearance © (between the rotor housing ③ and rotors ① ②)

Out of specification → Replace the oil pump assembly.

YAMAHA WR250FP - Measure: - 1

Tip clearance ⓐ:

0.12 mm or less

(0.0047 in or less)

: 0.20 mm (0.008 in)

Side clearance ⓑ:

0.09 \~ 0.17 mm (0.0035 \~ 0.0067 in)

: 0.24 mm (0.009 in)

Housing and rotor clearance ©:

0.03 \~ 0.10 mm (0.0012 \~ 0.0039 in)

: 0.17 mm (0.0067 in)

YAMAHA WR250FP - Measure: - 2

natural_image Line drawing of a hand turning a gear mechanism with an arrow indicating rotational motion (no text or symbols)

3. Check:

- Unsmooth → Repeat steps #1 and #2 or replace the defective parts.

CONTROLE

Pompe à huile

1. Contrôler:

ASSEMBLY AND INSTALLATION

Oil pump

1. Install:

  • Oil pump drive shaft ①
  • Washer ②
  • Dowel pin ③
  • Inner rotor 1 ④

NOTE:

  • Apply the engine oil on the oil pump drive shaft and inner rotor 1.
  • Fit the dowel pin into the groove in the inner rotor 1.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical component with labeled parts and an arrow indicating direction

2. Install:

- Outer rotor 1 ①

NOTE:

Apply the engine oil on the outer rotor 1.

YAMAHA WR250FP - NOTE: - 1

text_image New ① ② ③ ④ ⑤ ⑥ E

3. Install:

  • Oil pump cover ①
  • Screw (oil pump cover) ②
  • Dowel pin ③
  • Inner rotor 2 ④
  • Circlip ⑤
    New

YAMAHA WR250FP - Install: - 1

3 Nm (0.3 m · kg, 2.2 ft · lb)

NOTE:

  • Apply the engine oil on the inner rotor 2.
  • Fit the dowel pin into the groove in the inner rotor 2.

ASSEMBLAGE ET INSTALLATION

Pompe à huile

text_image Technical diagram of a mechanical assembly with numbered components and a labeled component E

4. Install:

  • Outer rotor 2 ①
  • Dowel pin ②
  • Oil pump assembly ③
  • Bolt (oil pump assembly) [L = 25 mm (0.94 in)] ④

10 Nm (1.0 m · kg, 7.2 ft · lb)

- Bolt (oil pump assembly) [L = 30 mm (1.18 in)] ⑤

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Apply the engine oil on the outer rotor 2.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing gear assembly with labeled components and a 'New' label, likely from an engineering or manufacturing context.

5. Install:

  • Oil pump drive gear ①
  • Washer ②
  • Circlip ③ New

NOTE:

Apply the engine oil on the oil pump drive gear inner circumference.

4. Monteur:

KICK SHAFT AND SHIFT SHAFT
YAMAHA WR250FP - Monteur: - 1

YAMAHA WR250FP - Monteur: - 2

text_image New 10 Nm (1.0 m·kg, 7.2 ft·lb) 20 21 22 30 Nm (3.0 m·kg, 22 ft·lb) 10 Nm (1.0 m·kg, 7.2 ft·lb)

Extent of removal:
① Kick shaft removal
② Kick shaft disassembly
③ Shift shaft removal
④ Segment removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalKICK SHAFT AND SHIFT SHAFT REMOVALOil pumpRefer to “OIL PUMP” section.
1↓2↓1↑34↓1Kick idle gear1Refer to “REMOVAL POINTS”.
2Kick shaft assembly1
3Spring guide1
4Torsion spring1
5Ratchet wheel1
6Kick gear1
7Kick shaft1
8Washer1
9Shift pedal1
10Shift shaft1
11Collar1

ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO

text_image Technical diagram of a mechanical gear assembly with labeled components and motion indicators

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 1

text_image Technical diagram of engine cylinder components with numbered labels indicating parts of the engine assembly.

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 2

text_image Technical diagram showing mechanical components with numbered parts and an upward arrow indicating motion or assembly.

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 3

text_image Technical diagram of a mechanical gear assembly with numbered components and directional arrow indicating rotation or movement.

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 4

text_image Technical diagram of three gear components with labeled parts a, b, and numbered annotations

REMOVAL POINTS

Kick shaft assembly

1. Remove:

- Kick shaft assembly ①

NOTE:

Unhook the torsion spring ② from the hole ④ in the crankcase.

EC4C3101

Shift guide and shift lever assembly

1. Remove:

  • Bolt (shift guide)
  • Shift guide ①
  • Shift lever assembly ②

NOTE:

The shift lever assembly is disassembled at the same time as the shift guide.

EC4N3100

Segment

1. Remove:

  • Bolt (segment) ①
  • Segment ②

NOTE:

Turn the segment counterclockwise until it stops and loosen the bolt.

INSPECTION

Kick shaft and ratchet wheel

1. Check:

  • Ratchet wheel ① smooth movement Unsmooth movement → Replace.
  • Kick shaft ② Wear/damage → Replace.
  • Spring ③ Broken → Replace.

EC4C4300

Kick gear, kick idle gear and ratchet wheel

1. Inspect:

  • Kick gear ①
  • Kick idle gear ②
  • Ratchet wheel ③
  • Gear teeth ⓐ

- Ratchet teeth ⑥ Wear/damage → Replace.

ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO

POINTS DE DEPOSE

Arbre de kick complet

  1. Déposer:
text_image Technical diagram of a mechanical tool with labeled parts ① and ②

YAMAHA WR250FP - Arbre de kick complet - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - Arbre de kick complet - 2

natural_image Technical line drawing of two mechanical clamping components (no text or symbols)

YAMAHA WR250FP - Arbre de kick complet - 3

text_image Technical diagram of mechanical assembly with labeled parts a, b, and c

EC4B4400

Shift shaft

1. Inspect:

  • Shift shaft ①
    Bend/damage → Replace.
  • Spring ②
    Broken → Replace.

EC4C4100

Shift guide and shift lever assembly

1. Inspect:

  • Shift guide ①
  • Shift lever ②
  • Pawl ③
  • Pawl pin ④
  • Spring ⑤

Wear/damage → Replace.

EC4B4500

Stopper lever

1. Inspect:

  • Stopper lever ①
    Wear/damage → Replace.
  • Torsion spring ②
    Broken → Replace.

ASSEMBLY AND INSTALLATION

Segment

1. Install:

  • Segment ①
  • Bolt (segment)

YAMAHA WR250FP - Install: - 1

30 Nm (3.0 m · kg, 22 ft · lb)

NOTE:

Align the notch ① on the segment with the pin ② on the shift cam.

ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO

Arbre de sélecteur

text_image Technical diagram of a mechanical gear assembly with numbered components

EC4B5111

Stopper lever

1. Install:

  • Torsion spring ①
  • Stopper lever ②
  • Bolt (stopper lever) ③

YAMAHA WR250FP - Install: - 1

YAMAHA WR250FP - Install: - 2

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Align the stopper lever roller with the slot on segment.

YAMAHA WR250FP - NOTE: - 1

text_image Diagram of a medical or laboratory procedure with labeled components including a magnified view and a device labeled E.

Shift guide and shift lever assembly

1. Install:

  • Spring ①
  • Pawl pin ②
  • Pawl ③

To shift lever ④.

NOTE:

Apply the engine oil on the spring, pawl pin and pawl.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical component with labeled parts ① and ②

2. Install:

- Shift lever assembly ①

To shift guide ②.

YAMAHA WR250FP - Install: - 1

text_image Technical diagram of engine cylinder assembly with labeled parts and tool indicator

3. Install:

  • Shift lever assembly ①
  • Shift guide ②

NOTE:

  • The shift lever assembly is installed at the same time as the shift guide.
  • Apply the engine oil on the bolt (segment) shaft.

ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO

Levier de butée

text_image Technical diagram of a mechanical assembly with numbered components and directional arrows indicating motion or flow.

YAMAHA WR250FP - Levier de butée - 1

text_image Technical diagram of an engine cylinder assembly with numbered components and labeled parts E

YAMAHA WR250FP - Levier de butée - 2

text_image Technical diagram of a mechanical assembly with labeled components and directional arrows indicating motion or flow.

YAMAHA WR250FP - Levier de butée - 3

text_image New ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ New

4. Install:

- Bolt (shift guide) ①

YAMAHA WR250FP - Install: - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

Shift shaft

1. Install:

  • Roller ①
  • Collar ②
  • Torsion spring ③
  • Shift shaft ④

NOTE:

Apply the engine oil on the roller and shift shaft.

2. Install:

  • Shift pedal ①
  • Bolt (shift pedal) ②

NOTE:

When installing the shift pedal onto the shift shaft, be sure that the center of the shift pedal is about 2 mm ⓐ above the top of the footrest.

Kick shaft assembly

1. Install:

  • Kick gear ①
  • Washer ②
  • Circlip ③ New
  • Ratchet wheel ④
  • Spring ⑤
  • Washer ⑥
  • Circlip ⑦ New

To kick shaft ⑧.

NOTE:

  • Apply the molybdenum disulfide oil on the inner circumferences of the kick gear and ratchet wheel.
  • Align the punch mark ⓐ on the ratchet wheel with the punch mark ⓑ on the kick shaft.

ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO

  1. Monter:
text_image Technical diagram showing gear and cable assembly with labeled parts 1, 2, and b

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 1

text_image Technical diagram of a mechanical gear assembly with labeled parts ① and ②

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 2

text_image Technical diagram of a mechanical assembly with labeled parts and a valve indicator

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 3

natural_image Technical line drawing of a mechanical gear assembly with no visible text or symbols

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 4

text_image Technical diagram of mechanical gear assembly with labeled parts and a magnified view of a gear mechanism

2. Install:

- Torsion spring ① To kick shaft ②.

NOTE:

Make sure the stopper ⓐ of the torsion spring fits into the hole ⓑ on the kick shaft.

3. Install:

- Spring guide ①

NOTE:

Slide the spring guide into the kick shaft, make sure the groove ⓐ in the spring guide fits on the stopper of the torsion spring.

4. Install:

  • Kick shaft assembly ①
  • Washer ②

NOTE:

  • Apply the molybdenum disulfide grease on the contacting surfaces of the kick shaft stopper ① and stopper plate ③.
  • Apply the engine oil on the kick shaft.
  • Slide the kick shaft assembly into the crank-case and make sure the kick shaft stopper fits into the stopper plate.

5. Hook:

- Torsion spring ①

NOTE:

Turn the torsion spring clockwise and hook into the proper hole ⓐ in the crankcase.

Kick idle gear

1. Install:

  • Kick idle gear ①
  • Washer ②
  • Circlip ③ New

NOTE:

  • Apply the engine oil on the kick idle gear inner circumference.
  • Install the kick idle gear with its depressed side @ toward you.

ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO

ENG

YAMAHA WR250FP - ARBRE DE KICK ET ARBRE DE SELECTEUR KICKSTARTER UND KICKSTARTERWELLE ALBERO PEDALE E ALBERO DEL CAMBIO - 1

2. Monter:

Extent of removal:
① CDI magneto removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCDI MAGNETO REMOVALSeat and fuel tankBolt (left radiator)Disconnect the CDI magneto lead.Shift pedalRefer to “SEAT, FUEL TANK AND SIDE COVERS” section.Refer to “RADIATOR” section.Refer to “KICK SHAFT AND SHIFT SHAFT” section.
11Left engine guard1Use special tool.Refer to “REMOVAL POINTS”.
2Left crankcase cover1
3Nut (rotor)1
4Rotor1
5Stator1
6Woodruff key1

VOLANT MAGNETIQUE CDI

YAMAHA WR250FP - VOLANT MAGNETIQUE CDI - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - VOLANT MAGNETIQUE CDI - 2

text_image 1.0mm 32mm 6mm ① ③ ②

EC4L3000

REMOVAL POINTS

Rotor

  1. Remove:

  2. Nut (rotor) ①

  3. Washer ②

Use the rotor holding tool ③.

YAMAHA WR250FP - Rotor - 1

Rotor holding tool: YU-1235/90890-01235

  1. Remove:

- Rotor ①

Use the flywheel puller ②.

YAMAHA WR250FP - Rotor - 2

Flywheel puller: YU-33270-B/90890-01362

NOTE:

Install three bolts ③ of the proper size, as shown in illustration.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with labeled parts, showing internal components and a close-up view.

YAMAHA WR250FP - NOTE: - 2

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

EC4L4000

INSPECTION

EC4L4101

CDI magneto

  1. Inspect:

  2. Rotor inner surface ⓐ

  3. Stator outer surface ⓑ

Damage → Inspect the crankshaft runout and crankshaft bearing.

If necessary, replace CDI magneto and/or stator.

EC4L4200

Woodruff key

  1. Inspect:

- Woodruff key ①

Damage → Replace.

POINTS DE DEPOSE

Rotor

1. Déposer:

  • Ecrou (rotor) ①
  • Rondelle ②
text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

EC4L5000

ASSEMBLY AND INSTALLATION

CDI magneto

  1. Install:

  2. Stator ①

  3. Screw (stator) ②

YAMAHA WR250FP - CDI magneto - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

  • Apply the sealant on the grommet of the CDI magneto lead.
  • Tighten the screws using the T30 bit.

YAMAHA WR250FP - NOTE: - 1

Quick gasket®:

ACC-QUICK-GS-KT

YAMAHA Bond No. 1215:

90890-85505

YAMAHA WR250FP - NOTE: - 2

text_image Technical diagram of a mechanical assembly with labeled parts and an inset showing a component detail view.
  1. Install:

  2. Woodruff key ①

  3. Rotor ②

NOTE:

  • Clean the tapered portions of the crankshaft and rotor.
  • When installing the woodruff key, make sure that its flat surface ① is in parallel with the crankshaft center line ⑥.
  • When installing the rotor, align the keyway © of the rotor with the woodruff key.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components, likely illustrating a gear or cam mechanism.
  1. Install:

  2. Washer ①

  3. Nut (rotor) ②

YAMAHA WR250FP - NOTE: - 2

48 Nm (4.8 m · kg, 35 ft · lb)

Use the rotor holding tool ③.

YAMAHA WR250FP - NOTE: - 3

Rotor holding tool:

YU-1235/90890-01235

ASSEMBLAGE ET MONTAGE

  1. Monter:

  2. Stator ①

  3. Vis (stator) ②

10 Nm (1,0 m · kg, 7,2 ft · lb)

N.B.:

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - N.B.: - 1

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

4. Connect:

- CDI magneto lead Refer to “CABLE ROUTING DIAGRAM” section in the CHAPTER 2.

5. Install:

  • Dowel pin
    • Gasket (left crankcase cover)
  • Left crankcase cover ①
  • Hose guide (cylinder head breather hose) ②
  • Bolt (left crankcase cover) ③

YAMAHA WR250FP - Install: - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

6. Install:

  • Left engine guard ①
  • Hose holder (cylinder head breather hose) ②
  • Bolt (left engine guard) ③
    23 Nm (2.3 m · kg, 17 ft · lb)
  • Cylinder head breather hose ④

4. Connector:

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalENGINE REMOVALHold the machine by placing the suitable stand under the frame.Seat and fuel tankCarburetorExhaust pipe and silencerClutch cableDecompression cable and guideRadiatorShift pedalCylinder head breather hose and oil tank breather hoseDrain the engine oil⚠ WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “SEAT, FUEL TANK AND SIDE COVERS” section.Refer to “CARBURETOR” section.Refer to “EXHAUST PIPE AND SILENCER” section.Disconnect at engine side.Disconnect at engine side.Refer to “RADIATOR” section.Refer to “KICK SHAFT AND SHIFT SHAFT” section.Refer to “CAMSHAFTS” section.Refer to “ENGINE OIL REPLACEMENT” section in the CHAPTER 3.

DEPOSE DU MOTEUR

Extent of removal:
① Engine removal

Extent of removalOrderPart nameQ'tyRemarks
Spark plug capDisconnect the CDI magneto lead.Right engine guard
11Neutral switch1Refer to “REMOVAL POINTS”.
2Bolt (oil hose)2
3Drive chain sprocket cover1
4Nut (drive sprocket)1
5Lock washer1
6Drive sprocket1
7Clip1
8Bolt (brake pedal)1
9Brake pedal1
10Upper engine bracket2
11Lower engine bracket2
12Engine mounting bolt3
13Pivot shaft1Refer to “REMOVAL POINTS”.
14Engine1
text_image Technical diagram of a mechanical gear assembly with labeled components 1 and 2

YAMAHA WR250FP - Connector: - 1

text_image Technical diagram of a mechanical gear assembly with labeled parts ① and ②

YAMAHA WR250FP - Connector: - 2

text_image Technical diagram showing mechanical assembly with labeled component ①

YAMAHA WR250FP - Connector: - 3

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

EC4M3000

REMOVAL POINTS

EC4F3100

Drive sprocket

  1. Remove:

  2. Nut (drive sprocket) ①

  3. Lock washer ②

NOTE:

  • Straighten the lock washer tab.
  • Loosen the nut while applying the rear brake.

  • Remove:

  • Drive sprocket ①

  • Drive chain ②

NOTE:

Remove the drive sprocket together with the drive chain.

EC4M3301

Engine removal

  1. Remove:

- Pivot shaft ①

NOTE:

If the pivot shaft is pulled all the way out, the swingarm will come loose. If possible, insert a shaft of similar diameter into the other side of the swingarm to support it.

  1. Remove:

- Engine ①

From right side.

NOTE:

Make sure that the couplers, hoses and cables are disconnected.

POINTS DE DEPOSE

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - POINTS DE DEPOSE - 1

text_image New ① ② ③ ④ B ⑤ ⑥ a

EC4M5000

ASSEMBLY AND INSTALLATION

Engine installation

  1. Install:

  2. Engine ① Install the engine from right side.

  3. Pivot shaft ②

85 Nm (8.5 m · kg, 61 ft · lb)

- Engine mounting bolt (lower) ③

  • Lower engine bracket ④
  • Bolt (engine bracket) ⑤

• Engine mounting bolt (front) ⑥

• Upper engine bracket ⑦
- Engine mounting bolt (upper) ⑧

55 Nm (5.5 m · kg, 40 ft · lb)

- Bolt (engine guard) ⑨

23 Nm (2.3 m · kg, 17 ft · lb)

EC4M5211

Brake pedal

  1. Install:

  2. Spring ①

  3. Brake pedal ②
  4. O-ring ③ New

- Bolt (brake pedal) ④

26 Nm (2.6 m · kg, 19 ft · lb)

- Clip ⑤

NOTE:

  • Apply the lithium soap base grease on the bolt, O-rings and brake pedal bracket.
  • Install the clip with its stopper portion ⓐ facing inward.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical gear assembly with labeled components ① and ②

Drive sprocket

  1. Install:

  2. Drive sprocket ①

  3. Drive chain ②

NOTE:

Install the drive sprocket together with the drive chain.

text_image Technical diagram of a mechanical gear assembly with labeled components and a 'New' label

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components and dashed lines indicating alignment or connection points.

YAMAHA WR250FP - NOTE: - 2

text_image New ① ② ③ ④

2. Install:

  • Lock washer ① New
  • Nut (drive sprocket) ②

Tighten the nut while applying the rear brake.

3. Bend the lock washer tab to lock the nut.

4. Install:

  • Drive chain sprocket guide ①
  • Drive chain sprocket cover ②
  • Screw (drive chain sprocket cover) ③

8 Nm (0.8 m · kg, 5.8 ft · lb)

Oil hose and neutral switch

1. Install:

  • O-ring ① New
  • Dowel pin ②
  • Oil hose ③
  • Bolt (oil hose) ④

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Apply the lithium soap base grease on the O-ring.

YAMAHA WR250FP - NOTE: - 1

text_image New ① ② ③ ④ ⑤ B

2. Install:

  • Spring ①
  • Pin ②
  • O-ring ③ New
  • Neutral switch ④
  • Screw (neutral switch) ⑤

YAMAHA WR250FP - Install: - 1

4 Nm (0.4 m · kg, 2.9 ft · lb)

NOTE:

Apply the lithium soap base grease on the O-ring.

  1. Monter:

- Joint torque ③ New

CRANKCASE AND CRANKSHAFT

YAMAHA WR250FP - CRANKCASE AND CRANKSHAFT - 1

text_image 10 Nm (1.0 m·kg, 7.2 ft·lb) New 10 Nm (1.0 m·kg, 7.2 ft·lb) 12 Nm (1.2 m·kg, 8.7 ft·lb)

Extent of removal:
① Crankcase separation
② Crankshaft removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCRANKCASE AND CRANK-SHAFT REMOVALEnginePistonKick shaft assemblySegmentStatorBalancer shaftRefer to “ENGINE REMOVAL” section.Refer to “CYLINDER AND PISTON” section.Refer to “KICK SHAFT AND SHIFT SHAFT” section.Refer to “CDI MAGNETO” section.Refer to “BALANCER” section.
123123Timing chain guide (intake side)Timing chainOil delivery pipe 2111

Extent of removal:
① Crankcase bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCRANKCASE BEARING REMOVALTransmissionShift cam and shift forkRefer to “TRANSMISSION, SHIFT CAM AND SHIFT FORK” section.
1↓1Oil seal2Refer to “REMOVAL POINTS”.
2Bearing10

ROULEMENTS DE CARTER

text_image Technical diagram of a mechanical assembly with numbered components labeled 1, 2, and 3.

