YAMAHA WR400F (1999) - Motorcycle

WR400F (1999) - Motorcycle YAMAHA - Free user manual and instructions

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USER MANUAL WR400F (1999) YAMAHA

OWNER'S SERVICE MANUAL

MANUEL D'ATELIER DU

PROPRIETAIRE

FAHRER- UND

WARTUNGS-HANDBUCH

MANUAL DE SERVCIO

DEL PROPIETARIO

WR400F(M)

EC010010

WR400F(M)

OWNER'S SERVICE MANUAL

1999 by Yamaha Motor Co., Ltd. 1st Edition, November 1999

All rights reserved. Any reprinting or unauthorized use without the written permission of Yamaha Motor Co., Ltd. is expressly prohibited.

Printed in Japan

WR400F(M)

MANUEL D'ATELIER DU PROPRIETAIRE

1999 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As improvements are made on this model, some data in this manual may become outdated.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.
  2. THIS MACHINE IS DESIGNED TO BE RIDDEN BY THE OPERATOR ONLY. Do not carry passengers on this machine.
  3. 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.
  4. 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.

NOTICE IMPORTANTE

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.

  1. GASOLINE CAN CAUSE INJURY.

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 VENTILATION.

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.

10.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 EST HAUTEMENT INFLAMMABLE.

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

HOW TO USE THIS MANUAL

EC081000 PARTICULARLYIMPORTANT INFORMATION

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

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 WR400F (1999) - NOTE: - 1

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.

COMMENTUTILISER CE MANUEL

INFORMATIONS PARTICULIEREMENT IMPOR TANTES

CÓMOURILIZAR ESTE MANUAL

INFORMACION ESPECIALMENTE IMPOR-TANTE

El@simbolo dc alerta significa: DEBE PRESTAR ATENCION YA QUE ESTA EN JUEGO SU PROPIA SEGURIDAD!

ADVERTENCIA

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 WR400F (1999) - HOW TO READ DESCRIPTIONS - 1

FORMATDU MANUEL

(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
Filling fluid
① Lubricant
⑫ Tightening
⑬ Specified value, Service limit
④ Resistance () ,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
⑦ Apply lightweight lithium-soap base grease
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)
Use new one

SYMBOLS GRAPHIQUES

REGULAR INSPECTION AND ADJUSTMENT

ENGINE

CHASSIS

ELECTRICAL

TUNING

INDEXINDEXINDEX
RENSEIGNEMENTS-GENERAUXALLGEMEINEANGABENINFORMACIONGENERALGEN1
CARACTERISTI-QUESTECHNISCHEDATENESPECIFICACIONES2
CONTROLES ETREGLAGESCOURANTSREGELMÄSSIGINESPRESECTION UNDEINSTELLARBEITENAJUSTES EINSPECCIONREGULARES3
MOTEURMOTORMOTOR4
PARTIE CYCLEFAHRWERKCHASIS5
PARTIE ELECTRIQUEELEKTRISCHANEANLAGESISTEMAELECTRICO6
MISES AU POINTABSTIMMUNGPUESTA A PUNTO7

CONTENTS

CHAPTER 1

GENERAL INFORMATION

DESCRIPTION 1-1
MACHINE IDENTIFICATION 1-2
IMPORTANT INFORMATION 1-3
CHECKING OF CONNECTION 1-5
SPECIAL TOOLS 1-6
CONTROL FUNCTIONS 1-9
FUEL 1-12
STARTING AND BREAK-IN 1-13
TORQUE-CHECK POINTS 1-17
CLEANING AND STORAGE 1-18

CHAPTER 2

SPECIFICATIONS

GENERAL SPECIFICATIONS 2-1
MAINTENANCE SPECIFICATIONS 2-4
GENERAL TORQUE
SPECIFICATIONS 2-18
DEFINITION OF UNITS 2-18
LUBRICATION DIAGRAMS 2-19
CABLE ROUTING DIAGRAM 2-21

CHAPTER 3

REGULAR INSPECTION AND

ADJUSTMENTS

MAINTENANCE INTERVALS 3-1
PRE-OPERATION INSPECTION AND
MAINTENANCE 3-4
ENGINE 3-5
CHASSIS 3-25
ELECTRICAL 3-46

TABLES DES MATIRES

CHAPITRE 1 RENSEIGNEMENTS GENERAUX

DESCRIPTION 1-1

IDENTIFICATION DE LA

MACHINE 1-2

INFORMATIONS

IMPORTANT 1-3

VERIFICATION DES

CONNEXIONS 1-5

OUTILS SPECIAUX

FONCTIONS DES

COMMANDES 1-9

ESSENCE 1-12

MISE EN MARCHE

ETRODAGE 1-13

POINTS DE VERIFICATION DE

COUPLE DE SERRAGE. 1-17

NETTOYAGE

ET RANGEMENT 1-18

CHAPITRE 2 CHARACTERISTIQUES

CHARACTERISTIQUES

GENERALES 2-1

CHARACTERISTIQUES

D'ENTRETIEN 2-4

CHARACTERISTIQUES

GENERALES DE COUPLE 2-18

DEFINITION DES UNITES 2-18

SCHEMAS DE GRAISSAGE 2-19

CHEMINEMENT

DES CABLES 2-21

CHAPITRE 3 CONTROLES ET REGLAGES COURANTS

PROGRAMME D'ENTRETIEN ...3-1

CONTROLE ET ENTRETIEN

AVANT UTILISATION 3-4

MOTEUR 3-5

PARTIE CYCLE 3-25

PARTIE ELECTRIQUE 3-46

INHALT

VALVES AND VALVE SPRINGS 4-30

CYLINDER AND PISTON 4-38

CLUTCH 4-44

OIL FILTER, WATER PUMP AND

CRANKCASE COVER (RIGHT) 4-50

BALANCER 4-56

OIL PUMP 4-59

KICK AXLE AND SHIFT SHAFT 4-63

CDIMAGNETO 4-70

ENGINE REMOVAL 4-74

CRANKCASE AND CRANKSHAFT 4-79

TRANSMISSION, SHIFT CAM AND

SHIFT FORK 4-88

CHAPTER 5 CHASSIS

FRONT WHEEL AND REAR WHEEL 5-1

SELLE, RESERVOIR A ESSENCE

AXE DE DEMARREUR AU PIED

ET ARBRE DE SELECTEUR ...4-63

MAGNETO CDI 4-70

DEPOSE DU MOTEUR 4-74

CARTER ET VILEBREQUIN...4-79

BOITE A VITESSES, TAMBOUR

ET FOURCHETTE

DE SELECTION 4-88

KAPITEL 4 MOTOR

SITZBANK, KRAFTSTOFFTANK

BUSTIBLE Y CUBIERTAS

LATERALES 4-1

TUBO DE ESCAPE Y

SILENCIADOR 4-2

RADIADOR 4-3

CARBURADOR 4-7

ARBOLES DE LEVAS 4-20

CULATA 4-27

VALVULASYMUELLES

DEVALVULA 4-30

CILINDRO Y PISTON 4-38

EMBRAGUE 4-44

FILTRO DE ACEITE, BOMBA DE

AGUA Y CUBIERTA

DEL CARTER (DERECHO) ....4-50

COMPENSADOR 4-56

CHAPITRE 7 MISES AU POINT

MOTEUR 7-1

PARTIE CYCLE 7-10

KAPITEL 6

ELEKTRISCHE

ANLAGE

TPS-SYSTEM (DROSSELKLAP

PEN-POSITIONSSENSOR) 6-7

LICHTANlage 6-11

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

YAMAHA WR400F (1999) - ANLAGE - 1

YAMAHA WR400F (1999) - ANLAGE - 2

YAMAHA WR400F (1999) - ANLAGE - 3

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 WR400F (1999) - VEHICLE IDENTIFICATION NUMBER - 1

YAMAHA WR400F (1999) - VEHICLE IDENTIFICATION NUMBER - 2

YAMAHA WR400F (1999) - VEHICLE IDENTIFICATION NUMBER - 3

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

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

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

  3. 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.

  4. 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.

  5. Keep away from fire.

EC132000

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.

INFORMATIONS IMPOR TANTES

PREPARATION POUR LA DEPOSE ET DEMONTAGE

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 WR400F (1999) - GASKETS, OIL SEALS AND O-RINGS - 1

YAMAHA WR400F (1999) - GASKETS, OIL SEALS AND O-RINGS - 2

YAMAHA WR400F (1999) - GASKETS, OIL SEALS AND O-RINGS - 3

YAMAHA WR400F (1999) - GASKETS, OIL SEALS AND O-RINGS - 4

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.

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

JOINTS, BAGUES D'ETANCHEITE ET JOINTS TORIQUES

CHECKING OF CONNECTION

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

  1. Disconnect:

  2. Connector

  3. Dry each terminal with an air bower.

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

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

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

  7. Connect:

  8. Connector

NOTE:

The two connectors "click" together.

  1. Check for continuity with a tester.

NOTE:

  • If there is no continuity, clean the terminals.

  • Be sure to perform the steps 1 to 7 listed above when checking the wireharness.

  • 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-" or "YU-".
For others, use part number starting with "90890-".

Part number Tool name/How to use Illustration
YU-01135-A, 90890-01135YM-01305, 90890-01305Crankcase separating toolCrankcase separating boltThese tools are used to split the crankcase as well asremove the crankshaft from either case.YU-01135-AYM-0130590890-0113590890-01305
YU-01235, 90890-01235 Rotor holding toolThis tool is used when loosening or tightening the fly-wheel magneto securing nut.YU-01235 90890-01235
YU-03097, 90890-01252YU-01256Dial gauge and standStandThese tools are used to check each part for runout or bend.YU-03097YU-0125690890-01252
YU-90050, 90890-01274YU-90050, 90890-01275YU-91044, 90890-04081YU-90062, 90890-01277Crankcase installing toolPotBoltSpacerAdapterThese tools are used to install the crankshaft.YU-90050YU-90062YU-9104490890-0127490890-0127590890-0127790890-04081
YU-01304, 90890-01304 Piston pin pullerThis tool is used to remove the piston pin.YU-01304 90890-01304
YU-24460-1, 90890-01325YU-33984, 90890-01352Radiator cap testerAdapterThese tools are used for checking the cooling system.YU-24460-01YU-3398490890-0132590890-01352
YU-33270, 90890-01362 Flywheel pullerThis tool is used to remove the flywheel magneto.YM-33270 90890-01362
Part number Tool name/How to use illustration
YM-33975, 90890-01403 Ring nut wrenchThis tool is used when tighten the steering ring nut to specification.YM-33975 90890-01403
YM-1423, 90890-01423 Damper rod holderUse this tool to remove and install the damper rod.YM-1423 90890-01423
YM-01442, 90890-01442 Fork seal driverThis tool is used when install the fork oil seal.YM-01442 90890-01442
YU-03112, 90890-03112 Yama hah a pocket testerUse this tool to inspect the coil resistance, output voltage and amperage.YU-03112 90890-03112
YU-8036-190890-03113Inductive tachometerEngine tachometerThis tool is needed for observing engine rpm.YU-8036-1 90890-03113
YM-33277-A, 90890-03141Timing lightThis tool is necessary for checking ignition timing.YM-33277-A 90890-03141
YM-04019, 90890-04019YM-04108, 90890-04108Valve spring compressorAttachmentThis tool needed to remove and install the valve assemblies.YM-04019YM-0410890890-0401990890-04108
YM-91042, 90890-04086 Clutch holding toolThis tool is used to hold the clutch when removing or installing the clutch boss securing nut.YM-91042 90890-04086
YM-4116, 90890-04116YM-4097, 90890-04097Valve guide removerIntake (4.5 mm)Exhaust (5.0 mm)This tool is needed to remove and install the valve guide.YM-4116YM-409790890-0411690890-04097
Part number Tool name/How to use Illustration
YM-4117, 90890-04117 YM-4098, 90890-04098Valve guide installer Intake Exhaust This tool is needed to install the valve guide.YM-4117 YM-409890890-04117 90890-04098
YM-4118, 90890-04118 YM-4099, 90890-04099Valve guide reamer Intake (4.5 mm) Exhaust (5.0 mm) This tool is needed to rebore the new valve guide.YM-4118 YM-409990890-04118 90890-04099
YM-34487 90890-06754Dynamic spark tester Ignition checker This instrument is necessary for checking the ignition system components.YM-34487 90890-06754
ACC-11001-05-01 90890-85505Quick gasket YAMAHA Bond No. 1215 This sealant (Bond) is used for crankcase mating surface, etc.ACC-11001-05-01 90890-85505

OUTILS SPECIAUX

The "ENGINE STOP" button ① is located on the left handlebar. Continue pushing the "ENGINE STOP" button 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.

EC154000

KICK STARTER

Rotate the kick starter 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 kick starter so the engine can be started in any gear if the clutch is disengaged. In normal practices, however, shift to neutral before starting.

FONCTIONS DES COMMANDES

BOUTON D'ARRET DE MOTEUR "ENGINE STOP"

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 WR400F (1999) - BOUTON D'ARRET DE MOTEUR "ENGINE STOP" - 1

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 WR400F (1999) - THROTTLE GRIP - 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 WR400F (1999) - FRONT BRAKE LEVER - 1

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 and also filters the fuel. The fuel cock has 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:With the lever in this position fuel flows to the carburetor from the reserve section of the fuel tank after the main supply of the fuel has been depleted. Normal riding is possible with the lever is in this position, but it is recommended to add fuel as soon as possible.

YAMAHA WR400F (1999) - ATTENTION: - 1

EC159000

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 WR400F (1999) - COLD STARTER KNOB - 1

HOT STARTER KNOB (red)

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.

FONCTIONS DES COMMANDES ARMATUREN UND DEREN FUNKTION FUNCIONES DE CONTROL

ROBINET A ESSENCE

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 motorcycle 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.

FUEL

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

YAMAHA WR400F (1999) - FUEL - 1

Except for AUS:

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

For AUS:

Unleaded fuel only

NOTE:

Except for AUS:

  1. If knocking or pinging occurs, use a different brand of gasoline or higher octane grade.
  2. If unleaded gasoline is not available, then leaded gasoline can be used.

CLAPET ANTIRETOUR DE TUYAU DE RENIFLARD

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.

EC191001

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 kick starter until the compression stroke is found. When considerable resistance of the kick starter is felt, the engine is on the compression stroke. If the engine is on the exhaust stroke, resistance will only be felt when the kick starter is initially depressed, not through the entire range of depression (as when the engine is on the compression stroke); therefore, depress the kick starter a few more times.

Do not open the throttle while kicking the kick starter. Otherwise, the kick starter may kick back.
8. 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 ARRANQUEYRODAJE

Do not operate the cold starter knob and throttle. Open the hot starter knob (red) and start the engine by kicking the kick starter 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 10 to 20 times to clear the engine.

Then, restart the engine.

Refer to "Restarting an engine after a fall".

Throttle grip oper- ation*Cold starter knobHot starter knob (red)
Starting a cold engineAir temperature = less than 5 °C (41 °F)Open 3 or 4 timesON OFF
Air temperature = more than 5 °C (41 °F)None ONOFF
Air temperature (normal temperature) = between 5 °C (41 °F) and 25 °C (77 °F)None ONOFF OFFOFF
Air temperature = more than 25 °C (77 °F)None OFFOFF
Starting an engine after a long period of timeNone ONOFF
Restarting a warm engine NoneOFF ON
Restarting an engine after a fallNone OFFON
  • 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" button. 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

PISTON, ANILLO, VALVULAS, ARBOLES DE LEVAS Y ENGRAJNES:

Combined seat and tank

Frame to rear frame

Fuel tank to frame

Silencer to rear frame

Engine mounting


Frame to engine

Steering Steering shaft to

handlebar

Steering shaft to frame

Steering shaft to handle crown

Handle crown to handlebar

Suspension Front-Steering shaft to

front fork

Front fork to handle crown

Front fork to under bracket

Rear Installation of shock

absorber

Shock absorber to frame

Wheel Installation of wheel Front

Rear

Tightening of pivot shaft

Tightening of rear axle

Wheel to sprocket

Brake Front

Rear

Caliper to front fork

Brake disc to wheel

Tightening of union bolt

Master cylinder to handlebar

Tightening of air bleeder

Brake disc to wheel

Tightening of union bolt

Master cylinder to frame

Tightening of air bleeder

Fuel system

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 WR400F (1999) - POINTS DE VERIFICATION DE COUPLE DE SERRAGE - 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 trust.
  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: WR400F (EUROPE)WR400FM (USA) WR400F(M) (CDN, AUS, NZ, ZA)
Model code number: 5GS5 (USA)5GS6 (EUROPE) 5GS8 (CDN, AUS, NZ, ZA)
Dimensions: Overall length 2,171 mm (85.5 in) Overall width 827 mm (32.6 in) Overall height 1,303 mm (51.3 in) Seat height 998 mm (39.3 in) Wheelbase 1,490 mm (58.7 in) Minimum ground clearance 373 mm (14.7 in)
Basic weight: With oil and full fuel tank 122.0 kg (270 lb)
Engine: Engine type Liquid cooled 4-stroke, DOHC Cylinder arrangement Single cylinder, forward Displacement 399 cm Bore · stroke 92.0 Compression ratio 12.5 : 1 Starting systeminclined 3 (14.1 Imp oz, 13.5 US oz) · 60.1 mm (3.62 · 2.37 in) Kick starter
Lubrication system:Dry sump
Oil type or grade: Engine oil Temp. 30 40 50 60°F A B 0 5 10 15°C[For USA and CDN] 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) [Except for USA and CDN] API “SH” or higher grade (Designed primarily for motorcycles)

GENERAL SPECIFICATIONS

Oil capacity:Engine oilPeriodic 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)Total amount 1.7 L (1.50 Imp qt, 1.80 US qt)
Coolant capacity (including all routes): 1.2 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
Fuel:Type Premium unleaded fuel with a research octaneTank capacity 12 L (2.64 Imp gal, 3.17 US gal)Reserve 8 L (1.76 Imp gal, 2.11 US gal)number of 95 or higher. (Except for AUS)Unleaded fuel only (For AUS)(For USA, CDN)(Except for USA, CDN)1.6 L (0.35 Imp gal, 0.42 US gal)(For USA, CDN)1.4 L (0.31 Imp gal, 0.37 US gal)(Except for USA, CDN)
Carburetor:Type FCR-MX39Manufacturer KEIHIN
Spark plug:Type/manufacturer CR8E/NGKGap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)U24ESR-N/DENSO
Clutch type: Wet, multiple-disc
Transmission:Primary reduction systemPrimary reduction ratioSecondary reduction systemSecondary reduction ratioTransmission typeOperationGear ratio: 1st2nd3rd4th5thGear62/21 (2.952)Chain drive50/14 (3.571)Constant mesh, 5-speedLeft foot operation29/12 (2.416)26/15 (1.733)21/16 (1.312)21/20 (1.050)21/25 (0.840)
Chassis:Frame typeCaster angleTrailSemi double cradle27.8°123 mm (4.84 in)

GENERAL SPECIFICATIONS

YAMAHA WR400F (1999) - GENERAL SPECIFICATIONS - 1

Tire: Type With tube Size (front) 80/100-21 51M (USA, CDN, ZA) Size (rear) 110/100-18 64M (USA, CDN, ZA) Tire pressure (front and rear) 100 kPa (1.0 kg/cm2)90/90-21 54R (EUROPE, AUS, NZ) 120/90-18 65R (EUROPE, AUS, NZ) 2, 15 psi)
Brake: Front brake type Single disc brake Operation Right hand operation Rear brake type Single disc brake Operation Right foot operation
Suspension: Front suspension Telescopic fork Rear suspension Swingarm (link type monocross suspension)
Shock absorber: Front shock absorber Coil spring/oil damper Rear shock absorber Coil spring/gas, oil damper
Wheel travel: Front wheel travel 300 mm (11.8 in) Rear wheel travel315 mm (12.4 in)
Electrical: Ignition systemCDI magneto

MAINTENANCE SPECIFICATIONS

ENGINE

Item Standard Limit
Cylinder head: Warp limit --- 0.05 mm(0.002 in)
Cylinder: Bore size 92.00 ~ 92.01 mm(3.6220 ~ 3.6224 in)----
Out of round limit ---- 0.05 mm(0.002 in)
Camshaft: Drive method Chain drive (Left) ----
Camshaft cap inside diameter 22.000 ~ 22.021mm----
Camshaft bearing diameter 21.967 ~ 21.980 mm(0.8661 ~ 0.8670 in)----
Camshaft-to-cap clearance 0.020 ~ 0.054 mm(0.8648 ~ 0.8654 in)0.08 mm
Cam dimensions(0.0008 ~ 0.0021 in)(0.003 in)
Intake "A" 31.7 ~ 31.8 mm(1.248 ~ 1.252 in)31.6 mm
"B" 22.95 ~23.05 mm(1.244 in)
Exhaust "A" 31.2 ~ 31.3 mm(0.9035 ~ 0.9075 in)22.85 mm
"B" 22.95 ~1.3 mm(0.900 in)
Camshaft runout limit(1.2283 ~ 1.2323 in)31.1 mm
Camshaft runout limit(0.9035 ~ 0.9075 in)(1.224 in)
Camshaft runout limit---- 0.03 mm22.85 mm
Camshaft runout limit---- 0.03 mm(0.900 in)
ItemStandardLimit
Cam chain: Cam chain type/No. of links 92RH2010-120MPX/120 ---
Cam chain adjustment method Automatic ---
Valve, valve seat, valve guide: Valve clearance (cold) IN 0.15 ~ 0.20 mm EX 0.25 ~ 0.30 mm (0.0098 ~ 0.0118 in)(0.0059 ~ 0.0079 in) (0.0098 ~ 0.0118 in)--- ---
Valve dimensions:
Head DiameterFace WidthSeat WidthMargin Thickness
“A” head diameter IN 26.9 ~ 27.1 mm(1.0591 ~ 1.0669 in) (1.0984 ~ 1.1063 in)--- ---
“B” face width IN 2.26 mm (0.089 in) ---(0.089 in) ---
“C” seat width IN 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in) 1.5 mm(0.0591 in)
“D” margin thickness IN 1 mm (0.0394 in) 0.85 mm(0.0591 in)
Stem outside diameterIN 4.475 ~ 4.90 mm (0.1762 ~ 0.1768 in)(0.033 in)
Guide inside diameterIN 4.960 ~ 4.975 mm (0.1953 ~ 0.1959 in)(0.033 in)
IN 4.500 ~ 4.512 mm (0.1772 ~ 0.1776 in)---
EX 5.000 ~ 5.012 mm (0.1969 ~ 0.1973 in)---
Stem-to-guide clearance IN 0.010 ~ 0.037 mm0.08 mm (0.003 in)
Ex 0.025 ~(0.0004 ~ 0.0015 in) 0.052 mm (0.0010 ~ 0.0020 in)0.10 mm (0.004 in)

MAINTENANCE SPECIFICATIONS

ItemStandardLimit
Stem runout limit----0.01 mm Valve seat width IN 0.9~1.1 mm (0.0354~0.0433 in)----EX 0.9~1.1 mm (0.0354~0.0433 in)----(0.0004 in)
Valve spring: Free length IN 40.37 mm (1.59 in) 39.4 mm EX 42.66 mm (1.68 in) 41.7 mm Set length (valve closed) IN 32.86 mm (1.29 in)----EX 35.38 mm (1.39 in)----(1.55 in) (1.64 in)----
Compressed pressure (installed) IN 117~134 N EX 126~138 N Tilt limit*N----2.5*/1.8 mm EX----2.5*/1.9 mm(11.9~13.7 kg, 26.23~30.20 lb) (12.9~14.1 kg, 28.44~31.08 lb) (2.5*/0.067 in) (2.5*/0.075 in)
Direction of winding (top view) IN Clockwise----EXClockwise
Piston: Piston to cylinder clearance Piston size "D" H D0.040~0.065 mm (0.0016~0.0026 in) 91.945~91.960 mm (3.6199~3.6205 in)
Measuring point "H" Piston off-set9 mm (0.354 in) 1 mm (0.0394 in)

MAINTENANCE SPECIFICATIONS

YAMAHA WR400F (1999) - MAINTENANCE SPECIFICATIONS - 1

ItemStandardLimit
Piston pin bore inside diameter 18.004 ~ 18.015 mm(0.7088 ~ 0.7093 in)----
Piston pin outside diameter 17.991 ~ 18.000 mm(0.7083 ~ 0.7087 in)----
Piston rings:Top ringType Barrel ----Dimensions (B·T) 1.2End gap (installed) 0.20 ~ 0.35 mmSide clearance (installed) 0.030 ~ 0.065 mm2nd ringType T BDimensions (B·T) 1.00End gap (installed) 0.40 ~ 0.55 mmSide clearance 0.020 ~ 0.055 mmOil ringDimensions (B·T) 2.0End gap (installed) 0.2 ~ 0.5 mm (0.01 ~ 0.02 in) ----· 3.5 mm (0.05 · 0.14 in) ----(0.008 ~ 0.014 in)(0.0012 ~ 0.0026 in)· 3.35 mm (0.04 · 0.13 in) ----(0.016 ~ 0.022 in)(0.0008 ~ 0.0022 in)· 2.9 mm (0.08 · 0.11 in) ----0.7 mm(0.028 in)0.13 mm(0.005 in)0.8 mm(0.031 in)0.13 mm(0.005 in)
Crankshaft:Crank width "A" 61.95 ~ 62.00 mmRunout limit "C" 0.03 mm (0.0012 in)Big end side clearance "D"Small end free play "F"(2.439 ~ 2.441 in)0.05 mm0.15 ~ 0.45 mm(0.0059 ~ 0.0177 in)0.4 ~ 1.0 mm (0.02 ~ 0.04 in) 2.0 in----(0.002 in)0.50 mm(0.02 in)mm(0.08 in)
Balancer:Balancer drive methodGear----
Decompression device:TypeCable free playManual5 ~ 9 mm (0.20 ~ 0.35 in)----
Air filter oil grade:Engine oil----

MAINTENANCE SPECIFICATIONS

SPEC
ItemStandardLimit
Clutch: Friction plate 1 thickness 2.72 ~ 2.88 mm Inner diameterø112 mm (4.41 in)---- Quantity 7---- Friction plate 2 thickness 2.92 ~ 3.08 mm Inner diameterø116 mm (4.57 in)---- Quantity 1---- Clutch plate thickness 1.1 ~ 1.3 mm (0.043 ~ 0.051 in)---- Quantity 7---- Warp limit---- 0.2 mm Clutch spring free length 44 mm (1.73 in) 43 mm Quantity 5---- Clutch housing thrust clearance 0.20 ~ 0.45 mm Clutch housing radial clearance 0.010 ~ 0.044 mm Clutch release method Inner push, cam push(0.107 ~ 0.113 in) (0.115 ~ 0.121 in) (0.051 in)----2.5 mm (0.98 in) 2.7 mm (0.106 in) (0.008 in) (1.69 in) ---- ---- (0.002 in)
Shifter: Shifter type Guide bar bending limitCam drum and guide bar---- 0.05 mm---- (0.002 in)
Kick starter: TypeRatchet type----
Carburetor:USAEUROPE, CDN,AUS, NZ, ZA
I. D. mark5GS5 505GS6 60----
Main jet(M.J)#165----
Main air jet(M.A.J)#200----
Jet needle(J.N)OBDRS-3OBRQ-4----
Cutaway(C.A)15----
Pilot air jet 1(P.A.J.1)#75----
Pilot air jet 2(P.A.J.2)#90----
Pilot outlet(P.O)0.9----
Pilot jet(P.J)#42----
Pilot screw (example)(P.S)1-5/81-1/2----
Bypass 1(B.P.1)1.0----
Valve seat size(V.S)3.8----
Starter jet 1(G.S.1)#65----
Float height(F.H)8 mm (0.31 in)----
Engine idle speed1,700 ~1,900 r/min----
Intake vacuum33.3 ~ 38.7 kPa(250 ~ 290 mmHg,9.84 ~ 11.42 inHg)----

MAINTENANCE SPECIFICATIONS

YAMAHA WR400F (1999) - MAINTENANCE SPECIFICATIONS - 1

ItemStandard Limit
Lubrication system: Oil filter type Wire mesh type ---- Oil pump type Trochoid type ---- Tip clearance “A” 0.07 ~ 0.12 mm “B” 0.09 ~ 0.15 mm Side clearance 0.03 ~ 0.08 mm Bypass valve setting pressure 40 ~ 80 kPa (0.4 ~ 0.8 kg/cm2, 5.69 ~ 11.38 psi)(0.0028 ~ 0.0047 in) (0.0035 ~ 0.0059 in) (0.0012 ~ 0.0031 in)0.15 mm (0.006 in) 0.22 mm (0.009 in) 0.15 mm (0.006 in)
Cooling: Radiator core size Width 117.8 mm (4.6 in) ---- Height 260 mm (10.2 in) ---- Thickness 32 mm (1.26 in) ---- Radiator cap opening pressure110 kPa (1.1 kg/cm2, 15.6 psi)----
Radiator capacity (total)0.76 L (0.67 Imp qt, 0.80 US qt)----
Water pump TypeSingle-suction centrifugal pump----
Item Standard
Lubrication chart:
Pressure feedOil tank
Splashed scavengeCamshaft
Cylinder headValve lifter
Transmission gearsPiston
Main axlePiston pin
Drive axleOil filter Crank pin
Check ballOil pump rotor 1
Oil pump rotor 2Oil pump rotor 2
Oil strainerOil pan
Part to be tightened Thread size Q'tyTightening torque
Nm mkg ft·lb
Spark plug M10· 1.0 113 1.3 9.4
Camshaft cap M6· 1.0 1010 1.0 7.2
Cylinder head (stud bolt) M6· 1.0 270.75.1
(bolt)M8 · 1.25 315 1.5 11
(nut)M10 · 1.254 444.4 32
(Cylinder head cover)M6 · 1.0 210 1.0 7.2
Decompression shaftM8 · 1.25 220 2.0 14
Decompression cable guideM6 · 1.0 210 1.0 7.2
Exhaust pipe (nut)M6 · 1.0 110 1.0 7.2
(bolt)M6 · 1.0 210 1.0 7.2
Tensioner cap boltM6 · 1.0 170.75.1
Timing chain guide (rear)M6 · 1.0 210 1.0 7.2
Decompression shaftM6 · 1.0 170.75.1
Decompression cable guideM6 · 1.0 110 1.0 7.2
Exhaust pipe (nut)M8 · 1.25 113 1.3 9.4
(Bolt)M8 · 1.25 124 2.4 17
SilencerM8 · 1.25 235 3.5 25
Silencer clampM8 · 1.25 120 2.0 14
Exhaust pipe protectorM6 · 1.0 310 1.0 7.2
Spark arrester (For USA)M6 · 1.0 310 1.0 7.2
Clamp (air cleaner joint)M5 · 0.8 130.32.2
Clamp (carburetor joint)M4 · 0.7 130.32.2
Air filter joint clampM6 · 1.0 120.21.4
Throttle cable coverM5 · 0.8 140.42.9
Air filter elementM6 · 1.0 120.21.4
Radiator panel (upper)M6 · 1.0 210 1.0 7.2
(For EUROPE, AUS, NZ, ZA)
RadiatorM6 · 1.0 610 1.0 7.2
Radiator hose clampM6 · 1.0 820.21.4
ImpellerM8 · 1.25 114 1.4 10
Water pump housing coverM6 · 1.0 310 1.0 7.2
Coolant drain boltM6 · 1.0 110 1.0 7.2
Oil pump coverM5 · 0.8140.42.9
Oil pumpM6 · 1.0 310 1.0 7.2
Engine oil drain bolt (oil filter)M6 · 1.0 110 1.0 7.2
Oil filter coverM6 · 1.0 210 1.0 7.2
Oil delivery pipe 1M10 · 1.251202.014
M8 · 1.252181.813
Oil hose clamp-220.21.4
Clutch coverM6 · 1.0 710 1.0 7.2
Crankcase cover (right)M6 · 1.0 1010 1.0 7.2
Crankcase cover (left)M6 · 1.0 810 1.0 7.2
CrankcaseM6 · 1.0 1212 1.2 8.7
Oil drain bolt (crankcase)M12 · 1.5 120 2.0 1 4