YAMAHA WR250FP - ROULEMENTS DE CARTER - 1

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - ROULEMENTS DE CARTER - 2

natural_image Technical line drawing of a mechanical assembly with gears and shafts (no text or symbols)

REMOVAL POINTS Crankcase

1. Separate:

  • Right crankcase
  • Left crankcase

Separation steps:

- Remove the crankcase bolts ①, hose guide ② and clutch cable holder ③.

NOTE:

Loosen each bolt 1/4 of a turn at a time and after all the bolts are loosened, remove them.

- Remove the right crankcase ④.

NOTE:

  • Place the crankcase with its left side downward and split it by inserting a screw-driver tip into the splitting slit ⓐ in the crankcase.
  • Lift the right crankcase horizontally while lightly patting the case splitting slit and engine mounting boss using a soft hammer, and leave the crankshaft and transmission with the left crankcase.

CAUTION:

Use soft hammer to tap on the case half. Tap only on reinforced portions of case. Do not tap on gasket mating surface. Work slowly and carefully. Make sure the case halves separate evenly. If one end “hangs up”, take pressure off the push screw, realign, and start over. If the cases do not separate, check for a remaining case screw or fitting. Do not force.

- Remove the dowel pins and O-ring.

POINTS DE DEPOSE

Carter

  1. Séparer:
text_image Technical diagram of a mechanical assembly with numbered components labeled ① and ②

YAMAHA WR250FP - Carter - 1

text_image Technical diagram showing mechanical assembly with labeled components and a schematic view of a loading mechanism.

YAMAHA WR250FP - Carter - 2

natural_image Diagram of a chain with two circular loops, no text or symbols present

YAMAHA WR250FP - Carter - 3

text_image Technical diagram of a mechanical component with labeled parts (a) and (b)

YAMAHA WR250FP - Carter - 4

text_image I1610101

Crankshaft

1. Remove:

- Crankshaft ①

Use the crankcase separating tool ②.

YAMAHA WR250FP - Remove: - 1

Crankcase separating tool: YU-1135-A/90890-01135

CAUTION:

Do not use a hammer to drive out the crankshaft.

Crankcase bearing

1. Remove:

- Bearing ①

NOTE:

  • Remove the bearing from the crankcase by pressing its inner race.
  • Do not use the removed bearing.

INSPECTION

Timing chain and timing chain guide

1. Inspect:

- Timing chain Cracks/stiff → Replace the timing chain and camshaft sprocket as a set.

2. Inspect:

- Timing chain guide Wear/damage → Replace.

Crankcase

1. Inspect:

  • Contacting surface ⓐ Scratches → Replace
  • Engine mounting boss ⑥, crankcase Cracks/damage → Replace.

2. Inspect:

- Bearing Rotate inner race with a finger. Rough spot/seizure → Replace.

3. Inspect:

- Oil seal Damage → Replace.

Vilebrequin

  1. Déposer:

- Vilebrequin ①

  • Runout limit ⓐ
  • Small end free play limit ⓑ
  • Connecting rod big end side clearance ©
  • Crank width ⓓ
    Out of specification → Replace.
    Use the dial gauge and a thickness gauge.

YAMAHA WR250FP - Vilebrequin - 1

Dial gauge and stand: YU-3097/90890-01252

YAMAHA WR250FP - Vilebrequin - 2Standard
Runout limit:0.03 mm (0.0012 in)0.05 mm (0.002 in)
Small end free play:0.4 ~ 1.0 mm (0.016 ~ 0.039 in)2.0 mm (0.08 in)
Side clearance:0.15 ~ 0.45 mm (0.0059 ~ 0.0177 in)0.50 mm (0.02 in)
Crack width:55.95 ~ 56.00 mm (2.203 ~ 2.205 in)

YAMAHA WR250FP - Vilebrequin - 3

natural_image Simple line drawing of a computer monitor with a screen and antenna (no text or symbols)

YAMAHA WR250FP - Vilebrequin - 4

text_image Technical diagram of a mechanical linkage with labeled parts and connection points

Oil strainer

1. Inspect:

  • Oil strainer
    Damage → Replace.

Oil delivery pipe 2

1. Inspect:

  • Oil delivery pipe 2 ①
  • O-ring ②
    Damage → Replace.
  • Oil orifice ⓐ
    Clogged → Blow.

Vilebrequin

1. Mesurer:

text_image Technical diagram of an engine cylinder with labeled components and parts, including a bolt and inset view.

YAMAHA WR250FP - Mesurer: - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - Mesurer: - 2

text_image A ② ③ ④ ⑤

YAMAHA WR250FP - Mesurer: - 3

text_image B ② ③ ④ ⑤

EC4N5000

ASSEMBLY AND INSTALLATION

Crankcase bearing

  1. Install:

  2. Bearing
    New

  3. Bearing stopper
  4. Bolt (bearing stopper)

YAMAHA WR250FP - Crankcase bearing - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

- Screw (bearing stopper)

YAMAHA WR250FP - Crankcase bearing - 2

10 Nm (1.0 m · kg, 7.2 ft · lb)

- Screw [bearing stopper (crankshaft)] ①

YAMAHA WR250FP - Crankcase bearing - 3

10 Nm (1.0 m · kg, 7.2 ft · lb)

To left and right crankcase.

NOTE:

  • Install the bearing by pressing its outer race parallel.
  • To prevent the screw [bearing stopper (crankshaft)] from becoming loose, crush the screw head periphery ⓐ into the concave ⓑ using a punch etc. In so doing, take care not to damage the screwdriver receiving hole in the screw head.

Crankshaft

  1. Install:

- Crankshaft ①

Use the crankshaft installing tool ②, ③, ④, ⑤.

YAMAHA WR250FP - Crankshaft - 1

Crankshaft installing pot ②: YU-90050/90890-01274

Crankshaft installing bolt ③: YU-90050/90890-01275

Adapter (M10) ④: YM-1277/90890-01277 Spacer (crankshaft installer) ⑤: YU-91044/90890-04081

A For USA and CDN
B Except for USA and CDN

NOTE:

  • Hold the connecting rod at top dead center with one hand while turning the nut of the installing tool with the other. Operate the installing tool until the crankshaft bottoms against the bearing.
  • Before installing the crankshaft, clean the contacting surface of crankcase.

CAUTION:

Do not use a hammer to drive in the crankshaft.

ASSEMBLAGE ET MONTAGE

Roulement de carter

  1. Installer:

- Roulement

YAMAHA WR250FP - Roulement de carter - 1

natural_image Mechanical assembly diagram showing gear and shaft components (no text or labels)

YAMAHA WR250FP - Roulement de carter - 2

text_image Technical diagram of a mechanical assembly with numbered components, likely for engine or valve design reference.

YAMAHA WR250FP - Roulement de carter - 3

natural_image Technical line drawing of a mechanical gear assembly with no visible text or symbols

YAMAHA WR250FP - Roulement de carter - 4

text_image ① ① ② New ① B

2. Check:

  • Shifter operation
    • Transmission operation
    Unsmooth operation → Repair.

3. Install:

  • Oil strainer ①
  • Bolt (oil strainer) ②

YAMAHA WR250FP - Install: - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

4. Apply:

  • Sealant
    On the right crankcase ①.

YAMAHA WR250FP - Apply: - 1

Quick gasket®: ACC-QUICK-GS-KT YAMAHA Bond No. 1215: 90890-85505

NOTE:

Clean the contacting surface of left and right crankcase before applying the sealant.

5. Install:

  • Dowel pin ①
  • O-ring ② New
  • Right crankcase
    To left crankcase.

NOTE:

  • Fit the right crankcase onto the left crankcase. Tap lightly on the case with soft hammer.
  • When installing the crankcase, the connecting rod should be positioned at TDC (top dead center).
text_image Technical diagram of a mechanical assembly with numbered components labeled ①, ②, and ③.

YAMAHA WR250FP - NOTE: - 1

text_image New ① ② ③ B

YAMAHA WR250FP - NOTE: - 2

text_image Technical diagram of a mechanical assembly with numbered components, likely for assembly or maintenance reference.

6. Tighten:

  • Hose guide ①
  • Clutch cable holder ②
  • Bolt (crankcase) ③

YAMAHA WR250FP - Tighten: - 1

12 Nm (1.2 m · kg, 8.7 ft · lb)

NOTE:

Tighten the crankcase tightening bolts in stage, using a crisscross pattern.

7. Install:

  • Oil delivery pipe 2 ①
  • O-ring ② New
  • Bolt (oil delivery pipe 2) ③

YAMAHA WR250FP - Install: - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

Apply the lithium soap base grease on the O-rings.

8. Install:

  • Timing chain ①
  • Timing chain guide (intake side) ②
  • Bolt (timing chain guide) ③

YAMAHA WR250FP - Install: - 1

10 Nm (1.0 m · kg, 7.2 ft · lb)

9. Remove:

  • Sealant
    Forced out on the cylinder mating surface.

10. Apply:

  • Engine oil
    To the crank pin, bearing and oil delivery hole.

11. Check:

- Crankshaft and transmission operation. Unsmooth operation → Repair.

TRANSMISSION, SHIFT CAM AND SHIFT FORK

YAMAHA WR250FP - TRANSMISSION, SHIFT CAM AND SHIFT FORK - 1

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts (A–M)

Extent of removal:
① Shift fork, shift cam, main axle and drive axle removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalTRANSMISSION, SHIFT CAM AND SHIFT FORK REMOVALEngineSeparate the crankcase.Refer to “ENGINE REMOVAL” section.Refer to “CRANKCASE AND CRANK-SHAFT” section.
11Main axle1Refer to “REMOVAL POINTS”.
2Drive axle1
3Shift cam1
4Shift fork 31
5Shift fork 21
6Shift fork 11
7Collar1

BOITE A VITESSES, TAMBOUR ET FOURCHETTES DE SELECTION

text_image Technical diagram of a mechanical assembly with numbered components, likely for maintenance or repair instructions.

YAMAHA WR250FP - BOITE A VITESSES, TAMBOUR ET FOURCHETTES DE SELECTION - 1

text_image a b c

YAMAHA WR250FP - BOITE A VITESSES, TAMBOUR ET FOURCHETTES DE SELECTION - 2

natural_image Technical line drawing of a mechanical gear assembly with no visible text or symbols

YAMAHA WR250FP - BOITE A VITESSES, TAMBOUR ET FOURCHETTES DE SELECTION - 3

text_image Technical drawing of a mechanical bearing assembly with sectional views and dimension annotations

EC4H3000

REMOVAL POINTS

EC4H3230

Transmission

1. Remove:

  • Main axle ①
  • Drive axle ②
  • Shift cam
  • Shift fork 3
  • Shift fork 2
  • Shift fork 1

NOTE:

  • Remove assembly with the collar ③ installed to the crankcase.
  • Remove assembly carefully. Note the position of each part. Pay particular attention to the location and direction of shift forks.
  • Remove the main axle, drive axle, shift cam and shift fork all together by tapping lightly on the transmission drive axle with a soft hammer.

EC4H4000

INSPECTION

EC4H4200

Gears

1. Inspect:

  • Matching dog ⓐ
  • Gear teeth ⓑ
  • Shift fork groove ©
    Wear/damage → Replace.

2. Inspect:

  • O-ring ①
    Damage → Replace.

3. Check:

  • Gears movement
    Unsmooth movement → Repair or replace.

EC4H4600

Bearing

1. Inspect:

  • Bearing ①
    Rotate inner race with a finger.
    Rough spot/seizure → Replace.

POINTS DE DEPOSE

Boîte à vitesses

  1. Déposer:

  2. Arbre primaire ①

  3. Arbre secondaire ②
  4. Tambour
  5. Fourchette 3
  6. Fourchette 2
  7. Fourchette 1

N.B.:

text_image Technical diagram of a mechanical linkage or assembly with labeled component 1

YAMAHA WR250FP - Boîte à vitesses - 1

text_image Technical diagram of a mechanical component with labeled parts ① and ②

YAMAHA WR250FP - Boîte à vitesses - 2

natural_image Technical line drawing of a mechanical assembly with hands adjusting components (no text or symbols)

YAMAHA WR250FP - Boîte à vitesses - 3

text_image Technical diagram of mechanical assembly with numbered components and a labeled component M

EC4H4810

Shift fork, shift cam and segment

1. Inspect:

- Shift fork ①

Wear/damage/scratches → Replace.

2. Inspect:

  • Shift cam ①
  • Segment ②

Wear/damage → Replace.

3. Check:

- Shift fork movement

Unsmooth operation → Replace shift fork.

NOTE:

For a malfunctioning shift fork, replace not only the shift fork itself but the two gears each adjacent to the shift fork.

EC4H5000

ASSEMBLY AND INSTALLATION

Transmission

1. Install:

  • 5th pinion gear (27T) ①
  • 3rd pinion gear (21T) ②
  • Collar ③
  • 4th pinion gear (24T) ④
  • 2nd pinion gear (16T) ⑤

To main axle ⑥.

NOTE:

  • Apply the molybdenum disulfide oil on the 4th and 5th pinion gears inner circumference and on the end surface.
  • Apply the molybdenum disulfide oil on the 2nd and 3rd pinion gears inner circumference.
text_image New ① ② ③ a

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing gear and cam component with labeled parts (c, d)

YAMAHA WR250FP - NOTE: - 2

text_image B ①

2. Install:

  • 2nd wheel gear (28T) ①
  • 4th wheel gear (25T) ②
  • 3rd wheel gear (28T) ③
  • 5th wheel gear (22T) ④
  • 1st wheel gear (31T) ⑤
  • O-ring ⑥ New To drive axle ⑦.

NOTE:

  • Apply the molybdenum disulfide oil on the 1st, 2nd and 3rd wheel gears inner circumference and on the end surface.
  • Apply the molybdenum disulfide oil on the 4th and 5th wheel gears inner circumference.
  • Apply the lithium soap base grease on the O-ring.

3. Install:

  • Washer ①
  • Circlip ② New

NOTE:

  • Be sure the circlip sharp-edged corner ⓐ is positioned opposite side to the washer and gear ⓑ.
  • Be sure the circlip end © is positioned at axle spline groove ⓐ.

4. Install:

- Collar ①

NOTE:

  • Apply the lithium soap base grease on the oil seal lip.
  • When installing the collar into the crankcase, pay careful attention to the crankcase oil seal lip.

2. Monter:

text_image Technical diagram of a mechanical assembly with labeled parts, showing tool path and component layout

YAMAHA WR250FP - Monter: - 1

natural_image Mechanical assembly diagram showing gear and shaft components (no text or labels)

5. Install:

  • Shift fork 1 (L) ①
  • Shift fork 2 (C) ②
  • Shift fork 3 (R) ③
  • Shift cam ④

To main axle and drive axle.

NOTE:

  • Apply the molybdenum disulfide oil on the shift fork grooves.
  • Mesh the shift fork #1 (L) with the 4th wheel gear ⑤ and #3 (R) with the 5th wheel gear ⑦ on the drive axle.
  • Mesh the shift fork #2 (C) with the 3rd pinion gear ⑥ on the main axle.

6. Install:

  • Transmission assembly ①
    To left crankcase ②.

NOTE:

Apply the engine oil on the bearings and guide bars.

7. Check:

  • Shifter operation
    • Transmission operation
    Unsmooth operation → Repair.

5. Monter:

  • Fourchette 1 (L) ①
  • Fourchette 2 (C) ②
  • Fourchette 3 (R) ③
  • Tambour ④

① Front wheel removal
③ Brake disc removal

② Wheel bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalFRONT WHEEL REMOVALHold the machine by placing the suitable stand under the engine.WARNINGSupport the machine securely so there is no danger of it falling over.
YAMAHA WR250FP - Monter: - 13↑1Trip meter cable1Only loosening.Only loosening.
2Brake hose cover1
3Bolt (brake hose holder)2
4Bolt (axle holder)4
5Nut (front wheel axle)1
6Front wheel axle1
7Front wheel1
8Trip meter gear unit1
9Collar1
10Oil seal1
11Bearing2Refer to “REMOVAL POINTS”.
12Brake disc1

PARTIE CYCLE

ROUE AVANT ET ROUE ARRIERE

ROUE AVANT

Extent of removal:
① Rear wheel removal
③ Brake disc removal
② Wheel bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalREAR WHEEL REMOVALHold the machine by placing the suitable stand under the engine.WARNINGSupport the machine securely so there is no danger of it falling over.
1231Nut (rear wheel axle)1Refer to “REMOVAL POINTS”.
2Rear wheel axle1
3Drive chain puller2
4Rear wheel1
5Collar2
6Rear wheel sprocket1
7Oil seal2
8Circlip1
9Bearing2Refer to “REMOVAL POINTS”.
10Brake disc1

ROUE AVANT ET ROUE ARRIERE

VORDER- UND HINTERRAD

RUOTA ANTERIORE E RUOTA POSTERIORE

CHAS

YAMAHA WR250FP - RUOTA ANTERIORE E RUOTA POSTERIORE - 1

ROUE ARRIERE

text_image Technical diagram of a mechanical gear system with labeled components and motion indicators

YAMAHA WR250FP - ROUE ARRIERE - 1

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②, showing components like bolts, springs, and a central housing.

YAMAHA WR250FP - ROUE ARRIERE - 2

text_image Technical diagram showing mechanical device and cross-section with labeled components

YAMAHA WR250FP - ROUE ARRIERE - 3

natural_image Technical line drawing of two mechanical bearing assemblies with no visible text or symbols

EC593000

REMOVAL POINTS

EC523101

Rear wheel

  1. Remove:

- Wheel ①

NOTE:

Push the wheel forward and remove the drive chain ②.

EC513201

Wheel bearing (if necessary)

  1. Remove:

- Bearing ①

NOTE:

Remove the bearing using a general bearing puller ②.

EC594000

INSPECTION

EC514100

Wheel

  1. Measure:

- Wheel runout

Out of limit → Repair/replace.

YAMAHA WR250FP - Wheel - 1

Wheel runout limit:

Radial ①: 2.0 mm (0.08 in)

Lateral ②: 2.0 mm (0.08 in)

  1. Inspect:

- Bearing

Rotate inner race with a finger.

Rough spot/seizure → Replace.

NOTE:

Replace the bearings, oil seal and wheel collar as a set.

POINTS DE DEPOSE

Roue arrière

  1. Déposer:

- Roue ①

N.B.:

text_image Technical diagram showing a dial indicator measuring a mechanical setup with labeled component 1 and directional arrow.

EC514200

Wheel axle

1. Measure:

- Wheel axle bends

Out of specification → Replace.

Use the dial gauge ①.

YAMAHA WR250FP - Measure: - 1

Wheel axle bending limit: 0.5 mm (0.020 in)

NOTE:

The bending value is shown by one half of the dial gauge reading.

YAMAHA WR250FP - NOTE: - 1

WARNING

Do not attempt to straighten a bent axle.

YAMAHA WR250FP - WARNING - 1

text_image a ① 12210203

EC594200

Brake disc

1. Measure:

- Brake disc deflection (only rear brake disc)

Use the dial gauge ①.

Out of specification → Inspect wheel runout.

If wheel runout is in good condition, replace the brake disc.

YAMAHA WR250FP - Measure: - 1

Brake disc deflection limit:

Rear:

: 0.15 mm (0.006 in)

2. Measure:

- Brake disc thickness ⓐ

Out of limit → Replace.

YAMAHA WR250FP - Measure: - 1

Brake disc thickness:

Front:

3.0 mm (0.12 in)

: 2.5 mm (0.10 in)

Rear:

4.0 mm (0.16 in)

: 3.5 mm (0.14 in)

Axe de roue

  1. Mesurer:
text_image ① ② ③ ④ New

YAMAHA WR250FP - Axe de roue - 1

flowchart
graph TD
    1["①"] --> 2["②"]
    2 --> 3["③"]
    3 --> 4["④"]
    4 --> 5["⑤"]
    5 --> 6["⑥"]
    6 --> 1
    style 1 fill:#f9f,stroke:#333
    style 2 fill:#f9f,stroke:#333
    style 3 fill:#f9f,stroke:#333
    style 4 fill:#f9f,stroke:#333
    style 5 fill:#f9f,stroke:#333
    style 6 fill:#f9f,stroke:#333

YAMAHA WR250FP - Axe de roue - 2

text_image Technical diagram illustrating mechanical assembly steps with labeled parts and a magnified inset showing a mechanical component.