MAINTENANCE SPECIFICATIONS

YAMAHA WR400F (1999) - MAINTENANCE SPECIFICATIONS - 1

Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
Oil drain bolt (frame) M8 · 1.25 1 23 2.3 17
Oil strainer (frame) M18 · 1.5 1 90 9.0 65
Crankcase bearing stopper M6 · 1.0 15 10 1.0 7.2
Drive axle oil seal stopper M6 · 1.0 2 10 1.0 7.2
Ratchet wheel guide M6 · 1.0 2 12 1.2 8.7
Kick crank M8 · 1.25 1 33 3.3 24
Primary drive gear M20 · 1.0 1 75 7.5 54
Clutch boss M20 · 1.0 1 75 7.5 54
Clutch spring M6 · 1.0 5 8 0.8 5.8
Balancer driven gearM14 · 1.0 150 5.0 36
Balancer weight plateM6 · 1.0 310 1.0 7.2
Drive sprocketM20 · 1.0 175 7.5 54
Shift guideM6 · 1.0 210 1.0 7.2
Stopper leverM6 · 1.0 110 1.0 7.2
SegmentM8 · 1.25 130 3.0 22
Neutral switchM5 · 0.8240.42.9

EC212201
CHASSIS

Item Standard Limit
Steering system: Steering bearing type Taper roller bearing ---
Front suspension: USA, CDNAUS, NZ, ZAEUROPE
Front fork travel 300 mm(11.8 in)← ---
Fork spring free length 460 mm(18.1 in)← 455 mm (17.9 in)
Spring rate, STD K = 4.6 N/mm(0.46 kg/mm, 25.8 lb/in)K = 4.2 N/mm (0.42 kg/mm, 23.5 lb/in)---
Optional spring/spacer Yes ← ----3583 cm³---
Oil capacity 573 cm(20.2 Imp oz, 19.4 US oz)(20.5 Imp oz, 19.7 US oz)---
Oil level 135 mm(5.31 in)125 mm---
<Min.~Max.> (From top of outer tube with inner tube and damper rod fully compressed without spring.)80 ~ 150 mm(4.92 in)
Oil grade Suspension oil(3.15 ~ 5.91 in)
Inner tube outer diameter“01”---
Front fork top end46 mm (1.81 in)Zero mm---
5 mm(Zero in)
(0.20 in)
Rear suspension: USA, CDN,AUS, NZ, ZAEUROPE
Shock absorber travel132 mm← ---
(5.20 in)
Spring free length260 mm← ---
(10.24 in)
Fitting length245 mm244 mm---
(9.65 in)(9.61 in)
<Min.~Max.>242 ~ 260 mm---
(9.53 ~ 10.24 in)
Spring rate, STD K = 50.0 N/mm(5.00 kg/mm, 280.0 lb/in)K = 48.0 N/mm---
Yes ←-----
Optional springYes ←-----
Enclosed gas pressure1,000 kPa(10 kg/cm², 142 psi)
Swingarm: Swingarm free play limit----1.0 mm (0.04 in)
End

MAINTENANCE SPECIFICATIONS

ItemStandard Limit
Wheel: Front wheel type Spoke wheel ---Rear wheel type Spoke wheel ---Front rim size/material 21 · 1.60/Aluminum ---Rear rim size/material 18 · 2.15/Aluminum ---Rim runout limitRadial --- 2.0 mm (0.08 in)Lateral --- 2.0 mm (0.08 in)
Drive chain: Type/manufacturer 520VM/DAIDO ---Number of links 113 links + joint ---Chain slack 40 ~ 50 mm (1.6 ~ 2.0 in) ---Chain length (10 links)---150.1 mm (5.91 in)
Front disc brake: Disc outside diameter · Thickness245 · 3.0 mm (9.65 · 0.12 in)245 · 2.5 mm(9.65 · 0.08 in)
Deflection limit---- 0.15 mm (0.006 in)1 mm (0.04 in)
Pad thickness4.4 mm (0.17 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 diameter · Thickness240 · 4.0 mm (9.45 · 0.16 in)240 · 3.5 mm(9.45 · 0.14 in)
Deflection limit---- 0.15 mm (0.006 in)1.0 mm (0.04 in)
Pad thickness6.4 mm (0.25 in)
Master cylinder inside dia.14.0 mm (0.551 in)----
Caliper cylinder inside dia.27.0 mm (1.063 in) · 1----
Brake fluid typeDOT #4----
Brake lever and brake pedal: Brake lever position82.5 mm (3.25 in)----
Brake pedal height(vertical height below footrest top)5 mm (0.20 in)----
Clutch lever free play (at lever pivot)2 ~ 4 mm (0.08 ~ 0.16 in)----
Throttle grip free play3 ~ 5 mm (0.12 ~ 0.20 in) ----

MAINTENANCE SPECIFICATIONS

YAMAHA WR400F (1999) - MAINTENANCE SPECIFICATIONS - 1

Part to be tightened Thread size Q'tyTightening torque
Nm m·kg ft·lb
Handle crown and outer tube M8 · 1.25 4 23 23 17
Under bracket and outer tube M8 · 1.25 4 20 20 14
Handle crown and steering shaft M24 · 1.0 1 145 14.5 105
Handlebar holder (upper) M8 · 1.25 4 23 2.3 17
Steering ring nutM28 · 1.01Refer to NOTE.
Front fork and cap boltM48 · 1.0 230 3.0 22
Front fork and base valveM30 · 1.0 255 5.5 40
Cap bolt and damper rod (front fork)M12 · 1.252292.921
Bleed screw (front fork) and cap boltM5 · 0.8210.10.7
Front fork and protectorM6 · 1.06101.07.2
Front fork and brake hose holderM6 · 1.02101.07.2
Front fork and hose coverM8 · 1.251161.611
Front fork and hose coverM6 · 1.0170.75.1
Throttle cable capM5 · 0.8240.42.9
Clutch lever holderM5 · 0.8240.42.9
Decompression lever holderM5 · 0.8240.42.9
Front brake master cylinder and bracketM6 · 1.0290.96.5
Front brake master cylinder capM4 · 0.7220.21.4
Brake lever mounting (bolt)M6 · 1.0170.75.1
Brake lever mounting (nut)M6 · 1.0170.75.1
Brake lever position locknutM6 · 1.0270.75.1
Cable guide (front brake hose) and guide stayM5 · 0.8140.42.9
Front brake hose union bolt (master cylinder)M10 · 1.251303.022
Front brake hose union bolt (caliper)M10 · 1.251303.022
Front brake caliper and front forkM8 · 1.25 223 2.3 17
Brake caliper (front and rear) and pad pin M101.0 1 18 1.813
Brake caliper (front and rear) and pad pin plugM10 · 1.0130.32.2
Brake caliper (front and rear) and bleed screwM8 · 1.25160.64.3
Front wheel axle and nutM16 · 1.5110510.575
Front wheel axle holderM8 · 1.25 423 2.3 17
Front brake disc and wheel hubM6 · 1.06121.28.7
Rear brake disc and wheel hubM6 · 1.06141.410
Brake pedal mountingM8 · 1.25 119 1.9 13
Rear brake master cylinder and frameM6 · 1.02101.07.2

NOTE:

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

MAINTENANCE SPECIFICATIONS

YAMAHA WR400F (1999) - MAINTENANCE SPECIFICATIONS - 1

Part to be tightened Thread size Q'tyTightening torque
Nm m·kg ft·lb
Rear brake reservoir tank and frame M6 · 1.010 1.0 7.2
Rear brake hose union bolt (caliper) M10 · 1.251 30 3.0 22
Rear brake hose union bolt (master cylinder) M101.25 1 303.0 22
Rear wheel axle and nutM20 · 1.5112512.590
Driven sprocket and wheel hubM8 · 1.25 642 4.2 30
Nipple (spoke)-72 30.32.2
Disc cover and rear brake caliperM6 · 1.0270.75.1
Protector and rear brake caliperM6 · 1.0270.75.1
Engine mounting:
Engine bracket and frameM8 · 1.25 734 3.4 24
Engine and frame (front)M10 · 1.25 169 6.9 50
Engine and frame (upper)M10 · 1.25 155 5.5 40
Engine and frame (lower)M10 · 1.25 169 6.9 50
Pivot shaft and nutM16 · 1.5 185 8.5 61
Relay arm and swingarmM14 · 1.5 180 8.0 58
Relay arm and connecting rodM14 · 1.5 180 8.0 58
Connecting rod and frameM14 · 1.5 180 8.0 58
Rear shock absorber and frameM10 · 1.25 156 5.6 40
Rear shock absorber and relay armM10 · 1.25 153 5.3 38
Rear frame and frameM8 · 1.25 326 2.6 19
Swingarm and brake hose holderM5 · -440.42.9
Drive chain tensioner mountingM8 · 1.252191.913
Chain support and swingarmM6 · 1.0370.75.1
Seal guard and swingarmM5 · 0.8440.42.9
Fuel tank mountingM6 · 1.0 210 1.0 7.2
Fuel tank and fuel cockM6 · 1.0270.75.1
Fuel tank and seat set bracketM6 · 1.0170.75.1
Fuel tank and hooking screw (fitting band)M6 · 1.0170.75.1
Fuel tank and fuel tank bracketM6 · 1.0470.75.1
Seat mountingM8 · 1.25 223 2.3 17
Side cover mountingM6 · 1.0270.75.1
Air scoop mounting (For USA, CDN)M6 · 1.0640.42.9
Air scoop and fuel tankM6 · 1.0 4440.4 2.9
(For EUROPE, AUS, NZ, ZA)
Air scoop and radiator panel (lower)M6 · 1.0 2440.4 2.9
(For EUROPE, AUS, NZ, ZA)
Rear fender mountingM6 · 1.0470.75.1
Number plateM6 · 1.0370.75.1
Coolant reservoir tankM6 · 1.0270.75.1

NOTE:

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

EG212300
ELECTRICAL

Item Standard Limit
Ignition system: Advancer type Electrical ---
C.D.I.: Magneto-model/manufacturer F5BF/YAMAHA Source coil 1 resistance (color) 640 ~ 960 Ω at---- 20 °C (68 °F) (Green - Brown)----
Source coil 2 resistance (color) 464 ~ 696 Ω at20 °C (68 °F) (Green - Pink)----
Lighting coil resistance (color) 0.16 ~ 0.24 Ω at20 °C (68 °F) (Black - Yellow)
Pickup coil resistance (color) 248 ~ 372 Ω at20 °C (68 °F) (White - Red)----
CDI unit-model/manufacturer 5GS/YAMAHA ---
Ignition coil: Model/manufacturer JF2/YAMAHA ---
Minimum spark gap6 mm (0.24 in)----
Primary winding resistance0.20 ~ 0.30 Ω at 20 °C (68 °F)----
Secondary winding 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
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 SPECIFICA- TION
Nm m·kg ft·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 WR400F (1999) - GENERAL TORQUE SPECIFICATIONS - 1

A: Distance between flats
B: Outside thread diameter

EC230000

DEFINITION OF UNITS

Unit ReadDefinition Measure
mmmillimeter10-3meterLength
cmcentimeter102meterLength
kg kilogram 103gram Weight
N Newton 1 kg·m/sec2Force
NmNewton meterN·mTorque
m·kgMeter kilogramm·kgTorque
Pa Pascal N/m2Pressure
N/mm Newton per millimeter N/mm Spring rate
LLiterVolume or capacity
cm3Cubic centimeterVolume or capacity
r/min Revolutionper minute—Engine speed

CHARACTERISTIQUES

CHARACTERISTIQUES GENERALES

LUBRICATION DIAGRAMS

① Oil delivery pipe
② Intake camshaft
③ Exhaust camshaft
④ Oil filter
⑤ Oil pump
⑥ Main axle
⑦ Drive axle

YAMAHA WR400F (1999) - LUBRICATION DIAGRAMS - 1

SCHEMAS DE GRAISSAGE

① Camshaft
② Connecting rod
③ Oil filter
④ Crankshaft
⑤ Main axle
⑥ Drive axle
⑦ Oil delivery pipe

YAMAHA WR400F (1999) - SCHEMAS DE GRAISSAGE - 1

① Hose guide
② Brake hose
③ Regulator
④ Fuel tank breather hose
⑤ Oil tank breather hose
⑥ Clamp
⑦“ENGINE STOP” button lead
Sub wire harness
⑨ Tail light lead
10 TPS (throttle position sensor) lead
① Neutral switch lead
⑫ Oil hose
⑬ Cylinder head breather hose
CDI magneto lead
15 Hose holder
16 Clutch cable
17 Decompression cable
18 Lights switch lead
19 Carburetor breather hose
20 Overflow hose
② Coolant reservoir tank breather hose

Pass the fuel tank breather hose behind handlebar, then insert it into the steering shaft hole.
Pass the decompression cable, "ENGINE STOP" button lead and lights switch lead under where the oil hose is attached.
Pass the "ENGINE STOP" button lead, regulator lead and lights switch lead along the inner and side of the decompression cable.
Fasten the CDI magneto lead, neutral switch lead "ENGINE STOP" button lead and lights switch lead to the frame with a plastic locking tie.

Pass the "ENGINE STOP" button lead and lights switch lead along the inner side of the oil tank breather hose.
Fasten the sub wire harness, "ENGINE STOP" button lead and lights switch lead to the frame with a plastic locking tie.
Pass the cylinder head breather hose along the right side of the oil tank breather hose.
Fasten the sub wire harness to the frame with a plastic locking tie and cut off the tie end.
Fasten the TPS lead (in the sub wire harness) under the frame.

YAMAHA WR400F (1999) - SCHEMAS DE GRAISSAGE - 2

CHEMINEMENT DES

CABLES

Fasten the TPS lead under the coupler to the frame with a plastic locking tie.
Pass the carburetor breather hose and overflow hose between the connecting rod and cross tube (frame).
Fasten the neutral switch lead and oil hose together with a plastic locking tie.
M Fasten the neutral switch lead to the frame with a plastic band.
N Fasten the cylinder head breather hose with the hose holder.
Fasten the neutral switch lead and CDI magneto lead together with a plastic band.
Pass the clutch cable through the cable guide.

Pass the cylinder head breather hose along the inner side of the radiator pipe.
Pass the clutch cable between the frame and radiator and over the lower boss on the radiator.
Pass the neutral switch lead and CDI magneto lead over the middle radiator mounting boss. Then, pass the decompression cable under the middle radiator mounting boss and along the left side of the neutral switch lead and CDI magneto lead.
Pass the clutch cable through the cable guide.
Fit the brake hose into the guide on the protector.

Fasten the ignition coil lead (in the sub wire harness) on the upper inside of the frame and cut off the tie end.
Pass the ignition coil lead (in the sub wire harness) under the cushion bracket (frame).
Fasten the ignition coil lead (in the sub wire harness) to the frame with a plastic locking tie and cut off the tie end.
Pass the carburetor breather hoses and overflow hose so that all there hoses do not contact the rear shock absorber.

YAMAHA WR400F (1999) - CABLES - 1

① Coolant reservoir tank breather hose
② Clamp
③ Ignition coil
④ High tension cord
⑤ CDI unit
⑥ CDI unit band
⑦ Radiator (left)
⑥ Radiator (right)
⑨ Decompression cable
CDI unit stay (frame)

A Fasten the coolant reservoir tank breather hose and carburetor breather hose together with a plastic locking tie.
Fasten the ignition coil lead to the frame with a plastic band.
Pass the ignition coil lead (in the sub wire harness) so that it does not contact the carburetor and rear shock absorber and connect it with the lead from the ignition coil on the inside of the frame.
Fasten the ignition coil and ground lead to the frame with the bolt.
Pass the throttle cables over the high tension cord.

Pass the throttle cables along the outer side of the CDI unit leads.
6 Fasten the CDI unit leads to the frame with a plastic locking tie.
Fit the boot over the coupler.
Pass the throttle cables between the top radiator mounting boss and middle radiator mounting boss.
Pass the CDI unit leads over the top radiator mounting boss.
K Cross the pull and return throttle cables before the radiator.
Pass the throttle cables through cable guide.
Insert the CDI unit band over the CDI unit stay (frame) as far as possible.

YAMAHA WR400F (1999) - CABLES - 2

A Fasten the "ENGINE STOP" button lead to the handlebar with the plastic band.
Pass the decompression cable between the brake hose and clutch cable.
Pass the throttle cables between the handle crown and trip meter.
Pass the light switch leads behind the "ENGINE STOP" button lead, then pass the head light lead (of the light switch leads) in front of the head pipe.
E Install the trip meter cable so that its bent portion faces the chassis rear.
F Install the brake hose so that it contacts the master cylinder projection and that its bent portion faces downward.

YAMAHA WR400F (1999) - CABLES - 3

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.

ItemAfter break-inEvery raceEvery third (or 500 km)Every fifth (or 1,000 km)As requiredRemarks
ENGINE OIL Replace
OIL FILTER Replace
VALVES Check the valve clearances.The engine must be cold. Check the valve seats and valve stems for wear.
Inspect Replace
VALVE SPRINGSCheck the free length and the tilt.
Inspect Replace
VALVE LIFTERSCheck for scratches and wear.
Inspect Replace
CAMSHAFTSInspect the camshaft surface.
Inspect Replace
CAMSHAFT SPROCKETSCheck for wear on the teeth and for damage.
Inspect Replace
PISTONInspect crack Remove carbon
Inspect Clean Replace
PISTON RINGCheck ring end gap
Inspect Replace
PISTON PIN
Inspect Replace
CYLINDER HEADRemove carbon Change gasket
Inspect and clean
CYLINDERInspect score marks Inspect wear
Inspect and clean Replace
CLUTCH
Inspect and adjust ReplaceInspect housing, friction plate, clutch plate and spring
TRANSMISSION
Inspect Replace bearing

YAMAHA WR400F (1999) - CABLES - 4

ItemAfter break-inEvery raceEvery third (or 500 km)Every fifth (or 1,000 km)As requiredRemarks
SHIFT FORK, SHIFT CAM, GUIDE BAR InspectInspect wear
ROTOR NUT Retighten
MUFFLER Inspect Clean Replace Retighten*Whichever comes first
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 Replace 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
OIL STRainer (frame) Clean
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 sealSuspension oil "01"

MAINTENANCE INTERVALS

INSP ADJ

YAMAHA WR400F (1999) - MAINTENANCE INTERVALS - 1

ItemAfter break-inEvery raceEvery third (or 500 km)Every fifth (or 1,000 km)As requiredRemarks
FRONT FORK OIL SEAL AND DUST SEAL Clean and lubeLithium base grease
REAR SHOCK ABSORBER Inspect and adjust Lube and retightenLithium base grease
CHAIN GUARD AND ROLLERS Inspect
SWINGARM Inspect and retighten
RELAY ARM, CONNECTING ROD Inspect and lubeLithium base grease
STEERING HEAD Inspect free play and retighten Clean and lube Replace bearingLithium base grease
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 connection LubricateYamaha cable lube or SAE 10W-30 motor oil

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

Item Routine Page
CoolantCheck that coolant is filled up to the radiator filler cap. Check that the coolant level is correct in the coolant reservoir tank. 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.1-12
Engine oilCheck that the oil level is correct. Check the crankcase and frame oil line for leakage.P.3-13 ~ 17
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
Brakes Check the play of front brake and effect of front and rear brake. P.3-25 ~ 31
ChainCheck chain slack and alignment. Check that the chain is lubricated properly.P.3-32 ~ 34
WheelsCheck for excessive wear and tire pressure. Check for loose spokes and have no excessive play.P.3-42 ~ 43
SteeringCheck that the handlebar can be turned smoothly and have no excessive play.P.3-43 ~ 44
Front forks and rear shock absorberCheck that they operate smoothly and there is no oil leakage. P.3-34 ~ 41
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.
Muffler Check that the muffler is tightly mounted and has no cracks. P.4-2
Sprocket Check that the driven sprocket tightening bolt is not loose. P.3-32
Lubrication Check for smooth operation. Lubricate if necessary. P.3-45
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-17
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are connected tightly.P.1-5
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 ~ 21

CONTROLE ET ENTRETIEN AVANT UTILISATION

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:

Coolant level

Coolant level should be between the maximum ⑧ and minimum ⑤ marks.

Coolant level is below the "LOW" level line Add soft water (tap water) up to the proper level.

  1. Start the engine and let it warm up for several minutes.
  2. Turn off the engine and check the coolant level again.

NOTE:

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

EC353011

COOLANT REPLACEMENT

WARNING

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

MOTEUR

CONTROLE DU NIVEAU DU LIQUIDE DE REFROIDISSEMENT

A VERTISSEMENT

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:

Seat

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:

Engine guard ①
Coolant drain bolt ②

  1. Remove:

  2. 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

10Nm(1.0m·kg,7.2ft·lb)

Engine guard

  1. Fill:

. Radiator
. Engine

To specified level.

YAMAHA WR400F (1999) - A VERTISSEMENT - 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: 1.2 L (1.06 Imp qt, 1.27 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 WR400F (1999) - WARNING - 1

YAMAHA WR400F (1999) - WARNING - 2

10.Install:

  • Radiator cap

11.Fill:

Coolant reservoir tank

Midway ⑥ between maximum and minimum marks on the tank.

12.Install:
Coolant reservoir cap
13.Start the engine and let it warm up for several minutes.
14. 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.

EC355000

RADIATOR CAP INSPECTION

  1. Inspect:

  2. Seal (radiator cap) ①

  3. Valve and valve seat ②

Crack/damage Replace.

Furdeposits ③ Cleanor replace.

ATTENTION:

  1. Attach:

  2. Radiator cap tester ① and adapter ②

YAMAHA WR400F (1999) - ATTENTION: - 1

Radiator cap tester: YU-24460-1/90890-01325

Adapter: YU-33984/90890-01352

NOTE:

Apply water on the radiator cap seal.

③ Radiator cap

  1. Apply the specified pressure.

YAMAHA WR400F (1999) - NOTE: - 1

Radiator cap opening pressure: 110 kPa (1.1 kg/cm², 15.6 psi)

  1. Inspect:

Pressure

Impossible to maintain the specified pressure for 10 seconds Replace.

YAMAHA WR400F (1999) - NOTE: - 2

EC357002

COOLING SYSTEM INSPECTION

  1. Inspect:
    Coolant level
  2. Attach:
  3. Radiator cap tester ① and adapter ②

YAMAHA WR400F (1999) - COOLING SYSTEM INSPECTION - 1

Radiator cap tester: YU-24460-1/90890-01325

Adapter: YU-33984/90890-01352

  1. Apply the specified pressure.

YAMAHA WR400F (1999) - COOLING SYSTEM INSPECTION - 2

Standard pressure: 180 kPa (1.8 kg/cm², 25.6 psi)

CONTROLE DE LA PRESSION D'OUVERTURE DU BOUCHON DU RADIATEUR

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

4. Inspect:

Pressure

Impossible to maintain the specified pressure for 10 seconds Repair.
Radiator
- Radiator hose joint

Coolant leakage Repair or replace.

  • Radiator hose
    Swelling Replace.

EC359001

CLUTCH ADJUSTMENT

  1. Check:

  2. Clutch lever free play @
    Out of specification Adjust.

YAMAHA WR400F (1999) - CLUTCH ADJUSTMENT - 1

Clutch lever free play a: 2 4 mm (0.08 0.16 in)

2. Adjust:

  • Clutch lever free play

Clutch lever free play adjustment steps:

Loosen the locknut ①.
- Turn the adjuster ② until free play 已 is within the specified limits.
- Tighten the locknut.

NOTE:

Make minute adjustment on the lever side using the adjuster ③.
After adjustment, check proper operation of clutch lever.

N.B.:

THROTTLE CABLE ADJUSTMENT

  1. Check:

Throttle grip free play @

Out of specification Adjust.

YAMAHA WR400F (1999) - THROTTLE CABLE ADJUSTMENT - 1

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

  1. Adjust:

Throttle grip free play

Throttle grip free play adjustment steps:

  • Remove the throttle cable cover ①.

NOTE:

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

1st step:

  • Loosen the locknut ④ on throttle cable #2.
  • Turn the adjuster ⑤ in or out to take up any slack on throttle cable #2.

2nd step:

Loosen the locknut ⑥ on throttle cable #1.
- Turn the adjuster ⑦ in or out until the specified free play is obtained.

Turning in: Free play is increased.

Turning out:

Free play is decreased.

  • Tighten the locknuts.

YAMAHA WR400F (1999) - Turning in: Free play is increased. - 1

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.

EC35S002

THROTTLE LUBRICATION

  1. Remove:

Rubber cover ①
- Throttle cable cap ②

REGLAGE DES CABLES D'ACCE- LERATION

Lithium soap base grease On the throttle cable end a.

  1. Install:

Throttle cable cap

DECOMPRESSION LEVER ADJUSTMENT

  1. Check:

Decompression lever free play

Checking steps:

  • Remove the timing plug.
  • Turn the crankshaft counterclockwise to align the T.D.C. mark ⑧ on the rotor with the align mark ⑥ on the crankcase cover when piston is at T.D.C. on compression stroke.
  • Check the free play ⑥

YAMAHA WR400F (1999) - Checking steps: - 1

Free play: 5 9mm (0.20 0.35 in)

  1. 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 handlebars are turned fully both ways. If the decompression cable is too tense, the engine will stop by the decompression system.

EC35G040

AIR FILTER CLEANING

NOTE:

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

REGLAGE DU LEVIER DE DECOMPRESSION/NETTOYAGE DU FILTRE A AIR EINSTELLUNG DES DEKOMPRESSIONSHEBELS/LUFTFILTER REINIGEN AJUSTE DE LA PALANCA DE DESCOMPRESION/LIMPIEZA DEL FILTRO DE AIRE

INSP ADJ

YAMAHA WR400F (1999) - INSP ADJ - 1

2. Appliquer:

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.

  1. Remove:

Seat

  1. Disconnect:

Tail light lead connectors ①

  1. Remove:

Air filter case cover ②

  1. Remove:

Fitting bolt ①
.Washer ②
Air filter element ③
Filter guide ④

  1. 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.

  1. Inspect:

Air filter element

Damage Replace.

  1. Apply:

Foam-air-filter oil or engine mixing oil To the element.

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

  1. Install:

Filter guide ①

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

ATTENTION:

Lithium soap base grease

On the matching surface @ on air filter element.

10.Install:

Air filter element ①
.Washer
Fitting bolt

2Nm(0.2m·kg,1.4ft·lb)

NOTE:

Align the projection 当 on filter guide with the hole ⑥ in air filter case.

ENGINE OIL LEVEL INSPECTION

  1. Stand the motorcycle on a level surface.

NOTE:

  • When checking the oil level make sure that the motorcycle is upright.
  • Place the motorcycle on a suitable stand.

WARNING

Never remove the oil tank cap just after high speed operation. The heated oil could spurt out, causing danger. Wait until the oil cools down to approximately 70^ (158 F).

  1. Idle the engine more than 3 minutes while keeping the motorcycle upright. Then stop the engine and inspect the oil level.
  2. Remove:
    Oil tank cap ①

YAMAHA WR400F (1999) - WARNING - 1

CONTROLE DUNIVENUEAU DHUILE MOTEUR MOTOROLSTAND KONTROLLIEREN INSPECCION DEL NIVEL DE ACEITE DE MOTOR

9.Appliquer:

Graisse a base de savon an lithium

Oil level should be between maximum

@ and minimum 包 marks.

Oil level low Add oil to proper level.

NOTE:

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

Insert the gauge lightly.

(For USA and CDN)

YAMAHA WR400F (1999) - (For USA and CDN) - 1

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.

(Except for USA and CDN)

YAMAHA WR400F (1999) - (Except for USA and CDN) - 1

Refer to the following chart for the selection of oils which are suited to the atmospheric temperatures.

Recommended engine oil classification:

API STANDARD:

API "SH" or higher grade (Designed primarily for motorcycles)

YAMAHA WR400F (1999) - API STANDARD: - 1

YAMAHA WR400F (1999) - API STANDARD: - 2

CAUTION:

. Do not add any chemical additives or use oils with a grade of CD ⑧ or higher.
- Do not use oils labeled "ENERGY CONSERVING II" ⑥ or higher. Engine oil also lubricates the clutch and additives could cause clutch slippage.
. Do not allow foreign materials to enter the crankcase.

CONTROLE DUNIVENUEAU DHUILE MOTEUR MOTOROLSTAND KONTROLLIEREN INSPECCION DEL NIVEL DE ACEITE DE MOTOR

  1. Controller:
  1. Start the engine and let it warm up for several minutes.

CAUTION:

When the oil tank is empty, never start the engine.

  1. Idle the engine more than 10 seconds while keeping the motorcycle upright. Then stop the engine and add the oil to the maximum level.

  2. Install:

Oil tank cap

YAMAHA WR400F (1999) - CAUTION: - 1

YAMAHA WR400F (1999) - CAUTION: - 2

YAMAHA WR400F (1999) - CAUTION: - 3

ENGINE OIL REPLACEMENT

  1. Start the engine and let it warm up for several minutes.
  2. Stop the engine and place an oil pan under the drain bolt.

  3. Remove:

. Oil filler plug ①
- Drain bolt (with gasket) ②
- Drain bolt (with gasket) ③
- Oil filter drain bolt (O-ring) ④

Drain the crankcase and oil tank (frame) of its oil.

  1. Remove:

Engine skidplate
Engine oil hose clamp ①
Engine oil hose ②
. Oil strainer (frame) ③

  1. Clean:

Oil strainer (frame)

  1. If the oil filter is to be replaced during this oil change, remove the following parts and reinstall them.

Replacement steps:

  • Remove the exhaust pipe.
  • Remove the oil filter 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 cover.

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

YAMAHA WR400F (1999) - Replacement steps: - 1

  1. Install:

  2. Oil strainer (frame) ①

90Nm(9.0m·kg,65ft·lb)

Plain washer ② New
Engine oil hose ③
Engine oil hose clamp ④
Engine skid plate

  1. Install:

Gaskets
New
Oil filter drain bolt
10Nm(1.0m·kg,7.2ft·lb)
- Drain bolt (crankcase)
20Nm(2.0m·kg,14ft·lb)
- Drain bolt (frame)
23Nm(2.3m·kg,17ft·lb)

  1. Fill:

Oil tank (frame)

YAMAHA WR400F (1999) - Replacement steps: - 2

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)

ENGINE OIL REPLACEMENT/ PILOT SCREW ADJUSTMENT

INSP ADJ

YAMAHA WR400F (1999) - ENGINE OIL REPLACEMENT/ PILOT SCREW ADJUSTMENT - 1

10.Install:

Oil filler plug

11.Inspect:

Engine (for oil leaks)
. Oil level

Refer to "ENGINE OIL LEVEL INSPECTION".

YAMAHA WR400F (1999) - ENGINE OIL REPLACEMENT/ PILOT SCREW ADJUSTMENT - 2

  1. Check:

Oil pressure

Checking steps:

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

YAMAHA WR400F (1999) - Checking steps: - 1

Oil gallery bolt: 18 Nm (1.8 m·kg, 13 ft·lb)

PILOT SCREW ADJUSTMENT

  1. Adjust:

Pilot screw ①

YAMAHA WR400F (1999) - PILOT SCREW ADJUSTMENT - 1

Adjusting 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 WR400F (1999) - NOTE: - 1

Pilot screw:

1-5/8 turns out

  • 1-1/2 turns out
    (for reference only)

  • Except for USA

IDLE SPEED ADJUSTMENT/ VALVE CLEARANCE ADJUSTMENT

YAMAHA WR400F (1999) - IDLE SPEED ADJUSTMENT/ VALVE CLEARANCE ADJUSTMENT - 1

EC35M021

IDLE SPEED ADJUSTMENT

  1. Start the engine and thoroughly warm it up.
  2. Adjust:

Idle 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 ⑧

To decrease idle speed

Turn the throttle stop screw ① out 包

YAMAHA WR400F (1999) - Adjustment steps: - 1

Engine idling speed: 1,700 ~ 1,900 r/min

VALVE CLEARANCE 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
Side covers
Air scoops
.Fuel tank

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

  1. Drain:

Coolant

Refer to "COOLANT REPLACEMENT" section.

  1. Remove:

RADIATOR
Refer to "RADIATOR" section in the CHAPTER 4.
Engine stay (upper)
Cylinder head breather hose
Cylinder head cover
- Spark plug cap

Refer to "CYLINDER HEAD COVER" section in the CHAPTER 4.