YAMAHA WR250FP - Axe de roue - 3

text_image Technical diagram of a mechanical component with labeled parts a and b, showing internal components and assembly lines.

EC595000

ASSEMBLY AND INSTALLATION

Front wheel

  1. Install:

  2. Bearing (left) ①

  3. Spacer ②
  4. Bearing (right) ③
  5. Oil seal ④ New

NOTE:

  • Apply the lithium soap base grease on the bearing and oil seal lip when installing.
  • Use a socket that matches the outside diameter of the race of the bearing.
  • Left side of bearing shall be installed first.
  • Install the oil seal with its manufacture's marks or numbers facing outward.

CAUTION:

Do not strike the inner race of the bearing. Contact should be made only with the outer race.

  1. Install:

  2. Brake disc ①

  3. Bolt (brake disc) ②

YAMAHA WR250FP - CAUTION: - 1

12 Nm (1.2 m · kg, 8.7 ft · lb)

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

  1. Install:

- Collar ①

NOTE:

  • Apply the lithium soap base grease on the oil seal lip.
  • Install the collar with their projection ⓐ facing the wheel.

  • Install:

- Trip meter gear unit ①

NOTE:

Make sure the two projections ⓐ in the wheel hub are meshed with the two slots ⓑ in the trip meter gear unit.

REMONTAGE ET MONTAGE

Roue avant

text_image Technical diagram of a mechanical assembly with labeled parts a and b

YAMAHA WR250FP - Roue avant - 1

text_image Technical diagram of a mechanical assembly with labeled parts and a scale indicator

YAMAHA WR250FP - Roue avant - 2

text_image Technical diagram showing mechanical assembly with labeled component '1'

YAMAHA WR250FP - Roue avant - 3

text_image Technical diagram of a mechanical component with labeled parts ①

YAMAHA WR250FP - Roue avant - 4

natural_image Line drawing of a motorcycle's front wheel and side gear assembly (no text or symbols)

5. Install:

- Wheel

NOTE:

  • Install the brake disc between the brake pads correctly.
  • Make sure that the projections ⓐ in the trip meter gear unit fits over the stopper ⓑ on the front fork outer tube.

6. Install:

- Wheel axle ①

NOTE:

Apply the lithium soap base grease on the wheel axle.

7. Install:

- Nut (wheel axle) ①

105 Nm (10.5 m · kg, 75 ft · lb)

8. Tighten:

- Bolt (axle holder) ①

23 Nm (2.3 m · kg, 17 ft · lb)

NOTE:

Before tightening the bolt, fit the wheel axle to the axle holder by stroking the front fork several times with the front brake applied.

ROUE AVANT ET ROUE ARRIERE

VORDER- UND HINTERRAD

RUOTA ANTERIORE E RUOTA POSTERIORE

CHAS

YAMAHA WR250FP - RUOTA ANTERIORE E RUOTA POSTERIORE - 1

5. Monter:

- Roue

N.B.:

text_image Technical diagram of a mechanical assembly with labeled parts (a, b, ①, ②) showing components like springs and levers.

9. Install:

- Brake hose ①

10 Nm (1.0 m · kg, 7.2 ft · lb)

To brake hose holder ②.

NOTE:

Before tightening the bolt (brake hose holder), pass the brake hose in front of the axle boss ①, then fit it into the hose groove ② so that the brake hose does not contact the nut (wheel axle).

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

10. Install:

  • Brake hose cover ①
  • Washer ②
  • Bolt [brake hose cover (M8)] ③

16 Nm (1.6 m · kg, 11 ft · lb)

- Bolt [brake hose cover (M6)] ④

7 Nm (0.7 m · kg, 5.1 ft · lb)

YAMAHA WR250FP - Install: - 1

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

11. Install:

- Trip meter cable ①

ROUE AVANT ET ROUE ARRIERE

VORDER- UND HINTERRAD

RUOTA ANTERIORE E RUOTA POSTERIORE

CHAS

YAMAHA WR250FP - RUOTA ANTERIORE E RUOTA POSTERIORE - 1

9. Monter:

- Tuyau de frein ①

10 Nm (1,0 m · kg, 7,2 ft · lb)

  • Bearing (right) ①
  • Circlip ② New
  • Spacer ③
  • Bearing (left) ④
  • Oil seal ⑤ New

NOTE:

  • Apply the lithium soap base grease on the bearing and oil seal lip when installing.
    • Install the bearing with seal facing outward.
  • Use a socket that matches the outside diameter of the race of the bearing.
  • Right side of bearing shall be installed first.
  • Install the oil seal with its manufacture's marks or numbers facing outward.

CAUTION:

Do not strike the inner race of the bearing. Contact should be made only with the outer race.

YAMAHA WR250FP - CAUTION: - 1

text_image Technical diagram of a mechanical component with numbered parts and directional arrows indicating motion or assembly.

YAMAHA WR250FP - CAUTION: - 2

text_image Diagram illustrating a mechanical gear system with numbered components and directional arrows indicating motion or force.

2. Install:

  • Brake disc ①
  • Bolt (brake disc) ②

YAMAHA WR250FP - Install: - 1

14 Nm (1.4 m · kg, 10 ft · lb)

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

3. Install:

  • Rear wheel sprocket ①
  • Bolt (rear wheel sprocket) ②
  • Washer (rear wheel sprocket) ③
  • Nut (rear wheel sprocket) ④

42 Nm (4.2 m · kg, 30 ft · lb)

NOTE:

Tighten the nuts in stage, using a crisscross pattern.

Roue arrière

text_image Technical diagram showing a hand operating a gear mechanism with labeled parts and a tool symbol B

YAMAHA WR250FP - Roue arrière - 1

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②

YAMAHA WR250FP - Roue arrière - 2

text_image Technical diagram showing a mechanical assembly with labeled components, including chain links and gear mechanism.

YAMAHA WR250FP - Roue arrière - 3

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

YAMAHA WR250FP - Roue arrière - 4

text_image Technical diagram of a mechanical assembly with numbered components labeled 1, 2, and 3.

4. Install:

- Collar ①

NOTE:

Apply the lithium soap base grease on the oil seal lip.

5. Install:

- Wheel

NOTE:

Install the brake disc ① between the brake pads ② correctly.

6. Install:

- Drive chain ①

NOTE:

Push the wheel ② forward and install the drive chain.

7. Install:

  • Left drive chain puller ①
  • Wheel axle ②

NOTE:

  • Install the left drive chain puller, and insert the wheel axle from left side.
  • Apply the lithium soap base grease on the wheel axle.

8. Install:

  • Right drive chain puller ①
  • Washer ②
  • Nut (wheel axle) ③

NOTE:

Temporarily tighten the nut (wheel axle) at this point.

ROUE AVANT ET ROUE ARRIERE

VORDER- UND HINTERRAD

RUOTA ANTERIORE E RUOTA POSTERIORE

CHAS

YAMAHA WR250FP - RUOTA ANTERIORE E RUOTA POSTERIORE - 1

4. Monter:

- Collerette ①

N.B.:

text_image Technical diagram showing mechanical assembly with labeled parts and directional arrow

YAMAHA WR250FP - N.B.: - 1

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②

9. Adjust:

- Drive chain slack ⓐ

YAMAHA WR250FP - Adjust: - 1

Drive chain slack: 40 \~ 50 mm (1.6 \~ 2.0 in)

Refer to "DRIVE CHAIN SLACK ADJUSTMENT" section in the CHAPTER 3.

10. Tighten:

- Nut (wheel axle) ①

125 Nm (12.5 m · kg, 90 ft · lb)

- Locknut ②

ROUE AVANT ET ROUE ARRIERE

VORDER- UND HINTERRAD

RUOTA ANTERIORE E RUOTA POSTERIORE

CHAS

YAMAHA WR250FP - RUOTA ANTERIORE E RUOTA POSTERIORE - 1

9. Régler:

Extent of removal:
① Brake hose removal
③ Brake master cylinder removal

② Brake caliper removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalFRONT BRAKE REMOVALHold the machine by placing the suitable stand under the engine.Drain the brake fluid.⚠ WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “REMOVAL POINTS”.
YAMAHA WR250FP - Régler: - 11Brake hose cover1Only loosening.Remove when loosening the pad pin.Loosen when disassembling the caliper.
2Brake hose holder1
3Bolt (brake hose holder)2
4Union bolt2
5Brake hose1
6Pad pin plug1
7Pad pin1
8Brake caliper1
9Brake lever1
10Brake master cylinder bracket1
11Brake master cylinder1

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

FREIN AVANT ET FREIN ARRIERE

FREIN AVANT

Extent of removal:
① Brake caliper removal
③ Brake master cylinder removal
② Brake hose removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalREAR BRAKE REMOVALHold the machine by placing the suitable stand under the engine.Rear wheelDrain the brake fluid.⚠ WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “FRONT WHEEL AND REAR WHEEL” section.Refer to “REMOVAL POINTS”.
1234567891012345678910Pad pin plugPad pinBrake caliperBrake hose holderUnion boltBrake hoseBrake pedalReservoir tankReservoir hoseBrake master cylinder1112211111Remove when loosening the pad pin.Loosen when disassembling the caliper.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

FREIN ARRIERE

text_image 3Nm (0.3m·kg,2.2ft·lb) 18Nm (1.8m·kg,13ft·lb) 6Nm (0.6m·kg,4.3ft·lb) New 6Nm (0.6m·kg,4.3ft·lb) New 18Nm (1.8m·kg,13ft·lb) 3Nm (0.3m·kg,2.2ft·lb)

A Front
B Rear
Extent of removal:
① Front brake caliper disassembly
② Rear brake caliper disassembly

Extent of removalOrderPart nameQ'tyRemarks
BRAKE CALIPER DISASSEMBLYAB
1 Pad pin11
2 Brake pad22
3 Pad support11
4 Brake caliper piston21Refer to “REMOVAL POINTS”.
5 Dust seal21Refer to “REMOVAL POINTS”.
6 Piston seal21

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

DEMONTAGE DE L'ETRIER

A Avant
B Arrière

A Front
B Rear
Extent of removal:
① Front brake master cylinder disassembly
② Rear brake master cylinder disassembly

Extent of removalOrderPart nameQ'tyRemarks
YAMAHA WR250FP - DEMONTAGE DE L'ETRIER - 111234567BRAKE MASTER CYLINDER DISASSEMBLYBrake master cylinder capDiaphragmBrake master cylinder bootCirclipWasherPush rodBrake master cylinder kit111111Use a long nose circlip pliers.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

DEMONTAGE DU MAITRE-CYLINDRE DE FREIN

A Avant
B Arrière

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - DEMONTAGE DU MAITRE-CYLINDRE DE FREIN - 1

text_image B ① ② - UPPER - LOWER

YAMAHA WR250FP - DEMONTAGE DU MAITRE-CYLINDRE DE FREIN - 2

text_image A ① ② B ① ②

YAMAHA WR250FP - DEMONTAGE DU MAITRE-CYLINDRE DE FREIN - 3

natural_image Line drawing of a hand using a tool to adjust or install a mechanical component (no text or symbols present)

YAMAHA WR250FP - DEMONTAGE DU MAITRE-CYLINDRE DE FREIN - 4

natural_image Line drawing of a hand using a tool to adjust or install a mechanical component (no text or symbols present)

EC5A3000

REMOVAL POINTS

Brake fluid

  1. Remove:

[Front]

  • Brake master cylinder cap ① [Rear]
  • Brake master cylinder guard ①
  • Reservoir tank cap ②

NOTE:

Do not remove the diaphragm.

A Front
B Rear

  1. Connect the transparent hose ② to the bleed screw ① and place a suitable container under its end.

A Front
B Rear

  1. Loosen the bleed screw and drain the brake fluid while pulling the lever in or pushing down on the pedal.

CAUTION:

  • Do not reuse the drained brake fluid.
  • Brake fluid may erode painted surfaces or plastic parts. Always clean up spilled fluid immediately.

Brake caliper piston

  1. Remove:

- Brake caliper piston

Use compressed air and proceed carefully.

WARNING

  • Cover piston with rag and use extreme caution when expelling piston from cylinder.
  • Never attempt to pry out piston.

Caliper piston removal steps:

  • Insert a piece of rag into the brake caliper to lock one brake caliper.
  • Carefully force the piston out of the brake caliper cylinder with compressed air.

A Front
B Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

POINTS DE DEPOSE

Liquide de frein

  1. Déposer:

[Arrière]

text_image A ① ② ② ①

YAMAHA WR250FP - Liquide de frein - 1

text_image B ① ②

YAMAHA WR250FP - Liquide de frein - 2

text_image A B a a

YAMAHA WR250FP - Liquide de frein - 3

text_image A ① B ①

YAMAHA WR250FP - Liquide de frein - 4

text_image A ① ② B ② ①

Brake caliper piston seal kit

1. Remove:

  • Dust seal ①
  • Piston seal ②

NOTE: ____

Remove the piston seals and dust seals by pushing them with a finger.

CAUTION:

Never attempt to pry out piston seals and dust seals.

WARNING

Replace the piston seals and dust seals whenever a caliper is disassembled.

A Front
B Rear

EC5A4000

INSPECTION

Brake master cylinder

1. Inspect:

- Brake master cylinder inner surface @ Wear/scratches → Replace master cylinder assembly. Stains → Clean.

WARNING

Use only new brake fluid.

A Front
B Rear

2. Inspect:

- Diaphragm ① Crack/damage → Replace.

A Front
B Rear

3. Inspect:

- Brake master cylinder piston ① - Brake master cylinder cup ② Wear/damage/score marks → Replace brake master cylinder kit.

A Front
B Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

text_image Technical diagram showing three labeled components: a cylindrical part, two ring rings, and a separate circular component with numbered annotations.

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

natural_image Diagram of a curved cable or connector with labeled points (1), no text or symbols present

Brake caliper

1. Inspect:

- Brake caliper cylinder inner surface @ Wear/score marks → Replace brake caliper assembly.

A Front

B Rear

2. Inspect:

- Brake caliper piston ① Wear/score marks → Replace brake caliper piston assembly.

WARNING

Replace the piston seals and dust seals ② whenever a caliper is disassembled.

EC534301

Brake hose

1. Inspect:

- Brake hose ① Crack/damage → Replace.

EC5A5000

ASSEMBLY AND INSTALLATION

WARNING

  • All internal parts should be cleaned in new brake fluid only.
  • Internal parts should be lubricated with brake fluid when installed.
  • Replace the piston seals and dust seals whenever a caliper is disassembled.

Brake caliper piston

1. Clean:

  • Brake caliper
  • Piston seal
  • Dust seal
  • Brake caliper piston Clean them with brake fluid.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

Etrier de frein

1. Contrôler:

text_image A ① ① New ② ② New

YAMAHA WR250FP - Contrôler: - 1

text_image B ① New ② New

YAMAHA WR250FP - Contrôler: - 2

text_image A ① ① a

YAMAHA WR250FP - Contrôler: - 3

text_image B ① ② ①

YAMAHA WR250FP - Contrôler: - 4

text_image Technical diagram of a mechanical assembly with numbered parts and labeled parts (a, b, ①, ②, ③)

2. Install:

- Piston seal ①

New

- Dust seal ②

New

WARNING

Always use new piston seals and dust seals.

NOTE:

Fit the piston seals and dust seals onto the slot on brake caliper correctly.

A Front

B Rear

3. Install:

- Brake caliper piston ①

NOTE:

Apply the brake fluid on the piston wall.

CAUTION:

- For the front brake caliper, install the piston with its depressed side ⓐ facing the brake caliper. For the rear brake caliper, install the piston with its shallow depressed side ⓑ facing the caliper.

- Never force to insert.

A Front

B Rear

Front brake caliper

1. Install:

- Pad support ①

- Brake pad ②

- Pad pin ③

NOTE:

- Install the brake pads with their projections ① into the brake caliper recesses ⑥.

- Temporarily tighten the pad pin at this point.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

  1. Monter:

- Joint de piston ①

New

- Joint antipoussière

New

! AVERTISSEMENT

text_image Technical diagram of a mechanical assembly with labeled parts a and b

YAMAHA WR250FP - ! AVERTISSEMENT - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

2. Install:

• Copper washer ① New
- Union bolt ②

30 Nm (3.0 m · kg, 22 ft · lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose so that its pipe portion ⓐ directs as show and lightly touches the projection ⓑ on the brake caliper.

3. Install:

  • Brake hose holder ①
  • Brake caliper ②
  • Bolt (brake caliper) ③

23 Nm (2.3 m · kg, 17 ft · lb)

NOTE:

Fit the brake hose holder cut ⓐ over the projection ⓑ on the front fork and clamp the brake hose.

4. Tighten:

- Pad pin ④

18 Nm (1.8 m · kg, 13 ft · lb)

5. Install:

- Pad pin plug ⑤

3 Nm (0.3 m · kg, 2.2 ft · lb)

YAMAHA WR250FP - Install: - 1

text_image Technical diagram of a mechanical assembly with numbered components and an inset view labeled a

Rear brake caliper

1. Install:

  • Pad support ①
  • Brake pad ②
  • Pad pin ③

NOTE:

  • Install the brake pads with their projections ① into the brake caliper recesses ②.
  • Temporarily tighten the pad pin at this point.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

  1. Monter:
text_image Technical diagram of a mechanical component with numbered parts labeled 1, 2, and 3.

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 2

text_image New ① ② ③ a

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 3

natural_image Technical line drawing of a mechanical assembly with labeled component (b), no readable text or symbols present

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 4

text_image Technical diagram of a mechanical assembly with numbered components for identification

2. Install:

  • Brake disc cover ①
  • Bolt (brake disc cover) ②

7 Nm (0.7 m · kg, 5.1 ft · lb)

3. Install:

  • Copper washer ①
    New
  • Brake hose ②
  • Union bolt ③

30 Nm (3.0 m · kg, 22 ft · lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose to the brake caliper with the paint ⓐ on the pipe facing the brake caliper and with the pipe contacting the brake caliper projection ⓑ.

4. Install:

  • Brake caliper ①
  • Rear wheel ②
    Refer to "FRONT WHEEL AND REAR WHEEL" section.

5. Tighten:

- Pad pin ③

18 Nm (1.8 m · kg, 13 ft · lb)

6. Install:

- Pad pin plug ④

3 Nm (0.3 m · kg, 2.2 ft · lb)

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

2. Monter:

Brake master cylinder kit

1. Clean:

  • Brake master cylinder
  • Brake master cylinder kit

Clean them with brake fluid.

YAMAHA WR250FP - Clean: - 1

text_image A ② ① ③ B ① ② ③

YAMAHA WR250FP - Clean: - 2

text_image A ② ① ③ B ① ② ③

YAMAHA WR250FP - Clean: - 3

text_image A ② ① B ② ①

2. Install:

  • Brake master cylinder cup (primary) ①
  • Brake master cylinder cup (secondary) ②
    To brake master cylinder piston ③.

NOTE: ____ Apply the brake fluid on the brake master cylinder cup.

WARNING

After installing, cylinder cup should be installed as shown direction. Wrong installation cause improper brake performance.

A Front
B Rear

3. Install:

  • Spring ①
    To brake master cylinder piston ②.

NOTE: ____ Install the spring at the smaller dia. side.

A Front
B Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

text_image A ⑤ ① ② ③ ④

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

text_image B ⑤ ① ② ③ ④ B

4. Install:

[Front]

  • Brake master cylinder kit ①
  • Washer ②
  • Circlip ③
  • Brake master cylinder boot ④ To brake master cylinder ⑤.

[Rear]

  • Brake master cylinder kit ①
  • Push rod ②
  • Circlip ③
  • Brake master cylinder boot ④ To brake master cylinder ⑤.

NOTE:

  • Apply the brake fluid on the brake master cylinder kit.
  • Apply the lithium soap base grease on the tip of the push rod.
  • When installing the circlip, use a long nose circlip pliers.

A Front

B Rear

YAMAHA WR250FP - NOTE: - 1

text_image ① ② ③ U P a

Front brake master cylinder

1. Install:

  • Brake master cylinder ①
  • Brake master cylinder bracket ②
  • Bolt (brake master cylinder bracket) ③

9 Nm (0.9 m · kg, 6.5 ft · lb)

NOTE:

  • Install the bracket so that the arrow mark ⓐ face upward.
  • First tighten the bolts on the upper side of the brake master cylinder bracket, and then tighten the bolts on the lower side.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

4. Monter:

[Avant]

text_image Technical diagram showing a hand operating a tool with labeled parts and a labeled component B

YAMAHA WR250FP - Monter: - 1

text_image ① ② - UPPER - LOWER ③

YAMAHA WR250FP - Monter: - 2

text_image Technical diagram of a mechanical assembly with numbered components, likely for assembly or maintenance reference.