VALVE CLEARANCE ADJUSTMENT

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 1

  1. Remove:

  2. Timing plug ①
    . Straight plug ②
    O-ring

  3. Check:

  4. Valve clearance

Out of specification Adjust.

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 2

Valve clearance (cold):

Intake valve:

0.15 0.20mm (0.0059 0.0079 in)

Exhaust valve:

0.25 ~ 0.30 mm (0.0098 ~ 0.0118 in)

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 3

Checking steps:

  • Turn the crankshaft counterclockwise with a wrench.

NOTE:

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

  • Align the T.D.C. mark ⑧ on the rotor with the align mark ⑥ on the crankcase cover when piston is at T.D.C. on compression stroke.

NOTE:

TDC on compression stroke can be found when the cam lobes are opposite each other as shown.

Measure the valve clearance using a feeler gauge ①.

NOTE:

Record the measured reading if the clearance is incorrect.

YAMAHA WR400F (1999) - NOTE: - 1

YAMAHA WR400F (1999) - NOTE: - 2

  1. Déposser:

VALVE CLEARANCE ADJUSTMENT

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 1

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 2

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 3

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 4

YAMAHA WR400F (1999) - VALVE CLEARANCE ADJUSTMENT - 5

  1. Adjust:

  2. Valve clearance

Adjustment steps:

Loosen the timing chain tensioner cap bolt.
- Remove the timing chain tensioner and camshaft caps.

NOTE:

Remove the camshaft cap bolts in a crisscross pattern from the outside working inwards.

  • Remove the camshaft (intake ① and exhaust ②).

NOTE:

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

  • Remove the decompression cable ④ , guide ⑤ , bolt ⑥ and decompression shaft ⑦ .
  • Remove the valve lifters ⑧ and the pads ⑨

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. 1201.20 mmPads are available in 0.05 mm increments
~
No. 2402.40 mm

NOTE:

The thickness (号) of each pad is indicated in hundredths 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 or 2 0
5(NOT ROUNDED OFF)
810

EXAMPLE:

Installed pad number = 148

Rounded off value = 150

NOTE:

Pads can only be selected in 0.05mm increments.

  • 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 ⑩ and the valve lifters ⑪

NOTE:

  • Lubricate the valve lifters and pads with molybdenum disulfide oil.
  • Valve lifter must turn smoothly when rotated with a finger.
  • Be careful to reinstall valve lifters and pads in their original place.
    Install the camshafts (exhaust and intake), the timing chain and the camshaft caps.

YAMAHA WR400F (1999) - NOTE: - 1

Bolt (camshaft cap)

7 Nm (0.7m· kg,5.1ft· lb)

Install the timing chain tentioner.

Refer to "CAMSHAFTS" section in the CHAPTER 4.

NOTE:

Refer to "CAMSHAFTS" section in the CHAPTER 4.
- Turn the crankshaft counterclockwise several turns so that the installed parts settle into the right position.
- Recheck the valve clearance.
- If the clearance is still incorrect, repeat all the clearance adjustment steps until the specified clearance is obtained.

  1. Install:

All removed parts

NOTE:

Install all removed parts in reversed order of their removal. Note the following points.

Monter le tendeur de la chaine de distribution. Se reporter a la section "ARBRES A CAMES" du CHAPITRE 4.

N.B.:

  • 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 WR400F (1999) - N.B.: - 1

YAMAHA WR400F (1999) - N.B.: - 2

  1. Remove:

Bolt (spark arrester) ①

  1. Remove:

  2. Spark arrester ①

Pull the spark arrester out of the muffler.

  1. Clean:

  2. Spark arrester

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

  1. Install:

  2. Spark arrester

Insert the spark arrester into the muffler and align the bolt holes.

Bolt (spark arrester)

10Nm(1.0m·kg,7.2ft·lb)

NETTOYAGE DU PARE-ETINCELLES (pour les USA)

AVERTISSEMENT

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.

  1. Remove:

  2. Master cylinder cap
    Diaphragm

  3. Protector (rear brake)

  4. Bleed:

  5. Brake fluid

A Front
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 WR400F (1999) - 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 FAHRWERK/HYDRAULISCHE BREMSANLAGE ENTLUFTEN CHASIS/PURGA DEL AIRE DEL SISTEMA DE FRENOS

PARTIE CYCLE

PURGE DE L'AIR DU SYSTEME DE FREINAGE

A VERTISSEMENT

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
  • Master cylinder cap

YAMAHA WR400F (1999) - Install: - 1

YAMAHA WR400F (1999) - Install: - 2

EC362031

  • Brake lever position @

YAMAHA WR400F (1999) - EC362031 - 1

Standard brake lever position @: 82.5 mm (3.25 in)

2. Adjust:

  • Brake lever position

Loosen the locknuts ①, then adjust the lever position by changing their tightening position.

3. Tighten:

Locknut 7Nm (0.7 m·kg, 5.1 ft·lb)

CAUTION:

Be sure to tighten the locknuts, as it will cause poor brake performance.

REGLAGE DE FREIN AVANT VORDERRADBREMSE EINSTELLLEN AJUSTE DEL FRENO DELANTERO

INSP ADJ

YAMAHA WR400F (1999) - INSP ADJ - 1

N.B.:

  1. Check:

  2. Brake pedal height @

Out of specification Adjust.

YAMAHA WR400F (1999) - N.B.: - 1

Brake pedal height @: 5 mm (0.20 in)

  1. Adjust:

  2. Brake pedal height

Pedal height adjustment steps:

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

YAMAHA WR400F (1999) - Pedal height adjustment steps: - 1

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) ⑥ away from the brake pedal ⑤).
    After the pedal height adjustment, make sure that the rear brake does not drag.

EC365080

FRONT BRAKE PAD INSPECTION AND REPLACEMENT

  1. Inspect:

  2. Brake pad thickness @

Out of specification Replace as a set.

YAMAHA WR400F (1999) - FRONT BRAKE PAD INSPECTION AND REPLACEMENT - 1

Brake pad thickness @:

Standard

4.4 mm (0.17 in) 1.0 mm (0.04 in)

  1. Replace:

  2. Brake pad

Brake pad replacement steps:

  • Remove the pad pin plug ①.

REGLAGE DU FREIN ARRIERE

  1. Contoler:

Loosen the pad pin ②.
- Remove the brake hose holder ③ and 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 caliper piston in.

CAUTION:

Do not reuse the drained brake fluid.

  • Tighten the bleed screw.

YAMAHA WR400F (1999) - CAUTION: - 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 caliper recesses b.
- Temporarily tighten the pad pin at this point.
Install the brake hose holder ⑨ and caliper ⑩ and tighten the pad pin ⑪

NOTE:

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

YAMAHA WR400F (1999) - NOTE: - 1

Bolt (caliper):

23 Nm (2.3 m·kg, 17 ft·lb)

Pad pin:

18 Nm (1.8 m·kg, 13 ft·lb)

CONTROLE ET CHANGESMENT DES PLAQUETTES DE FREIN AVANT VORDERRAD-BREMSBELAGE KONTROLLIEREN UND ERNEUERN INSPECCION Y SUSTITUCION DE LAS PASTILLAS DEL FRENO DELANTERO

INSP ADJ

YAMAHA WR400F (1999) - INSP ADJ - 1

Install the pad pin plug ⑫.

YAMAHA WR400F (1999) - INSP ADJ - 2

3 Nm (0.3 m·kg, 2.2 ft·lb)

  1. Inspect:

  2. Brake fluid level

Refer to "BRAKE FLUID LEVEL INSPECTION" section.

  1. Check:

  2. Brake lever operation

A soft or spongy feeling Bleed brake system.

Refer to "BRAKE SYSTEM AIR BLEEDING" section.

YAMAHA WR400F (1999) - INSP ADJ - 3

EC366060

REAR BRAKE PAD INSPECTION AND REPLACEMENT

  1. Inspect:

  2. Brake pad thickness @

Out of specification Replace as a set.

YAMAHA WR400F (1999) - REAR BRAKE PAD INSPECTION AND REPLACEMENT - 1

YAMAHA WR400F (1999) - REAR BRAKE PAD INSPECTION AND REPLACEMENT - 2

Brake pad thickness @:

Standard

6.4 mm (0.25 in) 1.0 mm (0.04 in)

  1. Replace:

  2. 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 caliper ⑤ . Refer to "FRONT WHEEL AND REAR WHEEL" section in the CHAPTER 5.

YAMAHA WR400F (1999) - Brake pad replacement steps: - 1

CONTROLE ET CHANGESMENT DES PLAQUETTES DE FREIN AVANT HINTERRAD-BREMSBELAGE KONTROLLIEREN UND ERNEUERN INSPECCION Y SUSTITUCION DE LA PASTILLA DEL FRENO TRASERO

  • 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 caliper piston in.

CAUTION:

Do not reuse the drained brake fluid.

  • Tighten the bleed screw.

YAMAHA WR400F (1999) - CAUTION: - 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 包 into the caliper recesses 包 .
- Temporarily tighten the pad pin at this point.
Install the caliper ⑫ and rear wheel ⑬ . Refer to "FRONT WHEEL AND REAR WHEEL" section in the CHAPTER 5.
- Tighten the pad pin ⑭.

YAMAHA WR400F (1999) - NOTE: - 1

Pad pin: 18 Nm (1.8 m·kg, 13 ft·lb)

Install the pad pin plug 15 and protector 16.

YAMAHA WR400F (1999) - NOTE: - 2

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

  1. Inspect:

  2. Brake fluid level

Refer to "BRAKE FLUID LEVEL

INSPECTION" section.

  1. Check:

  2. Brake pedal operation

A soft or spongy feeling Bleed brake system.

Refer to "BRAKE SYSTEM AIR

BLEEDING" section.

EC36b000

REAR BRAKE PAD INSULATOR

INSPECTION

  1. Remove:

  2. Brake pad

Refer to "REAR BRAKE PAD INSPEC

TION AND REPLACEMENT" section.

  1. Inspect:

Rear brake pad insulator ①

Damage Replace.

EC367001

  1. Place the master cylinder so that its top is in a horizontal position.

  2. Inspect:

  3. Brake fluid level

Fluid at lower level Fill up.

@ Lower level

A Front

Rear

YAMAHA WR400F (1999) - INSPECTION - 1

Recommended brake fluid:

DOT#4

YAMAHA WR400F (1999) - INSPECTION - 2

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.

Excessive wear Replace.

NOTE: Replace the drive, driven sprockets and drive chain as a set.

EC369002

DRIVE CHAIN INSPECTION

  1. Remove:

  2. Master link clip
    .Joint ①
    -O-rings ②

  3. Drive chain ③

  4. Clean:

  5. Drive chain

Place it in kerosene, and brush off as much dirt as possible. Then remove the chain from the kerosene and dry the chain.

  1. Measure:

  2. Drive chain length (10 links) @

Out of specification Replace.

YAMAHA WR400F (1999) - DRIVE CHAIN INSPECTION - 1

Drive chain length (10 links): Limit: 150.1 mm (5.91 in)

  1. Check:

  2. Drive chain stiffness

Clean and oil the chain and hold as illustrated.

Stiff Replace drive chain.

CONTROLE DES PIGNONS

  1. Contrôler:

Dent de pignon @

Usure excessive Changer.

N.B.:

Be sure to install the master link clip to the direction as shown.

Turning direction

  1. Lubricate:

  2. Drive chain

YAMAHA WR400F (1999) - CONTROLE DES PIGNONS - 1

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

YAMAHA WR400F (1999) - CONTROLE DES PIGNONS - 2

EC36A060

DRIVE CHAIN SLACK ADJUSTMENT

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

  3. Drive chain slack @

Above the seal guard installation bolt.

Out of specification Adjust.

YAMAHA WR400F (1999) - 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 chain slack with rear wheel in this "tight chain" position.

REGLAGE DE LA FLECHE DE CHAINE DE TRANSMISSION ANTRIEBSKETTEN-DURCHHANG EINSTELLLEN INSPECCION DE LA CADENA DE TRANSMISION

INSP ADJ

YAMAHA WR400F (1999) - INSP ADJ - 1

5. Monter:

  • Chaine de transmission ①
    Raccord ②
    Agrafe de I'attache rapide

New

ATTENTION:

Drive chain slack adjustment steps:

Loosen the axle nut ① and locknuts ②.
- Adjust chain slack by turning the adjusters ③.

To tighten Turn adjuster ③ counterclockwise.

To loosen Turn adjuster ③ clockwise and push wheel forward.

  • Turn each adjuster exactly the same amount to maintain correct axle alignment. (There are marks @ on each side of chain puller alignment.)

NOTE:

Turn the adjuster so that the chain is in line with the sprocket, as viewed from the rear.

CAUTION:

Too small 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 WR400F (1999) - Too small chain slack will overload the engine and other vital parts; keep the slack within the specified limits. - 1

Axlenut:

125 Nm (12.5 m·kg, 90 ft·lb)

  • Tighten the locknuts.

YAMAHA WR400F (1999) - Too small chain slack will overload the engine and other vital parts; keep the slack within the specified limits. - 2

EC36C000

FRONT FORK INSPECTION

  1. Inspect:

  2. Front fork smooth action

  3. Operate the front brake and stroke the front fork.
  4. Unsmooth action/oil leakage Repair or replace.

3. Régler:

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.

  1. Clean:

.Dust seal@
Oil seal ⑥

NOTE:

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

EC36H002

FRONT FORK REBOUND DAMPING FORCE ADJUSTMENT

  1. Adjust:

Rebound damping force

By turning the adjuster ①.

Stiffer 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:
Maximum Minimum
Fully turned in position20 clicks out (from maximum position)

NETTOYAGE DE BAGUE D'ETANCHEITE ET DE JOINT ANTIPOUSSE DE FOURCHE AVANT

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

YAMAHA WR400F (1999) - NETTOYAGE DE BAGUE D'ETANCHEITE ET DE JOINT ANTIPOUSSE DE FOURCHE AVANT - 1

Standard position:

8 clicks out

*14 clicks out

  • For EUROPE

CAUTION:

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

YAMAHA WR400F (1999) - CAUTION: - 1

WARNING

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

EC36J001

FRONT FORK COMPRESSION DAMPING FORCE ADJUSTMENT

  1. Remove:

Rubber cap

  1. Adjust:

  2. Compression damping force

By turning the adjuster ①.

Stiffer Increase the compression

damping force. (Turn the

adjuster ① in.)

Softer 6 Decrease the compression

damping force. (Turn the

adjuster ① out.)

YAMAHA WR400F (1999) - FRONT FORK COMPRESSION DAMPING FORCE ADJUSTMENT - 1

Extent of adjustment:

Maximum Minimum

Fully turned in position

20 clicks out (from maximum position)

-POSITION STANDARD:

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

YAMAHA WR400F (1999) - Maximum Minimum - 1

Standard position:

7 clicks out

*12 clicks out

  • For EUROPE

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

YAMAHA WR400F (1999) - WARNING - 1

EC36K000

REAR SHOCK ABSORBER INSPECTION

  1. Inspect:

  2. Swingarm smooth action

Abnormal noise/unsmooth action Grease the pivoting points or repair the pivoting points.

Damage/oil leakage Replace.

CONTROLE DE L'AMORTISSEUR ARRIREF EDERBEIN KONTROLLIEREN INSPECCION DEL AMORTIGUADOR TRASERO

INSP ADJ

YAMAHA WR400F (1999) - CONTROLE DE L'AMORTISSEUR ARRIREF EDERBEIN KONTROLLIEREN INSPECCION DEL AMORTIGUADOR TRASERO - 1

-POSITION STANDARD:

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

Rear frame

  1. Loosen:

Locknut ①

  1. Adjust:

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) @:
Standard length Extent of adjustment
245 mm (9.65 in) *244 mm (9.61 in)242 ~ 260 mm (9.53 ~ 10.24 in)
  • For EUROPE

NOTE:

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

CAUTION:

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

  1. Tighten:
    Locknut
  2. Install:
    Rear frame

REGLAGE DE LA PRECONTRAINTE DE RESSORT DE L'AMORTISSEUR ARRIERE

  1. Adjust:

  2. Rebound damping force By turning the adjuster ①.

YAMAHA WR400F (1999) - REGLAGE DE LA PRECONTRAINTE DE RESSORT DE L'AMORTISSEUR ARRIERE - 1

Stiffer a → Increase the rebound damp- ing force. (Turn the adjuster ① in.)
Softer b → Decrease the rebound damp- ing force. (Turn the adjuster ① out.)
Extent of adjustment:
Maximum Minimum
Fully turned in position20 clicks out (from maximum position)

YAMAHA WR400F (1999) - REGLAGE DE LA PRECONTRAINTE DE RESSORT DE L'AMORTISSEUR ARRIERE - 2

. STANDARDPosition:

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

YAMAHA WR400F (1999) - REGLAGE DE LA PRECONTRAINTE DE RESSORT DE L'AMORTISSEUR ARRIERE - 3

Standard position: About 11 clicks out *About 10 clicks out

  • For EUROPE

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 REBOND DE L'AMORTISSEUR ARRIERE

1. Régler:

  1. Adjust:

  2. Low compression damping force

By turning the adjuster ①.