YAMAHA WR250FP - Monter: - 3

text_image New ① ② ③ ④ B ⑤ a

2. Install:

  • Brake lever ①
  • Bolt (brake lever) ②

6 Nm (0.6 m · kg, 4.3 ft · lb)

- Nut (brake lever) ③

6 Nm (0.6 m · kg, 4.3 ft · lb)

NOTE:

Apply the lithium soap base grease on the brake lever sliding surface, bolt and contacting surface of the brake master cylinder piston.

Rear brake master cylinder

1. Install:

  • Reservoir hose ①
  • Reservoir tank ②
  • Bolt (reservoir tank) ③

10 Nm (1.0 m · kg, 7.2 ft · lb)

2. Install:

  • Brake master cylinder ①
  • Bolt (brake master cylinder) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

3. Install:

  • Spring ①
  • Brake pedal ②
  • O-ring ③ New
  • Bolt (brake pedal) ④

26 Nm (2.6 m · kg, 19 ft · lb)

- Clip ⑤

NOTE:

  • Apply the lithium soap base grease on the bolt, O-ring and brake pedal bracket.
  • Install the clip with its stopper portion ⓐ facing inward.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

2. Monter:

text_image Technical diagram showing a mechanical assembly with labeled parts and a 'New' label, likely illustrating a gear or fastening mechanism.

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram of a mechanical assembly with labeled parts (a, b, ①, ②)

4. Install:

  • Pin ①
  • Washer ②
  • Cotter pin ③

New

NOTE:

After installing, check the brake pedal height. Refer to “REAR BRAKE ADJUSTMENT” section in the CHAPTER 3.

Front brake hose

1. Install:

- Brake hose ①

10 Nm (1.0 m · kg, 7.2 ft · lb)

To brake hose holder ②.

NOTE:

Before tightening the bolt (brake hose holder), pass the brake hose in front of the axle boss ①, then fit it into the hose groove ② so that the brake hose does not contact the nut (wheel axle).

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical assembly with numbered components for identification

YAMAHA WR250FP - NOTE: - 2

text_image Technical diagram of a mechanical device with labeled parts, including components ①, ②, and ③.

2. Install:

  • Brake hose cover ①
  • Washer ②
  • Bolt [brake hose cover (M8)] ③

16 Nm (1.6 m · kg, 11 ft · lb)

- Bolt [brake hose cover (M6)] ④

7 Nm (0.7 m · kg, 5.1 ft · lb)

  1. Pass the brake hose through the cable guides ①, then through the guides @ on the protector ②.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

4. Monter:

- Goupille ①

- Rondelle ②

- Goupille fendue ③

New

N.B.:

text_image ① New ② ③

YAMAHA WR250FP - N.B.: - 1

text_image Technical diagram of a mechanical component with labeled parts a and b

YAMAHA WR250FP - N.B.: - 2

text_image ① New ③ New ④

YAMAHA WR250FP - N.B.: - 3

text_image a b c d

4. Install:

  • Copper washer ①
  • Brake hose ②
  • Union bolt ③

YAMAHA WR250FP - Install: - 1

30 Nm (3.0 m · kg, 22 ft · lb)

YAMAHA WR250FP - Install: - 2

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose so that it contacts the master cylinder projection ⓐ and that its bent portion ⓑ faces downward.

Rear brake hose

1. Install:

  • Copper washer ①
  • Brake hose ②
  • Copper washer ③
  • Union bolt ④

YAMAHA WR250FP - Install: - 1

YAMAHA WR250FP - Install: - 2

YAMAHA WR250FP - Install: - 3

30 Nm (3.0 m · kg, 22 ft · lb)

WARNING

Always use new copper washers.

CAUTION:

When installing the brake hose, first align the tooth ⓐ on the copper washer ① with the projection ⓑ on the brake master cylinder. Then, align the pipe portion Ⓒ on the end of the brake hose with the tooth ⓓ on the copper washer ① and tighten the union bolt.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

  1. Monter:
natural_image Line drawing of a mechanical assembly with gears and a magnified inset showing internal components (no text or symbols)

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 2

text_image A a T UP

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 3

text_image B - UPPER - LOWER a

2. Install:

  • Brake hose holder ①
  • Screw (brake hose holder) ②

YAMAHA WR250FP - Install: - 1

1 Nm (0.1 m · kg, 0.7 ft · lb)

CAUTION:

After installing the brake hose holders, make sure the brake hose does not contact the spring (rear shock absorber). If it does, correct its twist.

Brake fluid

1. Fill:

  • Brake fluid
    Until the fluid level reaches “LOWER” level line ⓐ.

YAMAHA WR250FP - Fill: - 1

Recommended brake fluid: DOT #4

WARNING

  • Use only the designated quality brake fluid:
    otherwise, the rubber seals may deteriorate, causing leakage and poor brake performance.
  • Refill with the same type of brake fluid; mixing fluids may result in a harmful chemical reaction and lead to poor performance.
  • Be careful that water does not enter the master cylinder when refilling. Water will significantly lower the boiling point of the fluid and may result in vapor lock.

CAUTION:

Brake fluid may erode painted surfaces or plastic parts. Always clean up spilled fluid immediately.

A Front
B Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

2. Monter:

Fluid at lower level → Fill up.

Refer to “BRAKE FLUID LEVEL INSPECTION” section in the CHAPTER 3.

YAMAHA WR250FP - Monter: - 1

text_image A ① ②

YAMAHA WR250FP - Monter: - 2

text_image B ① - UPPER - LOWER ②

YAMAHA WR250FP - Monter: - 3

text_image Technical diagram of a mechanical assembly with numbered components, likely illustrating a vehicle or mechanical assembly.

4. Install:

[Front]

  • Diaphragm
  • Brake master cylinder cap ①
  • Screw (brake master cylinder cap) ②

2 Nm (0.2 m · kg, 1.4 ft · lb)

[Rear]

  • Diaphragm
  • Reservoir tank cap ①
  • Screw (reservoir tank cap) ②

2 Nm (0.2 m · kg, 1.4 ft · lb)

- Brake master cylinder guard

10 Nm (1.0 m · kg, 7.2 ft · lb)

CAUTION:

After installation, while pulling the brake lever in or pushing down on the brake pedal, check whether there is any brake fluid leaking where the union bolts are installed respectively at the brake master cylinder and brake caliper.

A Front
B Rear

  1. Install: (rear brake only)

  2. Protector ①

  3. Bolt (protector) ②

7 Nm (0.7 m · kg, 5.1 ft · lb)

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE

YAMAHA WR250FP - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO ANTERIORE E POSTERIORE - 1

2. Purger l'air:

- Circuit de freinage Se reporter à la section "PURGE D'AIR DU CIRCUIT DE FREINAGE" du CHAPITRE 3.

2. Entlüften:

Extent of removal:
① Front fork removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalFRONT FORK REMOVALHold the machine by placing the suitable stand under the engine.⚠ WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “FRONT WHEEL AND REAR WHEEL” section.Refer to “FRONT BRAKE AND REAR BRAKE” section.Refer to “HANDLEBAR” section.
Front wheel
Front brake caliper
Headlight
Handlebar
11Protector1
2Brake hose holder2
3Pinch bolt (upper bracket)2Only loosening.
4Cap bolt1Loosen when disassembling the front fork.
5Pinch bolt (lower bracket)2Only loosening.
6Front fork1

FOURCHE AVANT

Extent of removal:
① Oil seal removal
② Damper rod removal

Extent of removalOrderPart nameQ'tyRemarks
YAMAHA WR250FP - FOURCHE AVANT - 112345678910111213FRONT FORK DISASSEMBLYFront fork cap boltFork springDust sealStopper ringInner tubeOuter tubePiston metalSlide metalOil seal washerOil sealSpring guideBase valveDamper rod1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111Refer to “REMOVAL POINTS”.Drain the fork oil.Refer to “REMOVAL POINTS”.Use special tool.Refer to “REMOVAL POINTS”.

DEMONTAGE DE LA FOURCHE AVANT

The front fork requires careful attention. So it is recommended that the front fork be maintained at the dealers.

CAUTION:

To prevent an accidental explosion of air, the following instructions should be observed:

  • The front fork with a built-in piston rod has a very sophisticated internal construction and is particularly sensitive to foreign material.
    Use enough care not to allow any foreign material to come in when the oil is replaced or when the front fork is disassembled and reassembled.
  • Before removing the cap bolts or front forks, be sure to extract the air from the air chamber completely.

YAMAHA WR250FP - CAUTION: - 1

text_image Diagram showing a hand holding a cylindrical object with a labeled step number 1 pointing to the component.

YAMAHA WR250FP - CAUTION: - 2

text_image Technical diagram of a mechanical spring assembly with numbered parts labeled 1 to 5

EC553000

REMOVAL POINTS

Front fork cap bolt

  1. Remove:

- Front fork cap bolt ①

From the outer tube.

NOTE:

Before removing the front fork from the machine, loosen the front fork cap bolt.

  1. Remove:

- Front fork cap bolt ①

NOTE:

  • While compressing the fork spring, set the thin type spanners ② between the spacer ③ and spring guide ④.
  • Hold the locknut ⑤ and remove the front fork cap bolt.

REMARQUES CONCERNANT LA MANIPULATION

N.B.:

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②

YAMAHA WR250FP - N.B.: - 1

text_image Diagram illustrating a mechanical or electrical device with labeled parts (a, b) and numbered component (1), showing hand positioning and movement.

YAMAHA WR250FP - N.B.: - 2

text_image Technical diagram of a mechanical assembly with numbered components labeled ①, ②, and ③.

YAMAHA WR250FP - N.B.: - 3

natural_image Line drawing of a mechanical component with a threaded end and labeled part 1 (no text or symbols beyond label)

EC553201

Inner tube

1. Remove:

  • Dust seal ①
  • Stopper ring ②

Using slotted-head screwdriver.

CAUTION:

Take care not to scratch the inner tube.

2. Remove:

- Inner tube ①

Oil seal removal steps:

  • Push in slowly ⓐ the inner tube just before it bottoms out and then pull it back quickly ⓑ.
  • Repeat this step until the inner tube can be pulled out from the outer tube.

EC553311

Damper rod

1. Remove:

  • Base valve ①
  • Damper rod ②

NOTE:

Use a damper rod holder ③ to lock the damper rod.

YAMAHA WR250FP - NOTE: - 1

Damper rod holder: YM-1423/90890-01423

EC554000

INSPECTION

EC554100

Damper rod

1. Inspect:

- Damper rod ①

Bend/damage → Replace damper rod.

CAUTION:

The front fork with a built-in piston rod has a very sophisticated internal construction and is particularly sensitive to foreign material.

Use enough care not to allow any foreign material to come in when the oil is replaced or when the front fork is disassembled and reassembled.

Tube interne

text_image Technical diagram of a mechanical component with numbered parts labeled ① and ②

YAMAHA WR250FP - Tube interne - 1

natural_image Diagram of a coiled spring with labeled dimension (a), no text or symbols present

YAMAHA WR250FP - Tube interne - 2

text_image Technical diagram of a mechanical device with labeled parts ① and ②, showing components like a dial indicator and lever mechanism.

YAMAHA WR250FP - Tube interne - 3

natural_image Line drawing of a cylindrical pipe with a labeled end (1), no text or symbols present

EC554200

Base valve

1. Inspect:

  • Valve assembly ① Wear/damage → Replace.
  • O-ring ② Damage → Replace.

EC554400

Fork spring

1. Measure:

  • Fork spring free length ⓐ Out of specification → Replace.

YAMAHA WR250FP - Measure: - 1

Fork spring free length: 460 mm (18.1 in) : 455 mm (17.9 in)

EC554502

Inner tube

1. Inspect:

  • Inner tube surface ⓐ Score marks → Repair or replace. Use #1,000 grit wet sandpaper. Damaged oil lock piece → Replace.
  • Inner tube bends Out of specification → Replace. Use the dial gauge ①.

YAMAHA WR250FP - Inspect: - 1

Inner tube bending limit: 0.2 mm (0.008 in)

NOTE:

The bending value is shown by one half of the dial gauge reading.

YAMAHA WR250FP - NOTE: - 1

WARNING

Do not attempt to straighten a bent inner tube as this may dangerously weaken the tube.

EC554600

Outer tube

1. Inspect:

  • Outer tube ①
    Score marks/wear/damage → Replace.

Soupape de base

1. Contrôler:

  • Ensemble clapet ① Usure/endommagement → Remplacer.

- Joint torque ② Endommagement → Rempla- cer.

Luftventil

1. Kontrollieren:

text_image Technical diagram of a mechanical component with numbered parts and dimension annotations

Front fork cap bolt

1. Inspect:

  • Front fork cap bolt ①
  • O-ring ②
  • Air bleed screw ③

Wear/damage → Replace.

EC555000

ASSEMBLY AND INSTALLATION

Front fork assembly

  1. Wash the all parts in a clean solvent.

YAMAHA WR250FP - Front fork assembly - 1

text_image Technical diagram of a mechanical device with labeled parts, showing two components and their assembly.

2. Install:

- Damper rod ①

To inner tube ②.

CAUTION:

To install the damper rod into the inner tube, hold the inner tube aslant. If the inner tube is held vertically, the damper rod may fall into it, damaging the valve inside.

YAMAHA WR250FP - CAUTION: - 1

text_image ④ ③ ① New ②

3. Install:

YAMAHA WR250FP - Install: - 1

  • Copper washer ①
  • O-ring ②
  • Base valve ③

To inner tube ④.

4. Tighten:

- Base valve ①

YAMAHA WR250FP - Tighten: - 1

55 Nm (5.5 m · kg, 40 ft · lb)

YAMAHA WR250FP - Tighten: - 2

text_image Technical diagram of a mechanical device with numbered components labeled ①, ②, and ③.

NOTE:

  • Use a damper rod holder ② to lock the damper rod ③.
  • Apply the LOCTITE® on the base valve thread.

YAMAHA WR250FP - NOTE: - 1

Damper rod holder: YM-1423/90890-01423

text_image Technical diagram of a mechanical assembly with labeled parts and an inset showing a cross-section view labeled 'b'.

YAMAHA WR250FP - NOTE: - 2

text_image New ① ② ③ ④ ⑤ New ⑥

YAMAHA WR250FP - NOTE: - 3

text_image ③ ① I2311310

YAMAHA WR250FP - NOTE: - 4

text_image ① New

YAMAHA WR250FP - NOTE: - 5

text_image Technical diagram of a mechanical component with labeled parts ① and ②

5. Install:

  • Spring guide ①
  • Locknut ②

To damper rod ③.

NOTE:

  • Install the spring guide with its cut ⓐ facing upward.
  • With its thread ⑥ facing upward, fully finger tighten the locknut onto the damper rod.

6. Install:

  • Dust seal ①
  • Stopper ring ②
  • Oil seal ③ New
  • Oil seal washer ④
  • Slide metal ⑤ New
    To inner tube ⑥.

NOTE:

  • Apply the fork oil on the inner tube.
  • When installing the oil seal, use vinyl seat ⓐ with fork oil applied to protect the oil seal lip.
  • Install the oil seal with its manufacture's marks or number facing the axle holder side.

7. Install:

- Piston metal ① New

NOTE:

Install the piston metal onto the slot on inner tube.

8. Install:

  • Outer tube ①
    To inner tube ②.

5. Monter:

text_image Technical diagram of a pipe joint with labeled components ① and ②

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram showing a hand operating a mechanical component with labeled part 3

YAMAHA WR250FP - Monter: - 2

text_image Technical diagram showing a hand operating a mechanical component with labeled parts ① and ②

YAMAHA WR250FP - Monter: - 3

natural_image Technical line drawing of a mechanical joint or pipe connection (no text or symbols)

YAMAHA WR250FP - Monter: - 4

text_image Technical diagram showing a pipe connection with labeled component B and numbered point 1

9. Install:

  • Slide metal ①
  • Oil seal washer ②
    To outer tube slot.

NOTE:

Press the slide metal into the outer tube with fork seal driver ③.

YAMAHA WR250FP - NOTE: - 1

Fork seal driver: YM-01442/90890-01442

10. Install:

- Oil seal ①

NOTE:

Press the oil seal into the outer tube with fork seal driver ②.

YAMAHA WR250FP - NOTE: - 1

Fork seal driver: YM-01442/90890-01442

11. Install:

- Stopper ring ①

NOTE:

Fit the stopper ring correctly in the groove in the outer tube.

12. Install:

- Dust seal ①

NOTE:

Apply the lithium soap base grease on the inner tube.

9. Monter:

natural_image Line drawing of a hand holding a mechanical component with directional arrows indicating movement (no text or symbols)

YAMAHA WR250FP - Monter: - 1

text_image

13. Check:

- Inner tube smooth movement Tightness/binding/rough spots → Repeat the steps 2 to 12.

14. Compress the front fork fully.

15. Fill:

- Front fork oil Until outer tube top surface with recommended fork oil ①.

YAMAHA WR250FP - Fill: - 1

CAUTION:

  • Be sure to use recommended fork oil. If other oils are used, they may have an excessively adverse effect on the front fork performance.
  • Never allow foreign materials to enter the front fork.

YAMAHA WR250FP - CAUTION: - 1

text_image Diagram showing a hand operating a cylindrical device with a labeled component and directional arrow indicating movement or force.

YAMAHA WR250FP - CAUTION: - 2

text_image Technical diagram showing a hand holding a mechanical component with labeled part 1 and directional arrow indicating movement.
  1. After filling, pump the damper rod ① slowly up and down more than 10 times to distribute the fork oil.

17. Fill:

- Front fork oil Until outer tube top surface with recommended fork oil once more.

  1. After filling, pump the outer tube ① slowly up and down (about 200 mm (7.9 in) stroke) to distribute the fork oil once more.

NOTE:

Be careful not to excessive full stroke. A stroke of 200 mm (7.9 in) or more will cause air to enter. In this case, repeat the steps 15 to 18.

13. Contrôler:

  1. Wait ten minutes until the air bubbles have been removed from the front fork, and the oil has dispense evenly in system before setting recommended oil level.

NOTE:

Fill with the fork oil up to the top end of the outer tube, or the fork oil will not spread over to every part of the front forks, thus making it impossible to obtain the correct level.

Be sure to fill with the fork oil up to the top of the outer tube and bleed the front forks.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram of a mechanical device with labeled components and dimensional annotations

311404

20. Measure:

- Oil level (left and right) ⓐ

Out of specification → Adjust.

YAMAHA WR250FP - Measure: - 1

Standard oil level:

140 mm (5.51 in)

* 130 mm (5.12 in)

Extent of adjustment:

80 \~ 150 mm (3.15 \~ 5.91 in)

From top of outer tube with inner tube and damper rod ①

fully compressed without spring.

* For EUROPE

NOTE:

Be sure to install the spring guide ② when checking the oil level.

WARNING

Never fail to make the oil level adjustment between the maximum and minimum level and always adjust each front fork to the same setting. Uneven adjustment can cause poor handling and loss of stability.

text_image Technical diagram of a mechanical component with numbered parts labeled 1 to 4

YAMAHA WR250FP - WARNING - 1

text_image Diagram showing a hand holding a coiled spring with labeled parts ①, ②, and ③

YAMAHA WR250FP - WARNING - 2

natural_image Technical line drawing of a mechanical spring component with threaded shaft and mounting base (no text or symbols)

21. Measure:

- Distance ⓐ

Out of specification → Turn into the locknut.

YAMAHA WR250FP - Measure: - 1

Distance ⓐ:

20 mm (0.79 in) or more

Between damper rod ① top and locknut ② top.

22. Loosen:

- Rebound damping adjuster ①

NOTE: \_\_\_\_

  • Loosen the rebound damping adjuster finger tight.
  • Record the set position of the adjuster (the amount of turning out the fully turned in position).

23. Install

  • Cushion rubber ①
  • Washer ②
  • Spacer ③
    To front fork cap bolt ④.

NOTE: \_\_\_\_

Install the cushion rubber with its smaller dia.end @ facing the front fork cap bolt.

24. Install:

  • Push rod ①
  • Fork spring ②

NOTE: \_\_\_\_

  • Install the fork spring with the damper rod ③ pulled up.
  • After installing the fork spring, hold the damper rod end so that it will not go down.

25. Install:

- Front fork cap bolt ① Fully tighten the front fork cap bolt onto the damper rod by hand.

21. Mesurer:

- Distance ⓐ

text_image Technical diagram of a mechanical spring assembly with numbered parts labeled 1 to 5

YAMAHA WR250FP - Mesurer: - 1

text_image Diagram showing a hand holding a cylindrical object with a numbered label pointing to it, likely illustrating a step in a procedure.