Stiffer ⑧ Increase the low compression damping force. (Turn the adjuster 1 in.)

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

Extent of adjustment:
Maximum Minimum
Fully turned in position20 clicks out (from maximum position)

YAMAHA WR400F (1999) - Régler: - 1

. STANDARDPosition:

This is the position which is back by the specific number of clicks from the fully turned-in position. (Which align the punch mark ⑧ on the adjuster with the punch mark ⑥ on the high compression damping adjuster.)

YAMAHA WR400F (1999) - Régler: - 2

Standard position:

About 8 clicks out

*About 12 clicks out

  • For EUROPE

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 ARRIRE

1. Regler:

High compression damping force By turning the adjuster ①.

Stiffer ⑧ Increase the high compression damping force. (Turn the adjuster ① in.)

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

Extent of adjustment:
Maximum Minimum
Fully turned in position2 turns out (from maximum position)

YAMAHA WR400F (1999) - Regler: - 1

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 ⑧ on the adjuster with the punch mark ⑥ on the adjuster body.)

YAMAHA WR400F (1999) - Regler: - 2

Standard position: About 7/8 turns out *About 1 turns out

  • For EUROPE

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'AMORTISSEUR ARRIRE

1. Regler:

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.

EC36S002

SPOKES INSPECTION AND TIGHTENING

  1. Inspect:

  2. Spokes ①

Bend/damage Replace.

Loose spoke Retighten.

  1. Tighten:

Spokes 3Nm (0.3m·kg,2.2ft·lb)

NOTE:

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

EC36T000

WHEEL INSPECTION

  1. Inspect:

.Wheel runout

Elevate the wheel and turn it.

Abnormal runout Replace.

CONTROLE DE PRESSION DES PNEUS

  1. Mesurer:

  2. Pression des pneus

Hors Specification Regler.

YAMAHA WR400F (1999) - CONTROLE DE PRESSION DES PNEUS - 1

Pression des pneus standard:

100 kPa

(1,0kg / cm^2,15psi)

N.B.:

Exist play Replace.

EC36U012

STEERING HEAD INSPECTION AND ADJUSTMENT

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

  2. Check:

  3. Steering shaft

Grasp the bottom of the forks and gently rock the fork assembly back and forth.

Free play Adjust steering head.

  1. Check:

  2. Steering smooth action

Turn the handlebar lock to lock.

Unsmooth action Adjust steering ring nut.

  1. Adjust:

  2. Steering ring nut

Steering ring nut adjustment steps:

  • Remove the number plate.
  • Remove the handlebar and handle crown.
  • Loosen the ring nut ① using the ring nut wrench ②.

YAMAHA WR400F (1999) - Steering ring nut adjustment steps: - 1

Ring nut wrench:

YM-33975/90890-01403

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

YAMAHA WR400F (1999) - Steering ring nut adjustment steps: - 2

Ring nut wrench: YM-33975/90890-01403

YAMAHA WR400F (1999) - Steering ring nut adjustment steps: - 3

Ring nut (initial tightening): 38 Nm (3.8m· kg,27ft· lb)

  • Loosen the ring nut one turn.
  • Retighten the ring nut using the ring nut wrench.

WARNING

Avoid over-tightening.

YAMAHA WR400F (1999) - WARNING - 1

Ring nut (final tightening): 7 Nm (0.7 m·kg, 5.1 ft·lb)

  • Check the steering shaft by turning it lock to lock. If there is any binding, remove the steering shaft assembly and inspect the steering bearings.
    Install the handle crown ⑤ steering shaft nut ⑥ ,handlebar ⑦ ,handlebar holder ⑧ and number plate ⑨

NOTE:

The upper handlebar holder should be installed with the punched mark @ forward.
- Insert the end of fuel breather hose into the hole of the steering shaft.

CAUTION:

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

YAMAHA WR400F (1999) - CAUTION: - 1

Steering shaft nut: 145 Nm (14.5 m·kg, 105 ft·lb) Handlebar upper holder: 23 Nm (2.3 m·kg, 17 ft·lb) Pinch bolt (handle crown): 23 Nm (2.3 m·kg, 17 ft·lb)

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

① All control cable
② Brake and clutch lever pivots
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
Clutch cable end
10 Decompression cable end

A

Use Yamaha cable lube or eq

areas.

Use SAE10W-30 motor oil or suitable chain lubricants.
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.

YAMAHA WR400F (1999) - CAUTION: - 1

GRAISSAGE

  1. Inspect:

  2. 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 Re-gap.

YAMAHA WR400F (1999) - NOTE: - 1

Spark plug gap:

0.7 0.8 mm (0.028 0.031 in)

Standard spark plug:

CR8E (NGK)

U24ESR-N (DENSO)

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

YAMAHA WR400F (1999) - NOTE: - 2

  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 ⑧ the spark plug before torqu ing to specification ⑥

PARTIE ELECTRIQUE/CONTROLE DE LA BOUGIE ELEKTRISCHE ANLAGE/ZündKERZE KONTROLLIEREN SISTEMA ELECTRICO/INSPECCION DE LA BUJIA

PARTIE ELECTRIQUE CONTROLE DE LA BOUGIE

  1. Déposer:

Bougie

  1. Controller:

  2. Electrode ①

Usure/endommagement Changer.

IGNITION TIMING CHECK

  1. Remove:

.Timing plug ①

  1. Attach:

  2. Timing light
    Inductive tachometer

To the spark plug lead.

YAMAHA WR400F (1999) - IGNITION TIMING CHECK - 1

  1. Check:

  2. Ignition timing

Checking steps:

  • Start the engine and let it warm up. Let the engine run at the specified speed.

YAMAHA WR400F (1999) - Checking steps: - 1

  • Visually check the stationary pointer 当 is within the firing range ⑥ on the rotor. Incorrect firing range Check rotor and pickup assembly.

  • Install:

  • Timing plug

CONTROLE DE L'AVANCE A L'ALLUMAGE

  1. Déposser:

REPLACING THE HEADLIGHT BULBS

The following procedure applies to both of the headlight bulb.

  1. Remove:

Number plate

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

  1. Remove:

  2. Headlight bulb holder cover ①

  3. Detach:

  4. Headlight bulb holder ①

  5. Remove:

  6. 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.

  1. Install:

  2. 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.

  1. Attach:

  2. Headlight bulb holder

  3. Install:

  4. Headlight bulb holder cover

  5. Install:

Number plate

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

REMPLACER LES AMPOULES DU PHARE

The following procedure applies to both of the headlight.

  1. Adjust:

  2. Headlight beam (vertically)

Adjusting steps: ·Turn the adjusting screw ① in direction a or b.
Direction @ Headlight beam is raised.
Direction @ Headlight beam is lowered.

REGLAGES DES FAISCEAUX DES PHARES

③ Side covers removal

② Fuel tank removal

④ Number plate removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalSEAT, FUEL TANK AND SIDE COVERS REMOVAL Turn the fuel cock to "OFF". Disconnect the fuel hose.
1 Seat 1 2 Air scoop (left and right) 2 3 Fitting band 1 Remove on fuel tank side. 4 Bolt (fuel tank) 2 5 Fuel tank 1 6 Side cover (left) 1 7 Side cover (right) 1 8 Headlight coupler 1 9 Number plate 1

MOTEUR

SELLE, RESERVOIR A ESSENCE ET CACHES LATERAUX

YAMAHA WR400F (1999) - SELLE, RESERVOIR A ESSENCE ET CACHES LATERAUX - 1

Pour les USA, CDN

YAMAHA WR400F (1999) - SELLE, RESERVOIR A ESSENCE ET CACHES LATERAUX - 2
For USA
Except for USA
Extent of removal:
① Silencer removal
② Exhaust pipe removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalSide cover (right) Refer to “SEAT, FUEL TANK AND SIDE COVERS" section.
1 2 ②1 Bolt (clamp) 1 2 Bolt (silencer) 2 3 Silencer 1 4 Clamp 1 5 Nut (exhaust pipe) 1 6 Bolt (exhaust pipe) 2 7 Exhaust pipe 1 8 Gasket1

TUYAU D'ECHAPPEMENT ET SILENCIEUX

YAMAHA WR400F (1999) - TUYAU D'ECHAPPEMENT ET SILENCIEUX - 1

② Coolant reservoir removal

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalRADIATOR REMOVAL Drain the coolant. Seat, fuel tank and side Refer to "SEAT, FUEL TANK AND SIDE COVERS" section. Exhaust pipe Refer to "EXHAUST"Refer to "COOLANT REPLACEMENT" section in the CHAPTER 3. FUEL TANK AND SIDE COVERS" section. PIPE AND SILENCER" section.
11 Engine guard 1 2 Panel 2 Refer to "REMOVAL POINTS". 3 Clamp 8 4 Radiator (right) 1 5 Hose 2 1 6 Hose 3 1 7 Hose 4 1 8 Pipe 2/O-ring 1/1(Except for USA, CDN)

RADIATEUR

YAMAHA WR400F (1999) - RADIATEUR - 1

Extent of removal Order Part name Q'ty Remarks
19 Radiator breather hose 1
10 Radiator (left) 1
11 Hose 1 1
12 Pipe 1/O-ring 1/1
13 Coolant reservoir hose 1
14 Coolant reservoir breather hose 1
15 Coolant reservoir tank 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 WR400F (1999) - RADIATEUR - 2

YAMAHA WR400F (1999) - RADIATEUR - 3

EC453000

REMOVAL POINTS

EC453200

  • Unhook the panel first on the outer side ⑧ and then on the inner side.
    Take care not to bend the panel more than necessary.

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.

REMARQUES CONCERNANT LA MANIPULATION

A VERTISSEMENT

ASSEMBLY AND INSTALLATION

EC445350

Radiator

  1. Install:

Pipe 1 ①
- Hose 1 (2)
Pipe 2 ③
Hose 3 ④
Hose 4 ⑤

2.Install:

.Hose 2 ①
- Radiator (left) ②

  1. Install:

  2. Radiator breather hose ①

  3. Radiator (right) ② Refer to "CABLE ROUTING DIAGRAM" section in the CHAPTER 2.

  4. Install:

[For USA, CDN]
Panel ①

NOTE:

Take care not to bend the panel more than necessary.
- Hook the panel first on the inner side ⑧ and then on the outer side.

[Except for USA, CDN]
Panel ①
Bolt (radiator panel upper) ②

NOTE:

Fit the hook ⑧ on the inner side first into the radiator.

A For

USA,CDN

B Ex

cept for USA, CDN

Extent of removal: ① Carburetor removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalFuel tankCARBURETOR REMOVALRefer to “SEAT, FUEL TANK AND SIDECOVERS" section.
11 Clamp 12 Band 13 TPS coupler 14 Throttle cable cover 15 Throttle cable 26 Clamp (air cleaner joint) 1 Loosen the7 Clamp (carburetor joint) 2 Loosen the8 Carburetor9 Carburetor jointscrew (air cleaner joint).screws (carburetor joint).

CARBURATEUR

YAMAHA WR400F (1999) - CARBURATEUR - 1

Extent of removal: ① Carburetor disassembly

Extent of removal Order Part name Q'ty Remarks
1CARBURETOR DISASSEMBLY ①Breather hose 4 ②Valve lever housing cover 1 ③Screw (throttle shaft) 1 ④Throttle valve 1 ⑤Needle holder 1 ⑥Jet needle 1 ⑦Accelerator pump cover 1 ⑧Spring (accelerator pump) 1 ⑨Diaphragm (accelerator pump) 1 ⑩Air cut valve cover 1 ⑪Spring (air cut valve) 1 ⑫Diaphragm (air cut valve) 1 ⑬Float chamber1

DEMONTAGE DU CARBURATEUR

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

EC463000

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 WR400F (1999) - NOTE: - 1

EC464000

INSPECTION

EC464110

Carburetor

  1. Inspect:

  2. 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:

  1. Inspect:

  2. Main jet ①
    Pilot jet ②

  3. Needle jet ③
  4. Starter jet ④
    Main air jet ⑤
    Pilot air jet ⑥

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 WR400F (1999) - NOTE: - 1

EC464210

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.

EC464300

Throttle valve

  1. Check:

Free movement

Stick Repair or replace.

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

EC464400

Jet needle

  1. Inspect:

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

YAMAHA WR400F (1999) - Jet needle - 1

YAMAHA WR400F (1999) - Jet needle - 2

YAMAHA WR400F (1999) - Jet needle - 3

Standard clip position:

No.3 Groove

*No.4 Groove

  • Except for USA

2. Controller:

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 包 on the float.
  • Recheck the float height.

YAMAHA WR400F (1999) - NOTE: - 1

EC464600

Float

  1. Inspect:

Float ①

Damage Replace.

Hauteur du flotteur

  1. Mesurer:

Hauteur du flottcur

Hors specifications Regler.

YAMAHA WR400F (1999) - Hauteur du flotteur - 1

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.

  1. Inspect:

  2. Throttle shaft ①
    Spring ②
    .Lever 1 ③
    Spring 1 ④
    .Lever 2 ⑤
    Spring 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

Main air jet ①
Pilot air jet ②
Intake joint ③

  1. Install:

Spring 1①
.Lever 1 ②

To lever 2 ③

NOTE:

Make sure the spring 1 fits on the stopper @ of

the lever 2.

  1. Install:

Spring 2 ①

To lever 2 ②.

  1. Install:

  2. Push rod link lever assembly ①

NOTE:

Make sure the stopper 已 of the spring 2 fits

into the recess ⑥ in the carburetor.

  1. Install:

Plain washer ①
Circlip ②

2. Monter:

Spring ①
Joint collar ②

To throttle shaft ③.

NOTE: Install the bigger hook a of the spring fits on the stopper b of the throttle shaft pulley.

  1. Install:

Throttle shaft assembly ①
Plain washer (metal) ②
Plain washer (resin) ③
. Valve lever ④

NOTE:

Make sure the stopper 已 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 (6) to the stopper (7) of the throttle shaft assembly pulley.

  1. Install:

  2. Push rod ①

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

7. Installer:

-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 WR400F (1999) - Note the following installation points: - 1

Pilot screw:

1-5/8 turns out
*1-1/2 turns out
(for reference only)

  • Except for USA

YAMAHA WR400F (1999) - Note the following installation points: - 2

13.Install:

Float chamber ①
Screw(float chamber) ②
Cable holder (throttle stop screw cable) ③
Hose holder (carburetor breather hose) ④

10. Monter:

  • 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
.Cover ④
. Screw (cover) ⑤

16.Install:

Jet needle ①
.Needle holder ②
- Throttle valve plate ③ To throttle valve ④

17.Install:

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

NOTE: Install the valve lever rollers ③ into the slits a of the throttle valve.

18.Install:

.Gasket ①
- Valve lever housing cover ②
.Screw ③

14. Monter:

  • Carburetor breather hose ①

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

NOTE:

Install the breather hose to the carburetor so that the hose does not bend near where it is installed.

EC465360

Carburetor installation

  1. Install:

  2. Carburetor joint ①

NOTE:

Install the projection ⑧ on the cylinder between the carburetor joint slots ⑥

  1. Install:

-Carburetor ①

NOTE:

Install the projection between the carburetor joint slots.