YAMAHA WR250FP - Mesurer: - 2

text_image

YAMAHA WR250FP - Mesurer: - 3

text_image Technical diagram of a mechanical assembly with labeled component ①

YAMAHA WR250FP - Mesurer: - 4

text_image Technical diagram showing mechanical assembly with labeled parts and directional arrows

26. Tighten:

- Front fork cap bolt (locknut) ①

29 Nm (2.9 m · kg, 21 ft · lb)

NOTE:

  • While compressing the fork spring, set the thin type spanners ② between the spacer ③ and spring guide ④.
  • Hold the locknut ⑤ and tighten the front fork cap bolt with specified torque.

27. Install:

- Front fork cap bolt ① To outer tube.

NOTE:

Temporarily tighten the cap bolt.

28. Install:

- Protector guide ①

Installation

1. Install:

- Front fork ①

NOTE:

  • Temporarily tighten the pinch bolts (lower bracket).
  • Do not tighten the pinch bolts (upper bracket) yet.

2. Tighten:

- Front fork cap bolt ①

30 Nm (3.0 m · kg, 22 ft · lb)

3. Adjust:

- Front fork top end ⓐ

YAMAHA WR250FP - Adjust: - 1

Front fork top end (standard) ⓐ: 5 mm (0.20 in)

* 8 mm (0.31 in)

** 10.5 mm (0.41 in)

* For EUROPE
** For AUS, NZ and ZA

  1. Serrer:
text_image Technical diagram of a mechanical assembly with numbered components, likely illustrating a gear or linkage mechanism.

YAMAHA WR250FP - Adjust: - 2

text_image Technical diagram of a mechanical assembly with numbered components labeled 1, 2, 3, and 4.

YAMAHA WR250FP - Adjust: - 3

text_image Technical diagram of a mechanical assembly with numbered components labeled 1 through 5

4. Tighten:

- Pinch bolt (upper bracket) ①

23 Nm (2.3 m · kg, 17 ft · lb)

- Pinch bolt (lower bracket) ②

Tighten the lower bracket to specified torque. If torqued too much, it may cause the front fork to malfunction.

5. Install:

  • Brake hose holder ①
  • Brake caliper ②
  • Bolt (brake caliper) ③

23 Nm (2.3 m · kg, 17 ft · lb)

NOTE:

Fit the brake hose holder cut ⓐ over the projection ⓑ on the front fork and clamp the brake hose.

6. Install:

  • Brake hose holder ①
  • Bolt (brake hose holder) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

  • Protector ③
  • Bolt (protector) ④

10 Nm (1.0 m · kg, 7.2 ft · lb)

NOTE:

When installing the brake hose holder, pass the brake hose ⑤ in front of the axle boss ⓐ, then fit it into the hose groove ⑥ so that the brake hose does not contact the nut (wheel axle).

YAMAHA WR250FP - NOTE: - 1

text_image S←H ①

7. Adjust:

- Rebound damping force

NOTE:

Turn in the damping adjuster ① finger-tight and then turn out to the originally set position.

4. Serrer:

Extent of removal:
① Handlebar removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalHANDLEBAR REMOVALHeadlight
11Decompression cable1Disconnect at the lever side.
2Decompression lever holder1
3Clutch cable1Disconnect at the lever side.
4Clutch lever holder1
5Engine stop switch1
6Light switch1
7Brake master cylinder1Refer to “REMOVAL POINTS”.
8Throttle cable cap1
9Throttle cable #2 (pushed)1Disconnect at the throttle side.
10Throttle cable #1 (pulled)1Disconnect at the throttle side.
11Right grip1Refer to “REMOVAL POINTS”.
12Tube guide1
13Grip cap cover1
14Collar1
15Left grip1Refer to “REMOVAL POINTS”.
16Handlebar upper holder2
17Handlebar1

GUIDON

Brake master cylinder

  1. Remove:

  2. Brake master cylinder bracket ①

  3. Brake master cylinder ②

CAUTION:

  • Do not let the brake master cylinder hang on the brake hose.
  • Keep the brake master cylinder cap side horizontal to prevent air from coming in.

YAMAHA WR250FP - CAUTION: - 1

text_image ① I2410201

EC5B3200

Grip

  1. Remove:

- Grip ①

NOTE:

Blow in air between the handlebar or tube guide and the grip. Then remove the grip which has become loose.

YAMAHA WR250FP - NOTE: - 1

natural_image Line drawing of a bent tool or bracket with a labeled component (no text or symbols present)

EC5B4000

INSPECTION

EC5B4100

Handlebar

  1. Inspect:

  2. Handlebar ①
    Bends/cracks/damage → Replace.

WARNING

Do not attempt to straighten a bent handlebar as this may dangerously weaken the handlebar.

POINTS DE DEPOSE

text_image Technical diagram showing three labeled components (①, ②, ③) of a mechanical or structural assembly with connecting rods.

YAMAHA WR250FP - POINTS DE DEPOSE - 1

text_image a FWD

YAMAHA WR250FP - POINTS DE DEPOSE - 2

text_image b R L ① ② a

YAMAHA WR250FP - POINTS DE DEPOSE - 3

text_image Technical diagram of a mechanical component with labeled parts ①, ②, and ③

YAMAHA WR250FP - POINTS DE DEPOSE - 4

text_image 90° b ① c ③

EC5B5000

ASSEMBLY AND INSTALLATION Handlebar

1. Install:

  • Handlebar ①
  • Handlebar upper holder ②
  • Bolt (handlebar upper holder) ③

YAMAHA WR250FP - Install: - 1

  • The handlebar upper holder should be installed with the punched mark @ forward.
  • First tighten the bolts on the front side of the handlebar upper holder, and then tighten the bolts on the rear side.

2. Install:

- Left grip ①

Apply the adhesive to the handlebar ②.

NOTE:

  • Before applying the adhesive, wipe off grease or oil on the handlebar surface ⓐ with a lacquer thinner.
  • Install the left grip to the handlebar so that the line ⑥ between the two arrow marks faces straight upward.

3. Install:

  • Right grip ①
  • Collar ②

Apply the adhesive on the tube guide ③.

NOTE:

  • Before applying the adhesive, wipe off grease or oil on the tube guide surface ① with a lacquer thinner.
  • Install the grip to the tube guide so that the grip match mark ⑥ and tube guide slot © form the angle as shown.

REMONTAGE ET MONTAGE

Guidon

text_image Technical diagram of a mechanical assembly with labeled parts ①, ②, and ③, showing a tool labeled B.

YAMAHA WR250FP - Guidon - 1

text_image Technical diagram of a mechanical assembly with labeled parts 1 and 2, and a valve B.

YAMAHA WR250FP - Guidon - 2

text_image Technical diagram of a mechanical assembly with numbered components, likely illustrating a welding or cutting process.

YAMAHA WR250FP - Guidon - 3

text_image Diagram of a mechanical or fluid system with labeled component ③ and directional arrows indicating flow or movement.

YAMAHA WR250FP - Guidon - 4

text_image Technical diagram of a cable connector with labeled parts ① and ②

4. Install:

  • Collar ①
  • Grip cap cover ②
  • Throttle grip ③

NOTE: \_\_\_\_

Apply the lithium soap base grease on the throttle grip sliding surface.

5. Install:

  • Throttle cables ①
    To tube guide ②.

NOTE: \_\_\_\_

Apply the lithium soap base grease on the throttle cable end and tube guide cable winding portion.

6. Install:

  • Throttle cable cap ①
  • Screw (throttle cable cap) ②

YAMAHA WR250FP - Install: - 1

4 Nm (0.4 m · kg, 2.9 ft · lb)

WARNING

After tightening the screws, check that the throttle grip ③ moves smoothly. If it does not, retighten the bolts for adjustment.

7. Install:

  • Grip cap cover ①
  • Cover (throttle cable cap) ②

4. Monter:

text_image ① ② ③ U P a

8. Install:

  • Brake master cylinder ①
  • Brake master cylinder bracket ②
  • Bolt (brake master cylinder bracket) ③

YAMAHA WR250FP - Install: - 1

9 Nm (0.9 m · kg, 6.5 ft · lb)

NOTE:

  • Install the bracket so that the arrow mark ⓐ faces upward.
  • First tighten the bolt on the upper side of the brake master cylinder bracket, and then tighten the bolt on the lower side.

YAMAHA WR250FP - NOTE: - 1

text_image 35 mm (1.38 in) ①

9. Install:

- Light switch ①

YAMAHA WR250FP - Install: - 1

2 Nm (0.2 m · kg, 1.4 ft · lb)

YAMAHA WR250FP - Install: - 2

text_image Technical diagram of a mechanical device with numbered components for identification

10. Install:

  • Engine stop switch ①
  • Clutch lever holder ②
  • Bolt (clutch lever holder) ③
  • Decompression lever holder ④
  • Clamp ⑥

YAMAHA WR250FP - Install: - 1

4 Nm (0.4 m · kg, 2.9 ft · lb)

- Bolt (decompression lever holder) ⑤

YAMAHA WR250FP - Install: - 2

4 Nm (0.4 m · kg, 2.9 ft · lb)

YAMAHA WR250FP - Install: - 3

text_image 12 mm (0.47 in) 7 mm (0.28 in) 4.5 ~ 6.5 mm (0.18 ~ 0.26 in) 30~50° FWD ←

NOTE:

  • The engine stop switch, clutch lever holder, decompression lever holder and clamp should be installed according to the dimensions shown.
  • Pass the engine stop switch lead in the middle of the clutch holder.

8. Monter:

text_image Technical diagram of a mechanical device with labeled parts, including lever and adjustment mechanism

11. Install:

  • Clutch cable ①
  • Decompression cable ②

NOTE:

Apply the lithium soap base grease on the clutch cable end and decompression cable end.

12. Adjust:

  • Clutch lever free play Refer to “CLUTCH ADJUSTMENT” section in the CHAPTER 3.
  • Decompression lever free play Refer to “DECOMPRESSION LEVER ADJUSTMENT” section in the CHAPTER 3.

YAMAHA WR250FP - Adjust: - 1

text_image Technical diagram of a mechanical assembly with numbered components, likely illustrating a linkage or coupling mechanism.
  1. Fasten the decompression cable ① and clutch cable ② with a clamp ③.

YAMAHA WR250FP - Adjust: - 2

text_image Technical diagram of a mechanical assembly with labeled parts, showing pipe connection and component positioning
  1. Insert the end of the fuel breather hose ① into the hole of the steering stem.

11. Monter:

Extent of removal:
① Lower bracket removal
② Bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalSTEERING REMOVALHold the machine by placing the suitable stand under the engine.HeadlightHandlebarCable guideFront fender⚠ WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “HANDLEBAR” section.
YAMAHA WR250FP - Monter: - 11Trip meter1Refer to “FRONT FORK” section.Use special tool.Refer to “REMOVAL POINTS”.
2Steering stem nut1
3Front fork2
4Upper bracket1
5Steering ring nut1
6Lower bracket1
7Ball race cover1

DIRECTION

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②

EC563000

REMOVAL POINTS

Steering ring nut

  1. Remove:

- Steering ring nut ①

Use the steering nut wrench ②.

YAMAHA WR250FP - Steering ring nut - 1

Steering nut wrench: YU-33975/90890-01403

YAMAHA WR250FP - Steering ring nut - 2

WARNING

Support the steering stem so that it may not fall down.

YAMAHA WR250FP - WARNING - 1

text_image Technical diagram showing two hands using a hammer to adjust a mechanical component, labeled with parts ① and ②.

Lower bearing

  1. Remove:

- Lower bearing ①

Use the floor chisel ②.

CAUTION:

Take care not to damage the steering stem thread.

YAMAHA WR250FP - CAUTION: - 1

text_image ① ② 12460503

EC563400

Ball race

  1. Remove:

- Ball race ①

Remove the ball race using long rod ② and the hammer.

YAMAHA WR250FP - Ball race - 1

text_image Technical diagram of a mechanical component with labeled part 1

EC564000

INSPECTION

Steering stem

  1. Inspect:

- Steering stem ①

Bend/damage → Replace.

POINTS DE DEPOSE

Hakenschlüssel YU-33975/ 90890-01403

WARNING

natural_image Illustration of a hand turning a ball into a mechanical component with an arrow indicating rotation (no text or symbols)

EC564101

Bearing and ball race

  1. Wash the bearings and ball races with a solvent.
  2. Inspect:

  3. Bearing ①

  4. Ball race

Pitting/damage → Replace bearings and ball races as a set.

Install the bearing in the ball races. Spin the bearings by hand. If the bearings hang up or are not smooth in their operation in the ball races, replace bearings and ball races as a set.

YAMAHA WR250FP - Bearing and ball race - 1

text_image Technical diagram of a mechanical assembly with labeled component 1

EC565000

ASSEMBLY AND INSTALLATION

Lower bracket

  1. Install:

- Lower bearing ①

NOTE:

Apply the lithium soap base grease on the dust seal lip and bearing inner circumference.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing a hand holding a mechanical component with labeled parts ① and ②, and part B indicated.
  1. Install:

  2. Ball race

  3. Upper bearing ①
  4. Ball race cover ②

NOTE:

Apply the lithium soap base grease on the bearing and ball race cover lip.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing mechanical assembly with labeled parts and a magnified inset of a component labeled 'a'
  1. Install:

- Lower bracket ①

NOTE:

Apply the lithium soap base grease on the bearing and the portion ⓐ of the steering stem.

text_image Technical diagram of a mechanical assembly with numbered components labeled 1, 2, and 3.

YAMAHA WR250FP - NOTE: - 1

natural_image Line drawing of hands using a tool to adjust or install a mechanical component (no text or symbols present)

YAMAHA WR250FP - NOTE: - 2

natural_image Line drawing of a hand adjusting a mechanical component with a threaded bolt (no text or symbols)

YAMAHA WR250FP - NOTE: - 3

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②

YAMAHA WR250FP - NOTE: - 4

text_image Technical diagram showing hands assembling a mechanical component with numbered parts labeled ① and ②

4. Install:

  • Washer ①
  • Steering ring nut ②

YAMAHA WR250FP - Install: - 1

7 Nm (0.7 m · kg, 5.1 ft · lb)

Tighten the steering ring nut using the steering nut wrench ③.

Refer to "STEERING HEAD INSPECTION AND ADJUSTMENT" section in the CHAPTER 3.

  1. Check the steering stem by turning it lock to lock. If there is any binding, remove the steering stem assembly and inspect the steering bearings.

6. Install:

- Washer ①

7. Install:

  • Front fork ①
  • Upper bracket ②

NOTE:

  • Temporarily tighten the pinch bolts (lower bracket).
  • Do not tighten the pinch bolts (upper bracket) yet.

8. Install:

  • Washer ①
  • Steering stem nut ②

YAMAHA WR250FP - Install: - 1

  1. After tightening the nut, check the steering for smooth movement. If not, adjust the steering by loosening the steering ring nut little by little.

  2. Adjust:

- Front fork top end ⓐ

YAMAHA WR250FP - Install: - 2

Front fork top end (standard) ⓐ: 5 mm (0.20 in)

* 8mm (0.31 in)

** 10.5 mm (0.41 in)

* For EUROPE

** For AUS, NZ and ZA

YAMAHA WR250FP - Install: - 3

text_image Technical diagram of a mechanical device with numbered components labeled ① and ②
  1. Tighten:

- Pinch bolt (upper bracket) ①

23 Nm (2.3 m · kg, 17 ft · lb)

- Pinch bolt (lower bracket) ②

Tighten the lower bracket to specified torque. If torqued too much, it may cause the front fork to malfunction.

YAMAHA WR250FP - Install: - 4

text_image Technical diagram of a mechanical assembly with labeled component ①
  1. Install:

- Trip meter ①

Extent of removal:
① Swingarm removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalSWINGARM REMOVALHold the machine by placing the suitable stand under the engine.Brake hose holderRear brake caliperBolt (brake pedal)Drive chainWARNINGSupport the machine securely so there is no danger of it falling over.Refer to “FRONT BRAKE AND REAR BRAKE” section.Shift the brake pedal backward.
1Drive chain case1Hold the swingarm.
2Lower chain tensioner1
3Bolt (rear shock absorber-relay arm)1
4Bolt (connecting rod)1
5Pivot shaft1
6Swingarm1

BRAS OSCILLANT

Extent of removal:
① Swingarm disassembly
② Connecting rod removal and disassembly
③ Relay arm removal and disassembly

Extent of removalOrderPart nameQ'tyRemarks
SWINGARM DISASSEMBLY
1Cap2
2Relay arm1
3Connecting rod1
4Collar2
5Oil seal2
6Thrust bearing2
7Bushing2
8Oil seal8
9Bearing8Refer to “REMOVAL POINTS”.

DEMONTAGE DU BRAS OSCILLANT

text_image Technical diagram showing mechanical assembly with labeled parts and directional arrow

YAMAHA WR250FP - DEMONTAGE DU BRAS OSCILLANT - 1

text_image Technical diagram showing a hand fastening a car seatbelt with labeled parts ①, ②, and ③.

EC573000

REMOVAL POINTS

EC573200

Bearing

  1. Remove:

- Bearing ①

NOTE:

Remove the bearing by pressing its outer race.

INSPECTION

Wash the bearings, bushings, collars, and covers in a solvent.

Swingarm

  1. Inspect:

  2. Bearing ①

  3. Bushing ②

Free play exists/unsmooth revolution/rust → Replace bearing and bushing as a set.

  1. Inspect:

- Oil seal ③

Damage → Replace.

YAMAHA WR250FP - Swingarm - 1

text_image Technical diagram showing a hand holding a mechanical component with numbered parts labeled 1, 2, and 3.

YAMAHA WR250FP - Swingarm - 2

text_image Diagram showing a hand holding a scroll with three labeled parts (①, ②, ③) indicating different positions or movements.

EC574210

Relay arm

  1. Inspect:

  2. Bearing ①

  3. Collar ②

Free play exists/unsmooth revolution/rust → Replace bearing and collar as a set.

  1. Inspect:

- Oil seal ③

Damage → Replace.

EC574310

Connecting rod

  1. Inspect:

  2. Bearing ①

  3. Collar ②

Free play exists/unsmooth revolution/rust → Replace bearing and collar as a set.

  1. Inspect:

- Oil seal ③

Damage → Replace.

POINTS DE DEPOSE

Roulement

  1. Déposer:

- Roulement ①

N.B.:

text_image Technical diagram showing a mechanical assembly with labeled components and directional arrow

YAMAHA WR250FP - Roulement - 1

text_image ① ② ① ② a b b a

YAMAHA WR250FP - Roulement - 2

text_image ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① ② ① #a #a

YAMAHA WR250FP - Roulement - 3

text_image ① ② ② a a

EC575000

ASSEMBLY AND INSTALLATION

EC575201

Bearing and oil seal

  1. Install:

  2. Bearing ①

  3. Oil seal ②

To swingarm.

NOTE:

  • Apply the molybdenum disulfide grease on the bearing when installing.
  • Install the bearing by pressing it on the side having the manufacture's marks or numbers.
  • First install the outer and then the inner bearings to a specified depth from inside.

YAMAHA WR250FP - NOTE: - 1

Installed depth of bearings: Outer ⓐ: Zero mm (Zero in) Inner Ⓐ: 8.5 mm (0.33 in)

  1. Install:

  2. Bearing ①

  3. Oil seal ②

To relay arm.

NOTE:

  • Apply the molybdenum disulfide grease on the bearing when installing.
  • Install the bearing by pressing it on the side having the manufacture's marks or numbers.

YAMAHA WR250FP - NOTE: - 1

Installed depth of bearings ⓐ: 5 mm (0.20 in)

  1. Install:

  2. Bearing ①

  3. Oil seal ②

To connecting rod.

NOTE:

  • Apply the molybdenum disulfide grease on the bearing when installing.
  • Install the bearing by pressing it on the side having the manufacture's marks or numbers.

YAMAHA WR250FP - NOTE: - 1

Installed depth of bearings ⓐ: 5 mm (0.20 in)

REMONTAGE ET MONTAGE

text_image Technical diagram showing mechanical assembly with numbered components and labeled parts

YAMAHA WR250FP - REMONTAGE ET MONTAGE - 1

text_image Technical diagram of a mechanical assembly with labeled components and directional arrows indicating motion or assembly.

YAMAHA WR250FP - REMONTAGE ET MONTAGE - 2

text_image Technical diagram showing a mechanical assembly with labeled parts ① and ②, including a valve labeled M.

YAMAHA WR250FP - REMONTAGE ET MONTAGE - 3

text_image Technical diagram of a mechanical assembly with numbered parts and a labeled component M

Swingarm

1. Install:

  • Bushing ①
  • Thrust bearing ②
  • Oil seal ③
  • Collar ④
    To swingarm ⑤.

NOTE:

Apply the molybdenum disulfide grease on the bushings, thrust bearings and oil seal lips.

2. Install:

  • Collar ①
    To relay arm ②.

NOTE:

Apply the molybdenum disulfide grease on the collars, bearings and oil seal lips.

3. Install:

  • Collar ①
    To connecting rod ②.

NOTE:

Apply the molybdenum disulfide grease on the collar, bearings and oil seal lips.

4. Install:

  • Connecting rod ①
  • Bolt (connecting rod) ②
  • Washer ③
  • Nut (connecting rod) ④

80 Nm (8.0 m · kg, 58 ft · lb)

To relay arm ⑤.

NOTE:

Apply the molybdenum disulfide grease on the bolt.

Bras oscillant

1. Monter:

text_image Technical diagram of a mechanical assembly with numbered parts and labeled parts (M, 1, 2, 3, 4)

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram of a mechanical assembly with numbered components and a labeled component M

YAMAHA WR250FP - Monter: - 2

text_image Technical diagram showing mechanical assembly with labeled parts (a) and (b), including directional arrows indicating motion or movement.

YAMAHA WR250FP - Monter: - 3

text_image Technical diagram of a mechanical assembly with numbered components and labeled parts

YAMAHA WR250FP - Monter: - 4

text_image Technical diagram of a mechanical assembly with labeled parts and a directional arrow indicating movement or force.

5. Install:

  • Relay arm ①
  • Bolt (relay arm) ②
  • Washer ③
  • Nut (relay arm) ④ To swingarm.

NOTE:

  • Apply the molybdenum disulfide grease on the bolt.
  • Do not tighten the nut yet.

6. Install:

  • Swingarm ①
  • Pivot shaft ②

YAMAHA WR250FP - Install: - 1

85 Nm (8.5 m · kg, 61 ft · lb)

NOTE:

  • Apply the molybdenum disulfide grease on the pivot shaft.
  • Insert the pivot shaft from right side.

7. Check:

  • Swingarm side play ⓐ Free play exists → Replace thrust bearing.
  • Swingarm up and down movement ⑥ Unsmooth movement/binding/rough spots → Grease or replace bearings, bushings and collars.

8. Install:

  • Bolt (connecting rod) ①
  • Washer ②
  • Nut (connecting rod) ③

NOTE:

  • Apply the molybdenum disulfide grease on the bolt.
  • Do not tighten the nut yet.

9. Install:

  • Bolt (rear shock absorber-relay arm) ①
  • Nut (rear shock absorber-relay arm) ②

YAMAHA WR250FP - Install: - 1

53 Nm (5.3 m · kg, 38 ft · lb)

NOTE:

Apply the molybdenum disulfide grease on the bolt.

5. Monter:

  • Bras de relais ①
  • Boulon (bras relais) ②
  • Rondelle ③
  • Ecrou (bras relais) ④ Sur le bras oscillant.

N.B.:

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

YAMAHA WR250FP - N.B.: - 1

text_image Technical diagram showing mechanical assembly with labeled component ①

YAMAHA WR250FP - N.B.: - 2

text_image ① ① a -

YAMAHA WR250FP - N.B.: - 3

text_image Technical diagram of a car suspension system with numbered components and wiring connections

YAMAHA WR250FP - N.B.: - 4

text_image Technical diagram of a mechanical assembly with numbered parts for identification

10. Tighten:

- Nut (connecting rod) ①

YAMAHA WR250FP - Tighten: - 1

80 Nm (8.0 m · kg, 58 ft · lb)

11. Tighten:

- Nut (relay arm) ①

YAMAHA WR250FP - Tighten: - 1

80 Nm (8.0 m · kg, 58 ft · lb)

12. Install:

- Cap ①

NOTE: Install the right cap with its mark ⓐ facing forward.

13. Install:

  • Bolt (lower chain tensioner) ①
  • Washer ②
  • Collar ③
  • Lower chain tensioner ④
  • Nut (lower chain tensioner) ⑤

YAMAHA WR250FP - Install: - 1

  • Drive chain case ①
  • Drive chain case cover ②
  • Bolt {drive chain case [ = 50 mm (1.97 in)]} ③
  • Nut (drive chain case) ④

YAMAHA WR250FP - Install: - 2

7 Nm (0.7 m · kg, 5.1 ft · lb)

- Bolt {drive chain case cover [ ℓ = 10 mm (0.39 in)]} ⑤

YAMAHA WR250FP - Install: - 3

7 Nm (0.7 m · kg, 5.1 ft · lb)

10. Serrer:

- Ecrou (bielle) ①

80 Nm (8,0 m · kg, 58 ft · lb)

10. Festziehen:

Extent of removal:
① Rear shock absorber removal
② Rear shock absorber disassembly

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalREAR SHOCK ABSORBER REMOVALHold the machine by placing the suitable stand under the engine.Seat and side coversSilencerDrain the coolant.Coolant reservoir⚠ WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4.Refer to “EXHAUST PIPE AND SILENCER” section in the CHAPTER 4.Refer to “COOLANT REPLACEMENT” section in the CHAPTER 3.Refer to “RADIATOR” section in the CHAPTER 4.
121Taillight connector2
2Band2
3Bolt (reservoir tank)1
4Clamp (air filter joint)1Only loosening.
5Rear frame1
6Bolt (rear shock absorber-relay arm)1Hold the swingarm.
7Bolt (rear shock absorber-frame)1
8Rear shock absorber1

AMORTISSEUR ARRIERE

This rear shock absorber is provided with a separate type tank filled with high-pressure nitrogen gas. To prevent the danger of explosion, read and understand the following information before handling the shock absorber.

The manufacturer can not be held responsible for property damage or personal injury that may result from improper handling.

  1. Never tamper or attempt to disassemble the cylinder or the tank.
  2. Never throw the rear shock absorber into an open flame or other high heat. The rear shock absorber may explode as a result of nitrogen gas expansion and/or damage to the hose.
  3. Be careful not to damage any part of the gas tank. A damaged gas tank will impair the damping performance or cause a malfunction.
  4. Take care not to scratch the contact surface of the piston rod with the cylinder; or oil could leak out.
  5. Never attempt to remove the plug at the bottom of the nitrogen gas tank. It is very dangerous to remove the plug.
  6. When scrapping the rear shock absorber, follow the instructions on disposal.

YAMAHA WR250FP - AMORTISSEUR ARRIERE - 1

natural_image Technical line drawing of a mechanical assembly with coiled spring and housing (no text or symbols)

NOTES ON DISPOSAL (YAMAHA DEALERS ONLY)

Before disposing the rear shock absorber, be sure to extract the nitrogen gas from valve ①. Wear eye protection to prevent eye damage from escaping gas and/or metal chips.

WARNING

To dispose of a damaged or worn-out rear shock absorber, take the unit to your Yamaha dealer for this disposal procedure.

REMARQUES CONCERNANT LA MANIPULATION

! AVERTISSEMENT

text_image Technical diagram of a mechanical assembly with labeled component ① and directional arrow indicating motion

YAMAHA WR250FP - ! AVERTISSEMENT - 1

text_image Technical diagram of a mechanical assembly with labeled component ① and directional arrow indicating motion

YAMAHA WR250FP - ! AVERTISSEMENT - 2

text_image Technical diagram of a mechanical device with labeled component ① and directional arrow indicating flow or movement.

YAMAHA WR250FP - ! AVERTISSEMENT - 3

text_image ① ② ③ ④ I2340401

YAMAHA WR250FP - ! AVERTISSEMENT - 4

text_image Diagram showing two mechanical or fluid circulation patterns with labeled components and directional arrows indicating flow or movement.

EC583000

REMOVAL POINTS

EC583320

Bearing

  1. Remove:

- Stopper ring (upper bearing) ①

NOTE: ____

Press in the bearing while pressing its outer race and remove the stopper ring.

  1. Remove:

- Upper bearing ①

NOTE: ____

Remove the bearing by pressing its outer race.

  1. Remove:

- Lower bearing ①

NOTE: ____

Remove the bearing by pressing its outer race.

EC584000

INSPECTION

Rear shock absorber

  1. Inspect:

  2. Damper rod ① Bends/damage → Replace rear shock absorber assembly.

  3. Shock absorber ② Oil leaks → Replace rear shock absorber assembly. Gas leaks → Replace rear shock absorber assembly.
  4. Spring ③ Damage → Replace spring. Fatigue → Replace spring. Move spring up and down.
  5. Spring guide ④ Wear/damage → Replace spring guide.
  6. Bearing ⑤ Free play exists/unsmooth revolution/rust → Replace.

POINTS DE DEPOSE

Roulement

  1. Déposer:
text_image Technical diagram of a mechanical assembly with labeled component ①

EC585000

ASSEMBLY AND INSTALLATION

EC585300

Bearing

  1. Install:

- Upper bearing ①

NOTE: ____ Install the bearing parallel until the stopper ring groove appears by pressing its outer race.

CAUTION:

Do not apply the grease on the bearing outer race because it will wear the rear shock absorber surface on which the bearing is press fitted.

YAMAHA WR250FP - CAUTION: - 1

text_image ① New
  1. Install:

- Stopper ring (upper bearing) ①

New

NOTE: After installing the stopper ring, push back the bearing until it contacts the stopper ring.

YAMAHA WR250FP - CAUTION: - 2

text_image Technical diagram of a mechanical device with labeled components and directional arrows, including parts marked ① and ②.
  1. Install:

- Lower bearing ①

NOTE: ____ Install the bearing by pressing it on the side having the manufacture's marks or numbers.

YAMAHA WR250FP - CAUTION: - 3

text_image Technical diagram showing a hand holding a coiled spring with numbered parts labeled ①, ②, and ③.

YAMAHA WR250FP - CAUTION: - 4

Installed depth of the bearing ⓐ: 4 mm (0.16 in)

Spring (rear shock absorber)

  1. Install:

  2. Spring ①
    • Upper spring guide ②

  3. Lower spring guide ③

REMONTAGE ET MONTAGE Roulement

1. Monter:

natural_image Technical line drawing of a mechanical spring assembly with labeled component (1), no readable text or symbols beyond label

YAMAHA WR250FP - Monter: - 1

text_image a 12340602

YAMAHA WR250FP - Monter: - 2

natural_image Technical illustration of a mechanical suspension component with threaded end and labeled part (1), no readable text or symbols beyond the label.

YAMAHA WR250FP - Monter: - 3

flowchart
graph TD
    A["1"] --> B["2"]
    B --> C["3"]
    C --> D["4"]
    D --> E["5"]
    E --> F["6"]
    F --> G["7"]
    G --> H["8"]
    H --> I["9"]
    I --> J["10"]
    J --> K["11"]
    K --> L["12"]
    L --> M["13"]
    M --> N["14"]
    N --> O["15"]
    O --> P["16"]
    P --> Q["17"]
    Q --> R["18"]
    R --> S["19"]
    S --> T["20"]
    T --> U["21"]
    U --> V["22"]
    V --> W["23"]
    W --> X["24"]
    X --> Y["25"]
    Y --> Z["26"]

2. Tighten:

- Adjuster ①

3. Adjust:

- Spring length (installed) ⓐ

Spring length (installed) a:
Standard lengthExtent of adjustment
244 mm (9.61 in)* 247 mm (9.72 in)** 243.5 mm (9.59 in)240.5 ~ 258.5 mm(9.47 ~ 10.18 in)

* For EUROPE
** For AUS, NZ and ZA

NOTE:

The length of the spring (installed) changes 1.5 mm (0.06 in) per turn of the adjuster.

CAUTION:

Never attempt to turn the adjuster beyond the maximum or minimum setting.

4. Tighten:

- Locknut ①

Rear shock absorber

1. Install:

  • Dust seal ①
  • O-ring ②
  • Collar ③

YAMAHA WR250FP - Install: - 1

NOTE:

  • Apply the molybdenum disulfide grease on the bearing.
  • Apply the lithium soap base grease on the dust seals, O-rings and collars.

2. Serrer:

text_image Technical diagram of a mechanical assembly with labeled parts ① and ②, showing components like a valve and housing.

YAMAHA WR250FP - Serrer: - 1

text_image Technical diagram showing mechanical assembly with labeled parts and a valve indicator

YAMAHA WR250FP - Serrer: - 2

text_image Technical diagram showing mechanical assembly with numbered components and labeled parts

YAMAHA WR250FP - Serrer: - 3

text_image Technical diagram of a mechanical assembly with numbered component annotations

2. Install:

  • Bushing ①
  • Collar ②
  • Dust seal ③

NOTE:

  • Apply the molybdenum disulfide grease on the bearing.
  • Apply the lithium soap base grease on the bushing, collars and dust seals.
  • Install the dust seals with their lips facing outward.

3. Install:

- Rear shock absorber

4. Install:

  • Bolt (rear shock absorber-frame) ①
  • Nut (rear shock absorber-frame) ②

56 Nm (5.6 m · kg, 40 ft · lb)

NOTE:

Apply the molybdenum disulfide grease on the bolt.

5. Install:

  • Bolt (rear shock absorber-relay arm) ①
  • Nut (rear shock absorber-relay arm) ②

53 Nm (5.3 m · kg, 38 ft · lb)

NOTE:

Apply the molybdenum disulfide grease on the bolt.

6. Install:

  • Rear frame ①
  • Bolt (rear frame) ②

29 Nm (2.9 m · kg, 21 ft · lb)

- Bolt (reservoir tank) ③

10 Nm (1.0 m · kg, 7.2 ft · lb)

7. Tighten:

- Screw (air filter joint) ①

3 Nm (0.3 m · kg, 2.2 ft · lb)

2. Monter:

  • Douille ①
  • Collerette ②
  • Joint antipoussière ③

N.B.:

text_image Technical diagram of a mechanical assembly with numbered components, likely for assembly or maintenance instructions.
  1. Install:

  2. Band ①

  3. Taillight connector ②

8. Monter:

① Headlight
② Voltage regulator
③ Engine stop switch
④ Throttle position sensor
⑤ Taillight
⑥ Neutral switch
⑦ CDI magneto
⑧ Spark plug
⑨ Ignition coil
⑩ Light switch
⑪ CDI unit

COLOR CODE

BBlack
BrBrown
GGreen
GyGray
LBlue
OOrange
PPink
RRed
SbSky blue

W ...... White
Y ....Yellow
B/L ......Black/Blue
B/W ....Black/White
B/Y ...... Black/Yellow
G/B....Green/Black
L/W ......Blue/White
R/W......Red/White

YAMAHA WR250FP - Monter: - 1

text_image Technical diagram of a motorcycle with numbered components for identification

YAMAHA WR250FP - Monter: - 2

text_image Technical diagram of a motorcycle's internal components with numbered parts for identification

EC612000

WIRING DIAGRAM

YAMAHA WR250FP - WIRING DIAGRAM - 1

flowchart
graph TD
    subgraph Component_1
        A["①"] --> B["L"]
        B --> C["B"]
        C --> D["Y"]
        D --> E["L"]
        E --> F["B"]
        F --> G["Y"]
        G --> H["L"]
        H --> I["B"]
        I --> J["Y"]
        J --> K["L"]
        K --> L["B"]
        L --> M["L"]
        M --> N["B"]
        N --> O["②"]
        P["⑩"] --> Q["⑪"]
        Q --> R["BW"]
        R --> S["G/B"]
        S --> T["B"]
        T --> U["BW"]
        U --> V["③"]
        W["⑦"] --> X["Br"]
        X --> Y["P"]
        Y --> Z["G"]
        Z --> AA["R"]
        AA --> AB["W"]
        AB --> AC["B"]
        AC --> AD["⑨"]
        AE["⑥"] --> AF["Sb"]
        AF --> AG["L/W"]
        AG --> AH["Sb"]
        AH --> AI["L/W"]
        AI --> AJ["Sb"]
        AJ --> AK["W"]
        AK --> AL["⑥"]
        AM["④"] --> AN["⑤"]
        AN --> AO["L"]
        AO --> AP["Y"]
        AP --> AQ["L"]
        AQ --> AR["Y"]
        AR --> AS["B"]
        AS --> AT["B/L"]
        AT --> AU["By"]
        AU --> AV["Gy"]
        AV --> AW["B"]
        AW --> AX["Gy"]

PARTIE

ELECTRIQUE

COMPOSANTS ELECTRI- QUES ET SCHEMA DE CABLAGE

COMPOSANTS ELECTRIQUES

A map-controlled, CDI ignition system is used in the WR250F.

The microcomputer in the CDI unit detects the engine speed and throttle position, thus determining the optimum ignition timing through the entire operating range. In this way, quick throttle response can be achieved according to various riding conditions.

YAMAHA WR250FP - COMPOSANTS ELECTRIQUES - 1

text_image Throttle position sensor CDI unit Ignition coil Pickup coil CDI magneto rotor

■ Function of Component

ComponentFunction
Throttle position sensorDetects throttle valve opening and inputs it into the computer in the CDI unit as a throttle opening signal.
Pickup coilDetects signal rotor revolutions and inputs them into the computer in the CDI unit as engine revolution signals.
CDI unitThe signals of the throttle position sensor and pickup coil sensor are analyzed by the computer in the CDI unit, which then adjusts ignition timing for the operation requirements.

■ Principal of 3-Dimensional Control

Conventionally, ignition timing was controlled only by engine revolutions (2-dimensional control). However, ignition timing needs advancement also by engine load. Thus, accurate ignition timing can be determined by adding throttle opening to determine ignition timing (3-dimensional control).

YAMAHA WR250FP - ■ Principal of 3-Dimensional Control - 1

text_image Ignition timing Throttle opening Revolutions

3-D Image Map of Ignition Timing different from actual characteristics)

BLOC CDI CONTROLE PAR MICROPROCESSEUR

Use the following steps for checking the possibility of the malfunctioning engine being attributable to ignition system failure and for checking the spark plug which will not spark.

YAMAHA WR250FP - BLOC CDI CONTROLE PAR MICROPROCESSEUR - 1

flowchart
graph TD
    A["Spark gap test"] -->|No spark| B["Check entire ignition system for connection."]
    B -->|OK| C["Check engine stop switch."]
    C -->|OK| D["Check ignition coil."]
    D -->|OK| E["Check CDI magneto."]
    E -->|OK| F["Check neutral switch."]
    F -->|OK| G["Replace CDI unit."]

    H["*Clean or replace spark plug."] --> I["No good"]
    I --> J["Repair or replace."]
    J --> K["No good"]
    K --> L["Replace."]

    M["Primary coil"] -->|No good| N["Replace."]
    O["Secondary coil"] -->|No good| P["Replace."]

    Q["Pickup coil"] -->|No good| R["Replace."]
    S["Charging coil"] -->|No good| T["Replace."]

    U["Repair or replace."] --> V["No good"]
    V --> W["Replace."]

    X["No good"] --> Y["Repair or replace."]

*marked: Only when the ignition checker is used.

NOTE:

  • Remove the following parts before inspection.
    1) Seat
    2) Fuel tank
  • Use the following special tools in this inspection.

YAMAHA WR250FP - NOTE: - 1

Dynamic spark tester: YM-34487

Ignition checker: 90890-06754

YAMAHA WR250FP - NOTE: - 2

Pocket tester: YU-3112-C/90890-03112

SYSTEME D'ALLUMAGE

ETAPES DU CONTROLE

text_image Technical diagram of a mechanical assembly with numbered components, likely for repair or maintenance instructions.

SPARK GAP TEST

  1. Disconnect the spark plug cap from spark plug.
  2. Connect the dynamic spark tester ① (ignition checker ②) as shown.
  3. Spark plug cap ③
  4. Spark plug ④

A For USA and CDN
B Except for USA and CDN

  1. Kick the kickstarter crank.
  2. Check the ignition spark gap.
  3. Start engine, and increase spark gap until misfire occurs. (for USA and CDN only)
Minimum spark gap: 6.0 mm (0.24 in)

EC624000 COUPLERS AND LEADS CONNECTION INSPECTION

1. Check:

- Couplers and leads connection Rust/dust/looseness/short-circuit → Repair or replace.

YAMAHA WR250FP - Check: - 1

text_image Technical diagram showing a mechanical assembly with labeled parts and an inset showing a component labeled B/B/W.

ENGINE STOP SWITCH INSPECTION

1. Inspect:

- Engine stop switch conduct

Tester (+) lead → Black/White lead 1
Tester (−) lead → Black lead 2
B/W1B2Tester selec-tor position
PUSH IN○—Ω×1
FREE

No continuous while being pushed → Replace. Continuous while being freed → Replace.

TEST DE LA LONGUEUR D'ETIN- CELLE D'ALLUMAGE

text_image Technical diagram showing mechanical assembly with numbered components and labeled parts

EC626002

IGNITION COIL INSPECTION

1. Inspect:

- Primary coil resistance Out of specification → Replace.