  1. Tighten:

Screw (air cleaner joint) ①
Screw (carburetor joint) ②

  1. Install:

  2. Throttle cable ①

  3. Adjust:

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

  1. Install:

  2. Throttle cable cover ①
    Screw (throttle cable cover) ②

YAMAHA WR400F (1999) - Carburetor installation - 1

4 Nm (0.4 m·kg, 2.9 ft·lb)

NOTE:

Install the throttle cable cover with its pawl ⑧ hung on the carburetor.

  1. Install:

TPS (throttle position sensor) coupler ①
- Band ②

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

6. Monter:

Extent of removal: ① Cylinder head cover removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalSeat andCYLINDER HEAD COVER REMOVAL fuel tank Refer to "SEAT, FUEL TANK AND RADIATOR Refer to "RADIATOR" section. Carburetor Refer to "CARBURETOR" section.SIDE COVERS" section.
11 Spark plug cap 1 2 Engine upper bracket (right) 1 3 Engine upper bracket (left) 1 4 Cylinder head breather hose 1 5 Oil tank breather hose 1 6 Bolt (cylinder head cover) 2 7 Cylinder head cover 1 8 Gasket 1 9 Timing chain guide (upper) 1

ARBRES A CAMES

COUVERCLE DE CULASSE

Extent of removal: ① Timing chain removal ② Camshaft removal

Extent of removal Order Part name Q'ty Remarks
CAMSHAFTS REMOVAL1 Timing plug 12 Straight plug 13 Tensioner cap bolt 14 Timing chain tensioner 15 Gasket 16 Bolt (camshaft cap) 107 Camshaft cap 28 Clip 29 Dowel pin 410 Exhaust camshaft11 Intake camshaftRefer to “REMOVAL POINTS”.

ARBRES A CAMES

.Timing plug ①
- Straight plug ②

  1. Align:

"I" mark

With stationary pointer.

Checking steps:

  • Turn the crankshaft counterclockwise with a wrench.
    Align the "I" mark ⑧ on the rotor with the stationary pointer ⑥ on the crankcase cover. When the "I" mark is aligned with the stationary pointer, the piston is at the Top Dead Center (T.D.C.).

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 已 on the intake camshaft must align with the cylinder head surface, as shown in the illustration.
- If there is no clearance, rotate the crank-shaft counterclockwise one turn.

  1. Loosen:

  2. Camshaft sprocket bolts
    Tensioner cap bolt ①

  3. Remove:

  4. Timing chain tensioner ②

  5. Remove:

Bolt (camshaft cap) ①
.Camshaft caps ②

NOTE:

Remove the bolts (camshaft cap) in a crisscross pattern, working from the inside out.

CAUTION:

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

POINTS DE DEPOSE

Arbre a cames

  1. Déposcer:
  1. Remove:

  2. Clips
    Dowel pins
    .Exhaust camshaft ①

  3. 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 lobes

Pitting/scratches/blue discoloration Replace.

2.Measure:

.Cam lobes length 包 and

Out of specification Replace.

YAMAHA WR400F (1999) - Camshaft - 1

Cam lobes length limit: Intake:

⑧ 31.6 mm (1.244 in)

⑥ 22.85 mm (0.900 in)

Exhaust:

⑥ 31.1 mm (1.224 in)

⑥ 22.85 mm (0.900 in)

  1. Measure:

Runout (camshaft)

Out of specification Replace.

YAMAHA WR400F (1999) - Camshaft - 2

Runout (camshaft): Less than 0.03 mm (0.0012 in)

4.Measure:

  • Camshaft-to-cap clearance

Out of specification Measure bearing diameter (camshaft)

YAMAHA WR400F (1999) - Camshaft - 3

Camshaft-to-cap clearance: 0.020 ~ 0.054 mm

(0.0008 ~ 0.0021 in)

: 0.08 mm (0.003 in)

  1. Déposser:

@ 31,6 mm (1,244 in)

⑥ 22,85 mm (0,900 in)

Echappement:

@ 31,1 mm (1,224 in)
⑤ 22,85mm(0,900in)

PRÜFUNG

Nockenwelle

  1. Kontrollieren:

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

YAMAHA WR400F (1999) - Nockenwelle - 1

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

NOTE:

  • Tighten the bolts (camshaft cap) in a crisscross 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:

Bearing diameter (camshaft) @

Out of specification Replace the camshaft.

Within specification Replace camshaft case and camshaft caps as a set.

YAMAHA WR400F (1999) - Measure: - 1

Bearing diameter (camshaft):

21.967\~21.980mm

(0.8648 ~ 0.8654 in)

Camshaft sprocket

1. Inspect:

Camshaft sprocket

Wear/damage Replace the camshaft Assembly and timing chain as a set.

Etapes de la mesure:

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

1.Install:

.Exhaust camshaft ①
Intake camshaft ②

Installation steps:

  • Turn the crankshaft counterclockwise until the "l" mark ④ on the rotor is aligned with the stationary pointer ⑥ on the crankcase cover.
  • 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 exhaust cam sprocket punch mark and the intake cam sprocket punch mark align with the surface of the cylinder head.

CAUTION:

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

Install the dowel pins, clips and camshaft caps ④.

YAMAHA WR400F (1999) - CAUTION: - 1

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

NOTE: Tighten the camshaft cap bolts 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 WR400F (1999) - CAUTION: - 2

  1. Install:

  2. 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 ⑧ facing upward, install the gasket ① and the chain tensioner ② ,and tighten the bolt ③ to the specified torque.

YAMAHA WR400F (1999) - Installation steps: - 1

YAMAHA WR400F (1999) - Installation steps: - 2

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

  • 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 WR400F (1999) - Installation steps: - 3

Cap bolt (timing chain tensioner): 7 Nm (0.7 m·kg, 5.1 ft·lb)

YAMAHA WR400F (1999) - Installation steps: - 4

  1. Turn:

Crankshaft Counterclockwise several turns.

  1. Check:

  2. Rotor "I" mark Align with the crankcase stationary pointer.

  3. Camshaft match marks
  4. Align with the cylinder head surface.
  5. Out of alignment Adjust.

  6. Monter les goujons, les clips et les chapeaux d'arbre à cames ④.

YAMAHA WR400F (1999) - Installation steps: - 5

Boulon de chapeau

d'arbre à cames:

10Nm

(1,0m· kg,7,2ft· lb)

N.B.:

Extent of removal: ① Cylinder head removal

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalSeat and CYLINDER HEAD REMOVAL fuel tank Refer to "SEAT, FUEL TANK AND EXHAUST pipe and silencer Radiator Refer to "RADIATOR" section. Carburetor Refer to "CARBURETOR" section. Camshaft Refer to "CAMSHAFTS"ReferSIDE COVERS" section. to "EXHAUST PIPE AND SILENCER" section.
11 Decompression cable 12 Cable guide 13 Bolt 4 Decompression shaft 5 Oil delivery pipe 6 Nut (M6) 7 Nut (M8) 8 Bolt (L = 150 mm) 9 Bolt (L = 160 mm) 10 Cylinder headsection.

CULASSE

CULASSE

YAMAHA WR400F (1999) - CULASSE - 1

Extent of removal Order Part name Q'ty Remarks
11 Gasket 112 Dowel pin 213 Timing chain guide (front) 1

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

  1. Inspect:

Cylinder head

Scratches/damage Replace.

  1. Measure:

Cylinder head warpage

Out of specification Resurface.

YAMAHA WR400F (1999) - CULASSE - 2

Cylinder head warpage:

Less than 0.05mm (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.

ASSEMBLY AND INSTALLATION

1.Install:

Cylinder head
- Bolts (1 ~ 4)

44Nm(4.4m·kg,32ft·lb)

Bolt (5)

10Nm(1.0m·kg,7.2ft·lb)

Nuts (6, 7)

20Nm(2.0m·kg,14ft·lb)

Nuts (8, 9)

10Nm(1.0m·kg,7.2ft·lb)

NOTE:

Follow the numerical order shown in the illustration. Tighten the bolts and nuts in two stages.

CONTROLE

Culasse

  1. Eliminer:

Extent of removal: ① Valve removal

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalCylinderVALVES AND VALVE SPRINGS REMOVAL head Refer to "CYLINDER HEAD" section.
11 Valve lifter 5 2 Adjusting pad 5 3 Valve cotter 10 4 Valve retainer 5 5 Valve spring 5 6 Stem seal 5 7 Valve spring seat 5 8 Exhaust valve 2 9 Intake valve3Use special tool. Refer to "REMOVAL POINTS".

SOUPAPES ET RESSORTS DE SOUPAPE

SOUPAPES ET RESSORTS DE SOUPAPE

  1. Remove:

  2. Valve lifters ①

  3. Pads ②

NOTE:

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

  1. Check:

  2. 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.

  • Remove:

. Valve cotters

NOTE:

Attach a valve spring compressor ① and attachment ② between the valve spring retainer and the cylinder head to remove the valve cotters.

YAMAHA WR400F (1999) - Checking steps: - 1

Valve spring compressor:

YM-04019/90890-04019

Attachment:

YM-04108/90890-04108

POINTS DE DEPOSE

  1. Déposser:
  1. Measure:

  2. Stem-to-guide clearance

Stem-to-guide clearance = valve guide inside diameter a - valve stem diameter b

Out of specification Replace the valve guide.

YAMAHA WR400F (1999) - POINTS DE DEPOSE - 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^ (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.

YAMAHA WR400F (1999) - NOTE: - 1

Valve guide remover:

Intake 4.5mm (0.18 in)

YM-4116/90890-04116

Exhaust 5.0mm (0.20 in)

YM-4097/90890-04097

Valve guide installer:

Intake

YM-4117/90890-04117

Exhaust

YM-4098/90890-04098

Valve guide reamer:

Intake 4.5mm (0.18 in)

YM-4118/90890-04118

Exhaust 5.0mm (0.20 in)

YM-4099/90890-04099

CONTROLE

Soupape

Escape 5,0 mm (0,20 in)

YM-4097/90890-04097

Escape 5,0 mm (0,20 in)

YM-4099/90890-04099

YAMAHA WR400F (1999) - Soupape - 1

YAMAHA WR400F (1999) - Soupape - 2

YAMAHA WR400F (1999) - Soupape - 3

NOTE: After replacing the valve guide reface the valve seat.

  1. Inspect:

  2. Valve face Pitting/wear Grind the face.

  3. Valve stem end Mushroom shape or diameter larger than the body of the stem Replace.

  4. Measure:

  5. Margin thickness @ Out of specification Replace.

YAMAHA WR400F (1999) - Soupape - 4

Margin thickness:

Intake:

1.0 mm (0.039 in)

: 0.85 mm (0.033 in)

Xhaust:

1.0 mm (0.039 in)

: 0.85 mm (0.033 in)

  1. Measure:

Runout (valve stem)

Out of specification Replace.

YAMAHA WR400F (1999) - Margin thickness: - 1

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.

  • Eliminate:

Carbon deposits

From the valve face and valve seat.

  1. Inspect:

  2. Valve seats

Pitting/wear Reface the valve seat.

  1. Measure:

  2. Valve seat width ^④

Out of specification Reface the valve seat.

YAMAHA WR400F (1999) - Runout limit: - 1

Valve seat width:

Intake:

0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)

: 1.5 mm (0.06 in)

Exhaust:

0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)

: 1.5 mm (0.06 in)

N.B.:

  • 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.

9. Lap:

. Valve face
. Valve seat

NOTE:

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

YAMAHA WR400F (1999) - NOTE: - 1

YAMAHA WR400F (1999) - NOTE: - 2

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.

Etapes de la mesure:

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 re-lap the valve seat.

Valve spring

  1. Measure:

  2. Valve spring free length @

Out of specification Replace.

YAMAHA WR400F (1999) - Valve spring - 1

  1. Measure:

Compressed spring force @

Out of specification Replace.

6 Installed length

YAMAHA WR400F (1999) - Valve spring - 2

  1. Measure:

Spring tilt ⑧

Out of specification Replace.

YAMAHA WR400F (1999) - Valve spring - 3

N.B.:

Force du ressort comprime @

Hors specifications Remplacer.

Longueur monté

YAMAHA WR400F (1999) - N.B.: - 1

Force duressort com

prime:

Admission:

117a 134N

Scratches/damage Replace both lifters and cylinder head.

ASSEMBLY AND INSTALLATION

  1. Apply:

Molybdenum disulfide oil

Onto the valve stem and valve stem seal.

  1. Install:

  2. Valves ①

  3. Valve spring seats ②
  4. Valve stem seals ③
  5. Valve springs ④
  6. Valve spring retainers ⑤

NOTE:

Make sure that each valve is installed in its original place, also referring to the embossed mark as follows.

Intake (right/left): "5BE:"

Intake (middle): "5BE."

Exhaust: "5BE"

Install the valve springs with the larger pitch @ facing upwards.

們 Smaller pitch

  1. Install:

Valve cotters

NOTE:

While compressing the valve spring with a valve spring compressor ① and attachment ② install the valve cotters.

YAMAHA WR400F (1999) - ASSEMBLY AND INSTALLATION - 1

Valve spring compressor:

YM-04019/90890-04019

Attachment:

YM-04108/90890-04108

Pousoir de soupape

  1. Contrôler:
  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.

  1. Install:

  2. Adjusting pad ①
    -Valve lifter ②

NOTE:

Lubricate the valve lifters and pads with molybdenum disulfide oil.
- 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 VALVULAS Y MUELLES DE VALVULA

Extent of removal: ① Cylinder removal ② Piston removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalCYLINDER AND PISTON REMOVAL Cylinder head Refer to "CYLINDER HEAD" section.
1 21 Bolt (cylinder) 1 2 Cylinder 1 3 Gasket 1 4 Dowel pin 2 5 Dowel pin/O-ring 1/1 6 Piston pin clip 2 7 Piston pin 1 8 Piston 1 9 Piston ring set1Use special tool. Refer to "REMOVAL POINTS".

CYLINDRE ET PISTON

CYLINDRE ET PISTON

  • 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 ④.

YAMAHA WR400F (1999) - CYLINDRE ET PISTON - 1

Piston pin puller: YU-01304/90890-01304

CAUTION:

Do not use a hammer to drive the piston pin out.

Piston ring

  1. Remove:

Piston rings

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

YAMAHA WR400F (1999) - Cylinder and piston - 1

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

Piston

  1. Déposser:

Agrafed'axe depiston ①
-Axe de piston ②
Pistons ③

N.B.:

Cylinder bore “C”92.00 ~ 92.01 mm (3.6220 ~ 3.6224 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” with a micrometer. @ 9 mm (0.35 in) from the piston bottom edge.
Piston size P
Standard91.945 ~ 91.960 mm (3.6199 ~ 3.6205 in)
·If out of specification, replace the piston and piston rings as a set. 3rd step: ·Calculate the piston-to-cylinder clearance with 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) <Limit>: 0.15 mm (0.006 in)
·If out of specification, replace the cylinder, and replace the piston and piston rings as set.

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 <Limit>
Top ring0.030 ~ 0.065 mm (0.0012 ~ 0.0026 in)0.13 mm (0.005 in)
2nd ring0.020 ~ 0.055 mm (0.0008 ~ 0.0022 in)0.13 mm (0.005 in)
  1. Position:

Piston ring

In cylinder.

NOTE:

Insert a ring into the cylinder and push it approximately 10mm (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.

⑥ 10mm (0.39 in)

  1. 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.

End gap
Standard Limit
Top ring0.20 ~ 0.35 mm (0.008 ~ 0.014 in)0.7 mm (0.028 in)
2nd ring0.40 ~ 0.55 mm (0.016 ~ 0.022 in)0.8 mm (0.031 in)
Oil ring0.20 ~ 0.50 mm (0.01 ~ 0.02 in)

Segment de piston

  1. Mesurer:

Replace, then inspect the lubrication system.

  1. Measure:

  2. Piston pin-to-piston clearance

YAMAHA WR400F (1999) - Segment de piston - 1

YAMAHA WR400F (1999) - Segment de piston - 2

Measurement steps:

Measure the outside diameter (piston pin) a. If out of specification, replace the piston pin

YAMAHA WR400F (1999) - Measurement steps: - 1

Outside diameter (piston pin): 17.991 ~ 18.000 mm (0.7083 ~ 0.7087 in)

Measure the inside diameter (piston) 6.

YAMAHA WR400F (1999) - Measurement steps: - 2

Inside diameter (piston): 18.004 ~ 18.015 mm (0.7088 ~ 0.7093 in)

Calculate the piston pin-to-piston clearance with the following formula.