Tester (+) lead → Orange lead 1
Tester (−) lead → Black lead 2
Primary coil resistanceTester selector position
0.20 ~ 0.30 Ω at 20 °C (68 °F)Ω × 1

YAMAHA WR250FP - Inspect: - 1

text_image Technical diagram showing mechanical assembly with numbered components and labeled parts

2. Inspect:

- Secondary coil resistance Out of specification → Replace.

Tester (+) lead → Spark plug lead 1
Tester (−) lead → Orange lead 2
Secondary coil resistanceTester selector position
9.5 ~ 14.3 kΩ at 20 °C (68 °F)kΩ × 1

NOTE:

When inspecting the secondary coil resistance, remove the spark plug cap.

YAMAHA WR250FP - NOTE: - 1

text_image Technical diagram showing car component assembly with labeled parts and a numbered inset table for vehicle model selection.

CDI MAGNETO INSPECTION

1. Inspect:

- Pickup coil resistance Out of specification → Replace.

Tester (+) lead → Red lead 1
Tester (−) lead → White lead 2
YAMAHA WR250FP - Inspect: - 1Pickup coil resistanceTester selector position
248 ~ 372 Ω at 20 °C (68 °F)Ω × 100

CONTROLE DE LA BOBINE D'ALLUMAGE

1. Vérifier:

text_image Technical diagram showing a mechanical assembly with labeled components and a corresponding color-coded legend for alphanumeric codes.

YAMAHA WR250FP - Vérifier: - 1

text_image Technical diagram showing car component assembly with labeled parts and a numbered inset table for vehicle model selection.

2. Inspect:

- Charging coil 1 resistance Out of specification → Replace.

Tester (+) lead → Brown lead 1
Tester (−) lead → Green lead 2
YAMAHA WR250FP - Inspect: - 1Charging coil 1 resistanceTester selector position
640 ~ 960 Ω at 20 °C (68 °F)Ω × 100

3. Inspect:

- Charging coil 2 resistance Out of specification → Replace.

Tester (+) lead → Pink lead 1
Tester (−) lead → Green lead 2
Charging coil 2 resistanceTester selector position
464 ~ 696 Ω at 20 °C (68 °F)Ω × 100

YAMAHA WR250FP - Inspect: - 1

text_image Technical diagram of a mechanical assembly with numbered components, likely for assembly or maintenance instructions.

NEUTRAL SWITCH INSPECTION

1. Inspect:

- Neutral switch conduct

Tester (+) lead → Sky blue lead 1
Tester (−) lead → Ground 2
Sb1Ground2Tester selec-tor position
NEUTRALΩ×1
IN GEAR

No continuous while in neutral → Replace.

Continuous while in gear → Replace.

EC628000

CDI UNIT INSPECTION

Check all electrical components. If no fault is found, replace the CDI unit. Then check the electrical components again.

2. Vérifier:

If the throttle position sensor will not operate, use the following inspection steps.

YAMAHA WR250FP - Vérifier: - 1

flowchart
graph TD
    A["Check entire ignition system for connection."] -->|OK| B["Check throttle position sensor."]
    B -->|OK| C["*Check CDI magneto."]
    C -->|OK| D["Check CDI unit."]
    A -->|No good| E["Repair or replace."]
    B --> F["Throttle position sensor coil"]
    C --> G["Charging coil"]
    D --> H["Throttle position sensor input voltage"]
    F -->|No good| I["Replace."]
    G -->|No good| J["Replace."]
    H -->|No good| K["Replace."]

*marked: Refer to “IGNITION SYSTEM” section.

NOTE:

Use the following special tools in this inspection.

YAMAHA WR250FP - NOTE: - 1

Pocket tester:

YU-3112-C/90890-03112

YAMAHA WR250FP - NOTE: - 2

Inductive tachometer:

YU-8036-B

Engine tachometer:

90890-03113

CIRCUIT DU CAPTEUR DE PAPILLON DES GAZ

ETAPES DU CONTROLE

text_image Technical diagram of a mechanical assembly with numbered component labels

HANDLING NOTE

CAUTION:

Do not loosen the screws (throttle position sensor) ① except when changing the throttle position sensor due to failure because it will cause a drop in engine performance.

EC624000

COUPLERS AND LEADS CONNECTION INSPECTION

1. Check:

- Couplers and leads connection Rust/dust/looseness/short-circuit → Repair or replace.

YAMAHA WR250FP - Check: - 1

text_image ① L Y B ② ① ② ②

THROTTLE POSITION SENSOR COIL INSPECTION

1. Inspect:

- Throttle position sensor coil resistance Out of specification → Replace.

Tester (+) lead → Blue lead ① Tester (−) lead → Black lead ②

Throttle position sensor coil resistanceTester selector position
4 ~ 6 kΩ at 20 °C (68 °F)kΩ × 1

YAMAHA WR250FP - Inspect: - 1

natural_image Mechanical assembly diagram showing a valve mechanism with no visible text or symbols

2. Loosen:

- Throttle stop screw ①

NOTE:

Turn out the throttle stop screw until the throttle shaft is in the full close position.

REMARQUE

ATTENTION:

text_image Diagram showing car seatbelt usage with labeled parts and a vehicle compartment diagram for L, Y, B sections

3. Inspect:

  • Throttle position sensor coil variable resistance
    Check that the resistance in increased as the throttle grip is moved from the full close position to the full open position.
    Out of specification → Replace.
Tester (+) lead → Yellow lead 1
Tester (−) lead → Black lead 2
Throttle position sensor coil variable resistanceTester selector position
Full closedFull openedkΩ × 1
Zero ~ 3 kΩ at 20 °C (68 °F)4 ~ 6 kΩ at 20 °C (68 °F)

YAMAHA WR250FP - Inspect: - 1

text_image Technical diagram of a mechanical assembly with numbered components labeled ①, ②, and ③.

THROTTLE POSITION SENSOR REPLACEMENT AND ADJUSTMENT

1. Remove:

  • Throttle position sensor coupler
  • Screw (throttle position sensor) ①
  • Washer ②
  • Throttle position sensor ③

NOTE:

Loosen the screws (throttle position sensor) using the T20 bit (tamper resistant fastener type).

2. Replace:

- Throttle position sensor

3. Install:

  • Throttle position sensor ①
  • Washer ②
  • Screw (throttle position sensor) ③

4. Install:

- Throttle position sensor coupler

YAMAHA WR250FP - Install: - 1

text_image Technical diagram of a mechanical assembly with numbered components and an inset view labeled a and b.

NOTE:

  • Align the slot ⓐ in the throttle position sensor with the projection ⓑ on the carburetor.
  • Temporarily tighten the screws (throttle position sensor).

3. Contrôler:

- Engine idling speed Refer to “ENGINE IDLING SPEED ADJUSTMENT” section in the CHAPTER 3.

YAMAHA WR250FP - Contrôler: - 1

text_image Technical diagram showing a hand holding a tool with numbered parts labeled 1 to 4
  1. Insert the thin electric conductors ② (lead) into the throttle position sensor coupler ①, as shown, and connect the tester to them.

Tester (+) lead → Yellow lead ③ Tester (−) lead → Black lead ④

CAUTION:

  • Do not insert the electric conductors more than required because it may reduce the waterproof function of the coupler.
  • Make sure that a short-circuit does not develop between the terminals because it may cause damage to electrical components.

YAMAHA WR250FP - CAUTION: - 1

text_image Technical diagram showing mechanical assembly with labeled parts and directional arrows indicating motion or force vectors
  1. Start the engine.
  2. Adjust:

- Throttle position sensor output voltage

Adjustment steps:

Adjust the installation angle of the throttle position sensor ① to obtain the specified output voltage.

NOTE:

Measure the output voltage accurately with a digital electronic voltmeter that gives an easy reading of a small voltage.

YAMAHA WR250FP - NOTE: - 1Throttle position sensor output voltageTester selector position
0.58 ~ 0.78 VDCV

5. Ajuster:

text_image Technical diagram of a mechanical assembly with numbered component labels

YAMAHA WR250FP - Ajuster: - 1

text_image ① ② ① Y L B/L ②

9. Tighten:

- Screw (throttle position sensor) ①

NOTE:

Tighten the screws (throttle position sensor) using the T20 bit (tamper resistant fastener type).

  1. Stop the engine.

THROTTLE POSITION SENSOR INPUT VOLTAGE INSPECTION

  1. Disconnect the throttle position sensor coupler.
  2. Start the engine.
  3. Inspect:

- Throttle position sensor input voltage Out of specification → Replace the CDI unit.

Tester (+) lead → Blue lead 1
Tester (−) lead → Black/Blue lead 2
YAMAHA WR250FP - THROTTLE POSITION SENSOR INPUT VOLTAGE INSPECTION - 1

9. Serrer:

Refer to the following flow chart when inspecting the ignition system for possible problems.

YAMAHA WR250FP - Serrer: - 1

flowchart
graph TD
    A["Check the bulb and bulb socket."] -->|OK| B["Check the light switch."]
    B -->|OK| C["Check the CDI magneto."]
    C -->|OK| D["Check the entire lighting system proper for connections."]
    D -->|OK| E["Check the voltage regulator."]
    E --> F["Out-put voltage"]
    F -->|No good| G["Replace."]
    F -->|No good| H["Replace."]
    H --> I["Replace."]
    I --> J["Replace."]
    J --> K["Replace."]
    K --> L["Replace."]
    L --> M["Replace."]
    M --> N["Replace."]
    N --> O["Replace."]
    O --> P["Replace."]
    P --> Q["Replace."]
    Q --> R["Replace."]
    R --> S["Replace."]
    S --> T["Replace."]
    T --> U["Replace."]
    U --> V["Replace."]
    V --> W["Replace."]
    W --> X["Replace."]
    X --> Y["Replace."]
    Y --> Z["Replace."]
    Z --> AA["Replace."]
    AA --> AB["Replace."]
    AB --> AC["Replace."]
    AC --> AD["Replace."]
    AD --> AE["Replace."]
    AE --> AF["Replace."]
    AF --> AG["Replace."]
    AG --> AH["Replace."]
    AH --> AI["Replace."]
    AI --> AJ["Replace."]
    AJ --> AK["Replace."]
    AK --> AL["Replace."]
    AL --> AM["Replace."]
    AM --> AN["Replace."]
    AN --> AO["Replace."]
    AO --> AP["Replace."]
    AP --> AQ["Replace."]
    AQ --> AR["Replace."]
    AR --> AS["Replace."]
    AS --> AT["Replace."]
    AT --> AU["Replace."]
    AU --> AV["Replace."]
    AV --> AW["Replace."]
    AW --> AX["Replace."]
    AX --> AY["Replace."]

NOTE:

  • Replace the bulb and/or bulb socket.
    1) Seat
    2) Fuel tank
  • Use the following special tool.

YAMAHA WR250FP - NOTE: - 1

Pocket tester: YU-3112-C/90890-03112

YAMAHA WR250FP - NOTE: - 2

Inductive tachometer: YU-8036-B

Engine tachometer: 90890-03113

SYSTEME D'ECLAIRAGE

PROCEDURES DE VERIFICATION

text_image Y L B Y L B ① ②

LIGHT SWITCH INSPECTION

1. Inspect:

• Light switch continuity

Tester (+) lead → Yellow lead 1
Tester (−) lead → Blue lead 2
Y1L2Tester selec-tor position
Ω × 1
OFF

No continuous while being ⚙→ Replace.

Continuous while being OFF → Replace.

YAMAHA WR250FP - Inspect: - 1

text_image Diagram showing car seatbelt switch and battery compartment with labeled components and a corresponding electrical component table.

CDI MAGNETO INSPECTION

1. Inspect:

- Lighting coil resistance

Out of specification → Replace.

Tester (+) lead → Yellow lead 1
Tester (−) lead → Black lead 2
Lighting coil resistanceTester selector position
0.16 ~ 0.24 Ω at 20 °C (68 °F)Ω × 1

VOLTAGE REGULATOR INSPECTION

  1. Start the engine.
  2. Turn on the headlight and taillight by turning on the light switch.
  3. Inspect:

- Out-put voltage

Out of specification → Replace voltage regulator.

YAMAHA WR250FP - VOLTAGE REGULATOR INSPECTION - 1

text_image Technical diagram showing labeled components of a vehicle or engine assembly with parts numbered ① and ②, including a component labeled 'L' and part identifier 'B'.
Tester (+) lead → Blue lead 1
Tester (−) lead → Black lead 2
YAMAHA WR250FP - VOLTAGE REGULATOR INSPECTION - 2Out-put voltageTester selector position
13.3 ~ 14.3 V at 5,000 r/minACV-20

VERIFICATION INTERRUPTEUR LUMIERES

  1. Vérifier:
  • The air/fuel mixture will vary depending on atmospheric conditions. Therefore, it is necessary to take into consideration the air pressure, ambient temperature, humidity, etc., when adjusting the carburetor.
  • Perform a test run to check for proper engine performance (e.g., throttle response) and spark plug(-s) discoloration or fouling. Use these readings to determine the best possible carburetor setting.

NOTE:

It is recommended to keep a record of all carburetor settings and external conditions (e.g., atmospheric conditions, track/surface conditions, lap times) to make future carburetor setting easier.

YAMAHA WR250FP - NOTE: - 1

WARNING

  • The carburetor is a part of the fuel line. Therefore, be sure to install it in a well-ventilated area, away from flammable objects and any sources of fire.
  • Never look into the carburetor intake. Flames may shoot out from the pipe if the engine backfires while it is being started. Gasoline may be discharged from the accelerator pump nozzle when the carburetor has been removed.

MISES AU POINT MOTEUR

  • The carburetor is extremely sensitive to foreign matter (dirt, sand, water, etc.). During installation, do not allow foreign matter to get into the carburetor.
  • Always handle the carburetor and its components carefully. Even slight scratches, bends or damage to carburetor parts may prevent the carburetor from functioning correctly. Carefully perform all servicing with the appropriate tools and without applying excessive force.
  • When the engine is stopped or when riding at no load, do not open and close the throttle unnecessarily. Otherwise, too much fuel may be discharged, starting may become difficult or the engine may not run well.
  • After installing the carburetor, check that the throttle operates correctly and opens and closes smoothly.

Atmospheric conditions and carburetor settings

Air temp.HumidityAir pressure (altitude)MixtureSetting
HighHighLow (high)RicherLeaner
LowLowHigh (low)LeanerRicher

The air density (i.e., concentration of oxygen in the air) determines the richness or leanness of the air/fuel mixture. Therefore, refer to the above table for mixture settings.

That is:

  • Higher temperature expands the air with its resultant reduced density.
  • Higher humidity reduces the amount of oxygen in the air by so much of the water vapor in the same air.
  • Lower atmospheric pressure (at a high altitude) reduces the density of the air.

ATTENTION:

Effects of the setting parts on the throttle valve opening
YAMAHA WR250FP - ATTENTION: - 1

text_image ① ② ③ ④ A 1/8 1/4 1/2 3/4 B

A Closed
B Fully open
① Pilot screw/pilot jet
② Throttle valve cutaway
③ Jet needle
④ Main jet

Main system

The FLATCR carburetor has a primary main jet. This type of main jet is perfect for racing motorcycles since it supplies an even flow of fuel, even at full load. The main air jet has almost no effect on the air-fuel mixture. Use the main jet and the jet needle to set the carburetor.

Pilot system

The FLATCR carburetor is manufactured with a pilot screw. The pilot screw adjustment ranges from fully closed throttle to 1/4 open throttle.

text_image Technical schematic diagram of a mechanical device with numbered components for identification

YAMAHA WR250FP - Pilot system - 1

text_image Technical diagram of a mechanical assembly with labeled component ①

① Jet needle
② Main air jet
③ Pilot air jet
④ Needle jet
⑤ Main jet
⑥ Pilot jet
⑦ Pilot screw

Main jet adjustment

The richness of the air-fuel mixture at full throttle can be set by changing the main jet ①.

Standard main jet#175* #172** #170

* For EUROPE
** For CDN, ZA, AUS and NZ

If the air-fuel mixture is too rich or too lean, the engine power will drop, resulting in poor acceleration.

Effects of changing the main jet (reference)
YAMAHA WR250FP - Main jet adjustment - 1

line | Time | Series 1 | Series 2 | | :--- | :--- | :--- | | 1/4 | +10% | - | | 1/2 | +10% | - | | 3/4 | +10% | - | | B | -10% | +175 |

A Idle
B Fully open

natural_image Technical line drawing of a mechanical assembly with no visible text or symbols

Pilot screw adjustment

The richness of the air-fuel mixture with the throttle fully closed to 1/4 open can be set by turning the pilot screw ①. Turning in the pilot screw will make the mixture lean at low speeds, and turning it out will enrich it.

Standard pilot screw position2* 1** 1-1/8(example)

* For EUROPE
** For CDN, ZA, AUS and NZ

NOTE:

  • If the engine idling speed fluctuates, turn the pilot screw only 1/2 of a turn in either direction.
  • To optimize the fuel flow at a smaller throttle opening, each machine's pilot screw has been individually set at the factory. Before adjusting the pilot screw, turn it in fully and count the number of turns. Record this number as the factory-set number of turns out.

Effects of adjusting the pilot screw (reference)
YAMAHA WR250FP - NOTE: - 1

line | Position | Value | |---|---| | A | 1/4 | | 1/2 | 1/2 | | 3/4 | 3/4 | | B | +5% | | ③ | -5% | | ① | ① | | ② | ② |

A Idle
B Fully open
① 2-1/2 turns out
② 1-1/2 turns out
③ 2 turns out

YAMAHA WR250FP - NOTE: - 2

text_image Technical diagram of a mechanical device with numbered components and labeled parts

Pilot jet adjustment

The richness of the air-fuel mixture with the throttle open 1/4 or less can be set by adjusting the pilot jet ①.

Standard pilot jet#40
bar | Section | Value | | :--- | :--- | | A | 1/4 | | 1/4 | 1/2 | | 1/2 | 3/4 | | 3/4 | +5% | | 3/4 | -5% |
line | Point | Value | |---|---| | ① | 1/4 | | ② | 1/2 | | +5% | 3/4 | | -5% | 3/4 |

A Leerlauf

B Vollgas

line | Position | Value | |---|---| | A | 1/4 | | 1/2 | 1/2 | | 3/4 | 3/4 | | B | +5% | | ③ | -5% |

Effects of adjusting the pilot jet (reference)
YAMAHA WR250FP - Pilot jet adjustment - 1
A Idle
B Fully open

YAMAHA WR250FP - Pilot jet adjustment - 2

text_image 1 2 3 4 5 6 7 ①

Jet needle groove position adjustment

Adjusting the jet needle ① position affects the acceleration when the throttle is 1/8 to 3/4 open.

  1. Too rich at intermediate speeds
    Rough engine operation is felt and the engine will not pick up speed smoothly. In this case, step up the jet needle clip by one groove and move down the needle to lean out the mixture.
  2. Too lean at intermediate speeds
    The engine breathes hard and will not pick up speed quickly.
    Step down the jet needle clip by one groove and move up the needle to enrich the mixture.
Standard clip positionNo.3 groove* No. 4 groove

* For EUROPE

Effects of changing the jet needle groove position (reference)
YAMAHA WR250FP - Jet needle groove position adjustment - 1

line | Time | Value | |------|-------| | 1/4 | 1 | | 1/2 | 0 | | 3/4 | -10 |

A Idle
B Fully open
① No.4 groove
② No.2 groove
③ No.3 groove

line | Category | Value | |---|---| | A | N°42 | | B | N°40 | | A (bottom) | N°38 | | B (top) | +5% |
line | X-axis | Y-axis (A) | Y-axis (B) | |---|---|---| | 1/4 | N.42 | +5% | | 1/2 | N.40 | -5% | | 3/4 | N.38 | -5% |

Jet needle adjustment

The jet needle is adjusted by changing it.

Standard jet needleOBELQ* OBELN** OBEKP

* For EUROPE

** For CDN, ZA, AUS and NZ

The tapered sections of all jet needles have the same starting positions, but the needles are available with different straight-portion diameters.

OBELQ - 3

YAMAHA WR250FP - Jet needle adjustment - 1

text_image Clip position Diameter ⓐ of straight portion

Effects of changing the jet needle (reference)

(Diameter of the straight portion)

Changing the diameter of the straight portion adjusts the air-fuel mixture when the throttle is 1/8 to 1/4 open.

YAMAHA WR250FP - Effects of changing the jet needle (reference) - 1

line | Position | Value | |--------|-------| | P | +10 % | | R | -10 % |

A Idle

B Fully open

** Per CDN, ZA, AUS e NZ

other | State | Value | |-------|-------| | P | +10% | | R | -10% |
line | Point | Value | |---|---| | P | +10% | | Q | -10% |
text_image Technical diagram of an internal combustion engine housing with numbered component labels

Leak jet adjustment (accelerator pump adjustment)

The leak jet ① is a setting part that adjusts the flow of fuel discharged by the accelerator pump. Since the accelerator pump operates only when throttle is open, the leak jet is used to adjust a fuel mixture ratio for quick throttle opening and is therefore different from other setting parts that adjust a fuel mixture for each throttle opening (each engine speed).

  1. The engine breathes hard in quick throttle opening.
    Select a leak jet having lower calibrating No. than standard to enrich the mixture.
    #105 → #95
  2. Rough engine operation is felt in quick throttle opening.
    Select a leak jet having higher calibrating No. than standard to lean out the mixture.
    #105 → #115
Standard leak jet#60* #90** #105

* For EUROPE
** For CDN, ZA, AUS and NZ

Relationship with throttle opening

The flow of the fuel through the carburetor main system is controlled by the main jet and then, it is further regulated by the area between the main nozzle and the jet needle.

The fuel flow relates to the diameter of the straight portion of the jet needle with the throttle 1/8 to 1/4 open and relates to the clip position with the throttle 1/8 to 3/4 open.

Therefore, the fuel flow is balanced at each stage of throttle opening by the combination of the jet needle straight portion diameter and clip position.

** Per CDN, ZA, AUS e NZ

Carburetor setting parts

Part nameSizePart number
Main jetRich#1904MX-14943-45
#1884MX-14943-95
#1854MX-14943-44
#1824MX-14943-94
#1804MX-14943-43
#1784MX-14943-93
(STD)#1754MX-14943-42
*(STD)#1724MX-14943-92
**(STD)#1704MX-14943-41
#1684MX-14943-91
#1654MX-14943-40
#1624MX-14943-90
Pilot jetRich#504MX-14948-07
#484MX-14948-06
#454MX-14948-05
#424MX-14948-04
#404MX-14948-03
#384MX-14948-02
#354MX-14948-01
(Jet needle)RichOBELM5NL-14916-EM
OBELN5NL-14916-EN
OBELP5NL-14916-EP
OBELQ5NL-14916-E1
OBELR5NL-14916-ER
OBELS5NL-14916-ES
OBELT5NL-14916-ET
*Jet needleRichOBELS5NL-14916-ES
OBELL5NL-14916-EL
OBELM5NL-14916-EM
OBELN5NL-14916-EN
OBELP5NL-14916-EP
OBELQ5NL-14916-E1
OBELR5NL-14916-ER
** Jet needleRichOBEKL5JG-14916-EL
OBEKM5JG-14916-EM
OBEKN5JG-14916-EN
OBEKP5JG-14916-EP
OBEKQ5JG-14916-E1
OBEKR5JG-14916-ER
OBEKS5JG-14916-ES

* For EUROPE
** For CDN, ZA, AUS and NZ

* For EUROPE
** For CDN, ZA, AUS and NZ

Examples of carburetor setting depending on symptom

SymptomSettingChecking
At full throttleHard breathingShearing noiseWhitish spark plug↓Lean mixtureIncrease main jet calibration no.(Gradually)Discoloration of spark plug →If tan color, it is in good condition.If cannot be corrected:Clogged float valve seatClogged fuel hoseClogged fuel cockCheck that the accelerator pump operates smoothly.
At full throttleSpeed pick-up stopsSlow speed pick-upSlow responseSooty spark plug↓Rich mixtureDecrease main jet calibration no.(Gradually)Discoloration of spark plug →If tan color, it is in good condition.If cannot be corrected:Clogged air filterFuel overflow from carburetor
Lean mixtureLower jet needle clip position.(1 groove down)YAMAHA WR250FP - Relationship with throttle opening - 1The clip position is the jet needle groove on which the clip is installed.The positions are numbered from the top.Check that the accelerator pump operates smoothly. (except for rich mixture symptom).
Rich mixtureRaise jet needle clip position.(1 groove up)
1/4 ~ 3/4 throttleHard breathingLack of speedLower jet needle clip position.(1 groove down)
1/4 ~ 1/2 throttleSlow speed pick-upPoor accelerationRaise jet needle clip position.(1 groove up)
Closed to 1/4 throttleHard breathingSpeed downUse jet needle with a smaller diameter.Slow-speed-circuit passageClogged → Clean.Overflow from carburetor
Closed to 1/4 throttlePoor accelerationUse jet needle with a larger diameter.Raise jet needle clip position. (1 groove up)
Poor response in the low to intermediate speedsRaise jet needle clip position.If this has no effect, lower the jet needle clip position.
Poor response when throttle is opened quicklyCheck overall settings.Use main jet with a lower calibration no.Raise jet needle clip position.(1 groove up)If these have no effect, use a main jet with a higher calibration no. and lower the jet needle clip position.Check air filter for fouling.Check that the accelerator pump operates smoothly.

* This should be taken simply for an example. It is necessary to set the carburetor while checking the operating conditions of the engine.

Selection of the secondary reduction ratio (Sprocket)

Secondary reduction ratio = of rear wheel sprocket teethNumber of drive sprocket teeth

Standard secondary reduction ratio52/13 (4.000)

  • It is generally said that the secondary gear ratio should be reduced for a longer straight portion of a speed course and should be increased for a course with many corners. Actually, however, as the speed depends on the ground condition of the day of the race, be sure to run through the circuit to set the machine suitable for the entire course.
  • In actuality, it is very difficult to achieve settings suitable for the entire course and some settings may be sacrificed. Thus, the settings should be matched to the portion of the course that has the greatest effect on the race result. In such a case, run through the entire course while making notes of lap times to find the best balance; then, determine the secondary reduction ratio.
  • If a course has a long straight portion where a machine can run at maximum speed, the machine is generally set such that it can develop its maximum revolutions toward the end of the straight line, with care taken to avoid the engine over-revving.

NOTE:

Riding technique varies from rider to rider and the performance of a machine also vary from machine to machine. Therefore, do not imitate other rider's settings from the beginning but choose your own setting according to the level of your riding technique.

PARTIE CYCLE

text_image Technical diagram showing gear and chain components with labeled parts ① and ②

EC72N000

Drive and rear wheel sprockets setting parts

Part nameSizePart number
Drive sprocket 1(STD)13T9383B-13218
Rear wheel sprocket 2(STD)48T5GS-25448-50
50T5GS-25450-50
52T5GS-25452-50
54T5PH-25454-50

EC721002

Tire pressure

Tire pressure should be adjust to suit the road surface condition of the circuit.

YAMAHA WR250FP - Tire pressure - 1

Standard tire pressure: 100 kPa (1.0 kgf/cm ^2 , 15 psi)

- Under a rainy, muddy, sandy, or slippery condition, the tire pressure should be lower for a larger area of contact with the road surface.

YAMAHA WR250FP - Tire pressure - 2

Extent of adjustment: 60 \~ 80 kPa (0.6 \~ 0.8 kgf/cm², 9.0 \~ 12 psi)

- Under a stony or hard road condition, the tire pressure should be higher to prevent a flat tire.

YAMAHA WR250FP - Tire pressure - 3

Extent of adjustment: 100 \~ 120 kPa (1.0 \~ 1.2 kgf/cm², 15 \~ 18 psi)

The front fork setting should be made depending on the rider's feeling of an actual run and the circuit conditions.

The front fork setting includes the following three factors:

  1. Setting of air spring characteristics

- Change the fork oil level.

  1. Setting of spring preload

  2. Change the spring.
    • Install the adjustment washer.

  3. Setting of damping force

  4. Change the compression damping.

  5. Change the rebound damping.

The spring acts on the load and the damping force acts on the cushion travel speed.

EC723001

Change in level and characteristics of fork oil

Damping characteristic near the final stroke can be changed by changing the fork oil amount.

CAUTION:

Adjust the oil level in 5 mm (0.2 in) increments or decrements. Too low oil level causes the front fork to produce a noise at full rebound or the rider to feel some pressure on his hands or body. Alternatively, too high oil level will develop unexpectedly early oil lock with the consequent shorter front fork travel and deteriorated performance an characteristics. Therefore, adjust the front fork within the specified range.

A
YAMAHA WR250FP - CAUTION: - 1

line | C [mm (in)] | Curve 1 [kg (lb)] | Curve 2 [kg (lb)] | Curve 3 [kg (lb)] | | ----------- | ----------------- | ----------------- | ----------------- | | 0 | 0 | 0 | 0 | | 1 | ~1 | ~0.5 | ~0.2 | | 2 | ~2 | ~1.5 | ~0.8 | | 3 | ~4 | ~3 | ~1.5 |

YAMAHA WR250FP - CAUTION: - 2

Standard oil level:

140 mm (5.51 in)

* 130 mm (5.12 in)

Extent of adjustment:

80 \~ 150 mm (3.15 \~ 5.91 in)

From top of outer tube with inner tube and damper rod fully compressed without spring.

* For EUROPE

A Air spring characteristics in relation to oil level change
B Load
C Stroke

① Max. oil level
② Standard oil level
③ Min. oil level

text_image A [kg (lb)] ① ② ③

EC727020

Spring preload adjustment

The spring preload is adjusted by installing the adjustment washer ① between the fork spring ② and damper rod ③.

CAUTION:

Do not install three or more adjustment washers for each front fork.

WARNING

Always adjust each front fork to the same setting. Uneven adjustment can cause poor handling and loss of stability.

YAMAHA WR250FP - WARNING - 1

Standard washer quantity: Zero adjustment washers Extent of adjustment: Zero \~ 2 adjustment washers

A Load
B Fork stroke
① Without adjustment washer (standard)
② 1 adjustment washer
③ 2 adjustment washers

EC72A001

Setting of spring after replacement

As the front fork setting can be easily affected by rear suspension, take care so that the machine front and rear are balanced (in position, etc.) when setting the front fork.

1. Use of soft spring

Generally a soft spring gives a soft riding feeling. Rebound damping tends to become stronger and the front fork may sink deeply over a series of gaps.

To set a soft spring:

  • Change the rebound damping. Turn out one or two clicks.
  • Change the compression damping. Turn in one or two clicks.

2. Use of stiff spring

Generally a stiff spring gives a stiff riding feeling. Rebound damping tends to become weaker, resulting in lack of a sense of contact with the road surface or in a vibrating handlebar.

To set a stiff spring:

  • Change the rebound damping.
    Turn in one or two clicks.
  • Change the compression damping.
    Turn out one or two clicks.

A Coverage of spring by weight

B Rider weight

① Soft
② Standard
③ Stiff

2. Ressort dur

text_image Technical diagram of a mechanical assembly with labeled parts and exploded view, including disassembled components and numbered callouts.

EC72P000

Front fork setting parts

- Adjustment washer ①

TYPE (thickness)PART NUMBER
T = 2.3 mm (0.09 in)4SS-23364-L0

- Front fork spring ②

[Equal pitch spring]

TYPESPRING RATESPRING PART NUMBERI.D. MARK (slits)
SOFT0.3804SS-23141-10I-I
0.3904SS-23141-20I-II
0.4004SS-23141-30I-III
**STD0.4104XM-23141-L0-
*STD0.4204SR-23141-L0-
0.4304SS-23141-60III
STD0.4405NL-23141-00-
STIFF0.4505BE-23141-L0-
0.4605BE-23141-00IIIIII
0.4705GR-23141-00II-II

* For EUROPE

** For AUS, NZ and ZA

[Unequal pitch spring]

TYPESPRING RATE (approx.)SPRING PART NUMBERI.D. MARK (slits)
SOFT0.4005ET-23141-20V
0.4105ET-23141-00V-I
0.4205ET-23141-30V-II
0.4305ET-23141-10V-III
STIFF0.4405ET-23141-40V-III

NOTE:

  • The unequal pitch spring is softer in initial characteristic than the equal pitch spring and is difficult to bottom out under full compression.
  • The I.D. mark (slits) ⓐ is proved on the end of the spring.

Rear suspension setting

The rear suspension setting should be made depending on the rider's feeling of an actual run and the circuit conditions.

The rear suspension setting includes the following two factors:

  1. Setting of spring preload

  2. Change the set length of the spring.

  3. Change the spring.

  4. Setting of damping force

  5. Change the rebound damping.

  6. Change the compression damping.

YAMAHA WR250FP - Rear suspension setting - 1

text_image Technical diagram of a bicycle's front suspension system with labeled components and dimension annotation

YAMAHA WR250FP - Rear suspension setting - 2

text_image b

YAMAHA WR250FP - Rear suspension setting - 3

text_image Technical diagram showing mechanical assembly with labeled parts ① and ②, likely illustrating a valve or spring mechanism.

EC72C001

Choosing set length

  1. Place a stand or block under the engine to put the rear wheel above the floor, and measure the length ⓐ between the rear wheel axle center and the rear fender holding bolt.
  2. Remove the stand or block from the engine and with a rider astride the seat, measure the sunken length ⑥ between the rear wheel axle center and the rear fender holding bolt.
  3. Loosen the locknut ① and make adjustment by turning the spring adjuster ② to achieve the standard figure from the subtraction of the length ⑥ from the length ④.

YAMAHA WR250FP - Choosing set length - 1

Standard figure: 90 \~ 100 mm (3.5 \~ 3.9 in)

  • If the machine is new and after it is broken in, the same set length of the spring may change because of the initial fatigue, etc. of the spring. Therefore, be sure to make re-evaluation.
  • If the standard figure cannot be achieved by adjusting the spring adjuster and changing the spring set length, replace the spring with an optional one and make re-adjustment.

Setting of spring after replacement

After replacement, be sure to adjust the spring to the set length [sunken length 90 \~ 100 mm (3.5 \~ 3.9 in)] and set it.

1. Use of soft spring

- Set the soft spring for less rebound damping to compensate for its less spring load. Run with the rebound damping adjuster one or two clicks on the softer side and readjust it to suit your preference.

2. Use of stiff spring

- Set the soft spring for more rebound damping to compensate for its greater spring load. Run with the rebound damping adjuster one or two clicks on the stiffer side and readjust it to suit your preference.

* Adjusting the rebound damping will be followed more or less by a change in the compression damping. For correction, turn the low compression damping adjuster on the softer side.

N.B.:

natural_image Technical line drawing of a mechanical spring assembly with threaded end and mounting base (no text or symbols)

YAMAHA WR250FP - N.B.: - 1

flowchart
graph TD
    A["80 kg"] --> B["(176 lb)"]
    C["70 kg"] --> D["(154 lb)"]
    E["60 kg"] --> F["(132 lb)"]
    G["50 kg"] --> H["(110 lb)"]
    I["40 kg"] --> J["(88 lb)"]
    style A fill:#f9f,stroke:#333
    style B fill:#ccf,stroke:#333
    style C fill:#cfc,stroke:#333
    style D fill:#fcc,stroke:#333
    style E fill:#cff,stroke:#333
    style F fill:#ffc,stroke:#333
    style G fill:#cfc,stroke:#333
    style I fill:#fcc,stroke:#333
    style J fill:#ffc,stroke:#333

CAUTION:

When using a rear shock absorber other than currently installed, use the one whose overall length ⓐ does not exceed the standard as it may result in faulty performance. Never use one whose overall length is greater than standard.

YAMAHA WR250FP - CAUTION: - 1

Length ⓐ of standard shock: 490.5 mm (19.31 in)

A Coverage of spring by weight
B Rider weight
① Soft
② Standard
③ Stiff

ATTENTION:

text_image Technical diagram of a mechanical assembly with labeled parts 1 and a

YAMAHA WR250FP - ATTENTION: - 1

text_image Technical diagram of a mechanical assembly with labeled parts, showing internal components and structural details.

EC72Q000

Rear shock absorber setting parts

- Rear shock spring ①

[Equal pitch spring]

TYPESPRING RATESPRING PART NUMBERI.D. COLOR/ POINTSPRING FREE LENGTH
SOFT4.45DH-22212-70Brown/1260
4.65DH-22212-10Green/1260
*, ** STD4.85DH-22212-20Red/1260
STD5.05NG-22212-60Black/1260
STIFF5.25DH-22212-40Blue/1260
5.45SF-22212-00Yellow/1265
5.65DH-22212-60Pink/1265

* For EUROPE

** For AUS, NZ and ZA

[Unequal pitch spring]

TYPESPRING RATE (approx.)SPRING PART NUMBERI.D. COLOR/ POINTSPRING FREE LENGTH
SOFT4.65NG-22212-20Green/2275
4.85ET-22212-00Red/2275
5.05ET-22212-10Black/2275
5.25ET-22212-30Blue/2275
5.45ET-22212-40Yellow/2275
STIFF5.65NG-22212-50Pink/2280

NOTE:

  • The unequal pitch spring is softer in initial characteristic than the equal pitch spring and is difficult to bottom out under full compression.
  • The I.D. color ⓐ is marked at the end of the spring.

YAMAHA WR250FP - NOTE: - 1

natural_image Technical line drawing of a mechanical spring assembly with labeled dimension (b), showing internal components and mounting bracket (no text or symbols beyond label)

- Extent of adjustment (spring length)

SPRING FREE LENGTHEXTENT OF ADJUSTMENT 6
260 mm (10.24 in)240.5 ~ 258.5 mm(9.47 ~ 10.18 in)
265 mm (10.43 in)245.5 ~ 263.5 mm(9.67 ~ 10.37 in)
275 mm (10.83 in)255.5 ~ 273.5 mm(10.06 ~ 10.77 in)
280 mm (11.02 in)260.5 ~ 278.5 mm(10.26 ~ 10.96 in)
  • If any of the following symptoms is experienced with the standard position as the base, make resetting by reference to the adjustment procedure given in the same chart.
  • Before any change, set the rear shock absorber sunken length to the standard figure 90 \~ 100 mm (3.5 \~ 3.9 in).
SymptomSectionCheckAdjust
JumpLarge gapMedium gapSmall gap
Stiff over entire rangeCompression dampingOil level (oil amount)SpringTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).Replace with soft spring.
Unsmooth movement over entire rangeOuter tubeInner tubeUnder bracket tightening torqueCheck for any bends, dents, and other noticeable scars, etc. If any, replace affected parts.Retighten to specified torque.
Poor initial movementRebound dampingOil sealTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Apply grease in oil seal wall.
Soft over entire range, bottoming outCompression dampingOil level (oil amount)SpringTurn adjuster clockwise (about 2 clicks) to increase damping.Increase oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).Replace with stiff spring.
Stiff toward stroke endOil level (oil amount)Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke end, bottoming outOil level (oil amount)Increase oil level by about 5 mm (0.2 in).
Stiff initial movementCompression dampingTurn adjuster counterclockwise (about 2 clicks) to decrease damping.
Low front, tending to lower front postureCompression dampingRebound dampingBalance with rear endOil level (oil amount)Turn adjuster clockwise (about 2 clicks) to increase damping.Turn adjuster counterclockwise (about 2 clicks) to decrease damping.Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when one passenger is astride seat (lower rear posture).Increase oil level by about 5 mm (0.2 in).
“Obtrusive” front, tending to upper front postureCompression dampingBalance with rear endSpringOil lever (oil amount)Turn adjuster counterclockwise (about 2 clicks) to decrease damping.Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in) when one passenger is astride seat (upper rear posture).Replace with soft spring.Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).

- Rear shock absorber

NOTE:

  • If any of the following symptoms is experienced with the standard position as the base, make resetting by reference to the adjustment procedure given in the same chart.
  • Adjust the rebound damping in 2-click increments or decrements.
  • Adjust the low compression damping in 1-click increments or decrements.
  • Adjust the high compression damping in 1/6 turn increments or decrements.
SymptomSectionCheckAdjust
JumpLarge gapMedium gapSmall gap
Stiff, tending to sinkRebound dampingSpring set lengthTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger is astride seat.
Spongy and unstableRebound dampingLow compression dampingSpringTurn adjuster clockwise (about 2 clicks) to increase damping.Turn adjuster clockwise (about 1 click) to increase damping.Replace with stiff spring.
Heavy and draggingRebound dampingSpringTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Replace with soft spring.
Poor road grippingRebound dampingLow compression dampingHigh compression dampingSpring set lengthSpringTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Turn adjuster clockwise (about 1 clicks) to increase damping.Turn adjuster clockwise (about 1/6 clicks) to increase damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger is astride seat.Replace with soft spring.
Bottoming outHigh compression dampingSpring set lengthSpringTurn adjuster clockwise (about 1/6 turn) to increase damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger in astride seat.Replace with stiff spring.
BouncingRebound dampingSpringTurn adjuster clockwise (about 2 clicks) to increase damping.Replace with soft spring.
Stiff travelHigh compression dampingSpring set lengthSpringTurn adjuster counterclockwise (about 1/6 turn) to decrease damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger is astride seat.Replace with soft spring.
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Product information

Brand : YAMAHA

Model : WR250FP

Category : Off-road motorcycle