Piston pin-to-piston clearance = Inside diameter (piston) ⑥ - Outside diameter (piston pin) ⑧

If out of specification, replace the piston.

YAMAHA WR400F (1999) - Measurement steps: - 3

Piston pin-to-piston clearance: 0.004 ~ 0.024 mm (0.00016 ~ 0.00094 in) : 0.07 mm (0.003 in)

YAMAHA WR400F (1999) - Measurement steps: - 4

ASSEMBLY AND INSTALLATION

Piston

1.Install:

Piston rings

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. Contröller:

-Axe de piston

. Top ring
.2nd ring
Oil ring

Offset the piston ring end gaps as shown.

Top ring end
⑥ 2nd ring end
Oil ring end (upper)
Oil ring
Oil ring end (lower)

  1. Install:

Piston ①
Piston pin ②
Piston pin clips ③

New

NOTE:

  • Apply engine oil onto the piston pin and piston.
  • Be sure that the arrow mark ⑧ 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.

  • Lubricate:

Piston
Piston rings
Cylinder

NOTE:

Apply a liberal coating of engine oil.

Cylinder

  1. Install:

.Gasket ①

New

Cylinder ②

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 damper ④ during installation.

2. Positionner:

YAMAHA WR400F (1999) - Positionner: - 1
Extent of removal:
① Push rod and push lever removal
② Push rod 1 disassembly
③ Friction plate and clutch plate removal ④ Clutch housing removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalDrain theCLUTCH REMOVAL engine oil. Refer to "ENGINE OIL Brake pedal Refer to "ENGINE REMOVAL" Clutch cable Disconnect at engine side.REPLACEMENT" section in the CHAPTER 3. section.
1 2 41 Clutch cover 1 2 Gasket 1 3 Dowel pin 2 4 Clutch spring 5 5 Pressure plate 6 Push rod 1 7 Circlip 8 Plain washer 9 Bearing 10 Push rod 21 1 1 1 1 11

EMBRAYAGE

EMBRAYAGE

Extent of removal Order Part name Q'ty Remarks
3411 Friction plate 2 [ø116 mm (4.57 in)] 112 Clutch plate 713 Friction plate 1 [ø112 mm (4.41 in)] 714 Nut 115 Look washer 116 Clutch boss 117 Thrust washer 118 Clutch housing 119 Push lever 1Use special tool.Refer to "REMOVAL POINTS".

Straighten the lock washer tab and use the clutch holding tool 4 to hold the clutch boss.

YAMAHA WR400F (1999) - EMBRAYAGE - 1

For USA and CDN
Except for USA and CDN

EC494000

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:

Circumferential play
Free play exists Replace.
Gear teeth
Wear/damage Replace.

EC484400

Clutch spring

  1. Measure:

  2. Clutch spring free length @

Out of specification Replace springs as a set.

Clutch spring free length:
Standard <Limit>
44 mm (1.73 in)43 mm (1.69 in)

POINTS DE DEPOSE

Noix d'embrayage

Friction plate thickness

Out of specification Replace friction plate as a set.

Measure at all four points.

YAMAHA WR400F (1999) - Noix d'embrayage - 1

Friction plate thickness:

Friction plate 1 [ø112 mm (4.41 in)]:

2.72~2.88mm

(0.107 ~ 0.113 in)

: 2.5 mm (0.098 in)

Friction plate 2 [Ø116 mm (4.57 in)]:

2.92\~3.08mm

(0.115 ~ 0.121 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 WR400F (1999) - Clutch plate - 1

Warp limit:

0.05 mm (0.002 in)

Push lever

  1. Inspect:

  2. Push lever ①

Wear/damage Replace.

EC484810

Push rod

  1. Inspect:

  2. Push rod 1 ①
    Bearing ②
    Plain washer ③
    . push rod 2 ④

Wear/damage/bend Replace.

EC495000

ASSEMBLY AND INSTALLATION

Push lever

1.Install:

  • Push lever ①

NOTE:

Apply the engine oil on the oil seal lip and push lever.

Disque de friction

1. Mesurer:

[0112 mm (4,41 in)]:

2,72\~2,88 mm

(0,107 0,113in)

: 2,5 mm

(0,098 in)

Disco de fricción 2

[0116 mm (4,57 in)]:

2.92\~3.08mm

(0,115~0,121 in)

: 2,7 mm

(0,106 in)

Discos de embrague

1. Medir:

  1. Install:

  2. Lock washer ①

New

Nut (clutch boss) ②

75Nm(7.5m·kg,54ft·lb)

NOTE:

Use the clutch holding tool ③ to hold the clutch boss.

YAMAHA WR400F (1999) - Medir: - 1

For USA and CDN
Except for USA and CDN

  1. Bend the lock washer ① tab.

  2. Install:

  3. Friction plate 1 [ø112 mm (4.41 in)] ①

  4. Clutch plate ②
  5. Friction plate 2 [Ø116 mm (4.57 in)] ③

NOTE:

Install the clutch plates and friction plates alternately on the clutch boss, starting with a friction plate 1 and ending with a friction plate 2.
- Apply the engine oil on the friction plates and clutch plates.

  1. Install:

-Bearing ①
Plain washer ②
Circlip ③ New

To push rod 1 ④.

NOTE:

Apply the engine oil on the bearing and plain washer.

Embrayage

  1. Monter:

Rondelle-frein ①

New

(an Druckstange 1 ④)

HINWEIS:

Apply the engine oil on the push rod 1, 2.

  1. Install:

Pressure plate ①

NOTE: Align the much mark ⑧ on the pressure plate with the punched mark ⑥ on the clutch boss.

  1. Install:

  2. Clutch spring
    Bolt (clutch spring)

8Nm (0.8m· kg,5.8ft· lb)

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

  1. Install:

Gasket (clutch cover) ①

New

Dowel pin ②

  1. Install:

  2. Clutch cover ①

  3. Bolt (clutch cover)

10Nm(1.0m·kg,7.2ft·lb

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

5. Monter:

YAMAHA WR400F (1999) - Monter: - 1
Extent of removal: ① Oil filter removal ② Water pump removal
③ Crankcase (right) removal

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalDrain theOIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) REMOVAL engine oil. Refer to "ENGINE OIL REPLACEMENT" Drain the coolant. Refer to "COOLANT Exhaust pipe Refer to "EXHAUST Brake pedal Refer to "ENGINE REMOVAL" Clutch cover Refer to "CLUTCH" section.Refer to "ENGINE OIL REPLACEMENT" section in the CHAPTER 3.
12 Oil filter cover 1
23 Coolant pipe 2
34 Water pump housing 1
45 Pin delivery pipe
56 Oil delivery pipe

FILTRE A HUILE, POMPE A EAU ET COUVERCLE DE CARTER (DROIT) FILTRE A HUILE, POMPE A EAU ET COUVERCLE DE CARTER (DROIT)

YAMAHA WR400F (1999) - FILTRE A HUILE, POMPE A EAU ET COUVERCLE DE CARTER (DROIT) FILTRE A HUILE, POMPE A EAU ET COUVERCLE DE CARTER (DROIT) - 1

Extent of removal Order Part name Q'ty Remarks
7 Oil hose 18 Kick crank 19 Crankcase cover (right) 110 Gasket 111 Dowel pin/O-ring 4/212 Impeller 113 Plain washer 114 Impeller shaft 115 Oil seal 1 16 Oil seal 2 17 Bearing1Refer to “REMOVAL POINTS”.

FILTRE A HUILE, POMPE A EAU ET COUVERCLE DE CARTER (DROIT) ÖLFILTER, WASSERPUMPE UND KURBELGHEAUSEDECKEL (RECHTS) FILTRO DE ACEITE, BOMBA DE AGUA Y CUBIERTA DEL CARTER (DERECHO)

ENG

YAMAHA WR400F (1999) - FILTRE A HUILE, POMPE A EAU ET COUVERCLE DE CARTER (DROIT) ÖLFILTER, WASSERPUMPE UND KURBELGHEAUSEDECKEL (RECHTS) FILTRO DE ACEITE, BOMBA DE AGUA Y CUBIERTA DEL CARTER (DERECHO) - 1

Hold the impeller shaft on its width across the flats ④ 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:
    -Bearing ①
  2. Remove:
    . Oil seal ①

EC4G4000

INSPECTION

EC444200

Impeller shaft

  1. Inspect:

Impeller shaft ①

Bend/wear/damage Replace.

Fur deposits Clean.

POINTS DE DEPOSE

Axe de turbine

  1. Déposcer:

Rotate inner race with a finger.

Rough spot/seizure Replace.

EC444400

Oil seal

  1. Inspect:

. Oil seal

Wear/damage Replace.

YAMAHA WR400F (1999) - Oil seal - 1

EC4G5000

ASSEMBLY AND INSTALLATION

EC4G5110

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 inward.

Bearing

  1. Install:

-Bearing ①

NOTE:

Install the bearing by pressing its outer race parallel.

YAMAHA WR400F (1999) - NOTE: - 1

Roulement

  1. Controller:

Roulement

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 engine oil 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 remove the impeller.

Crankcase cover (right)

  1. Install:

Dowel pin ①
-O-ring ②
Collar ③
.Gasket ④

YAMAHA WR400F (1999) - Crankcase cover (right) - 1

2.Install:

Crankcase cover (right) ①

Bolt

YAMAHA WR400F (1999) - Crankcase cover (right) - 2

NOTE:

  • When installing the crankcase cover onto the crankcase, be sure that the impeller shaft end ② aligns with the balancer end slot ③.
  • Tighten the bolts in stage, using a crisscross pattern.

Axe de turbine

  1. Monter:

Install the kick crank so that the kick crank is as vertical as possible with the distance @ between the kick crank and the frame being 5mm (0.20 in) or more.

2.Install:

.Oil hose ①

Bolt (oil hose) ②

10Nm(1.0m·kg,7.2ft·lb)

  1. Install:

Copper washer ①

Oil delivery pipe ②

.Union bolt (M8) ③

18Nm(1.8m·kg,13ft·lb)

.Union bolt (M10) ④

20Nm(2.0m·kg,14ft·lb)

Water pump housing

  1. Install:

.Pin ①

-O-ring ②

New

  1. Install:

Water pump housing ①

Bolt (water pump housing) ②

10 Nm (1.0 m · kg, 7.2 ft · lb)

Plain washer ③ New

Coolant drain bolt ④

10Nm(1.0m·kg,7.2ft·lb)

Démarreur au pied

  1. Monter:

Extent of removal: ① Balancer drive gear ② Balancer

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalClutch housing Refer to "CLUTCH" section. Crankcase cover (right) Refer to Stator Refer to "CDI MAGNETO" section.Filter, WATER PUMP AND CRANKCASE COVER (RIGHT)" section.
1 ②↑1 Nut (primary drive gear) 12 Nut (balancer) 13 Lock washer 14 Primary drive gear 15 Balancer drive gear 6 Straight key7 Lock washer 18 Balancer driven gear 19 Balancer1Refer to "REMOVAL POINTS".
1

BALANCIER

BALANCIER

YAMAHA WR400F (1999) - BALANCIER - 1

Balancer drive gear and balancer driven gear

  1. Straighten the lock washer tab.
  2. Loosen:

.Nut (primary drive gear) ①
Nut (balancer) ②

NOTE:

Place an aluminum plate ③ between the teeth of the balancer drive gear ④ and driven gear ⑤

Balancer

  1. Remove:

Balancer ①

NOTE:

When removing the balancer shaft, align the center of the balancer shaft weight ⑧ along the line connecting the centers of the crankshaft and balancer shaft.

INSPECTION

Primary drive gear, balancer drive gear and balancer driven gear

  1. Inspect:

Primary drive gear ①
Balancer drive gear ②
Balancer drive gear ③

Wear/damage Replace.

Balancer

  1. Inspect:

Balancer

Cracks/damage Replace.

POINTS DE DEPOSE

ASSEMBLY AND INSTALLATION

Balancer, balancer drive gear and balancer driven gear

  1. Install:

Balancer ①

NOTE:

When installing the balancer shaft, align the center of the balancer shaft weight (a) along the line connecting the centers of the crankshaft and balancer shaft.

2.Install:

Balancer driven gear ①

NOTE:

Install the balancer driven gear onto the balancer while aligning the punch mark ⑧ on the balancer driven gear with the protrusion ⑥ on the balancer end.

3.Install:

. Straight key ①
Balancer drive gear ②
Primary drive gear ③

NOTE:

Align the punched mark ⑧ on the balancer drive gear with the punched mark ⑥ on the balancer driven gear.

  1. Install:

  2. Lock washer ①
    .Nut (balancer) ②

50Nm(5.0m·kg,3.6ft·lb)

  • Nut (primary drive gear) ③

75Nm(7.5m·kg,54ft·lb)

NOTE:

Place an aluminum plate ④ between the teeth of the balancer drive gear ⑤ and driven gear ⑥.

  1. Bend the lock washer tab.

ASSEMBLAGE ET INSTALLATION

Extent of removal: ① Oil pump removal ② Oil pump disassembly

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalOIL PUMP REMOVAL AND DIS-ASSEMBLYClutch housing Refer to "CLUTCH" Crankcase cover (right) Refer tosection, "OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)" section.
11 Circlip 12 Plate washer 13 Oil pump drive gear 14 Oil pump assembly 15 Dowel pin 16 Outer rotor 2 17 Circlip 18 Inner rotor 29 Pin10 Oil pump cover11 Outer rotor 1 112 Inner rotor 11

POMPE A HUIL

POMPE A HUIL

Extent of removal Order Part name Q'ty Remarks
13 Pin 1 14 Washer 1 15 Oil pump drive shaft 1 16 Rotor housing 1
  • Oil pump drive gear
  • Oil pump driven gear
  • Rotor housing
  • Oil pump cover Cracks/wear/damage Replace.

YAMAHA WR400F (1999) - POMPE A HUIL - 1

2. Measure:

Tip clearance @

Between the inner rotor ① and the outer rotor ②.

Side clearance 6

Between the outer rotor ② and the rotor housing ③

Out of specification Replace the oil pump.

YAMAHA WR400F (1999) - Measure: - 1

Tip clearance 已

0.07 ~ 0.12 mm (0.0028 ~ 0.0047 in)

: 0.15 mm (0.006 in)

Tip clearance 6:

0.09 ~ 0.15 mm (0.0035 ~ 0.0059 in)

: 0.22 mm (0.009 in)

Side clearance

0.03 ~ 0.08 mm (0.0012 ~ 0.0031 in)

: 0.15 mm (0.006 in)

YAMAHA WR400F (1999) - Measure: - 2

3. Check:

Unsmooth Repeat steps #1 and #2 or replace the defective parts.

YAMAHA WR400F (1999) - Check: - 1

ASSEMBLY AND INSTALLATION

Oil pump

1.Install:

  • Oil pump drive shaft ①
  • Washer ②
    Pin ③
  • Inner rotor 1④

NOTE:

Fit the pin into the groove in the inner rotor 1.

CONTROLE

Pompe à huié

  1. Contrôler:

Align the match mark ⑧ on the inner rotor 1 with the match mark ⑤ on the outer rotor 1.

  1. Install:

. Oil pump cover ①
. Screw (oil pump cover) ②

4Nm(0.4m·kg,2.9ft·lb)

Pin ③
. Inner rotor 2 ④
Circlip ⑤ New

NOTE: Fit the pin into the groove in the inner rotor 2.

  1. Install:

Outer rotor 2 ①
Dowel pin ②
. Oil pump assembly ③
Bolt (oil pump assembly) ④

10Nm(1.0m·kg,7.2ft·lb)

5.Install:

. Oil pump drive gear ①
Plate washer ②
Circlip ③ New

2. Monter:

Rotorextérieur1 ①

N.B.:

KICK AXLE AND SHIFT SHAFT

KICK AXLE AND SHIFT SHAFT

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 1

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 2
Extent of removal:
① Kick axle removal ② Kick axle disassembly
③ Shift shaft ④ Segment removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removal Shift pedal KICK AXLE AND SHIFT SHAFT REMOVAL Refer to "ENGINE REMOVAL" section. Oil pump Refer to "OIL PUMP" section.
1 Kick idle gear 1 2 Kick axle assembly 1 Refer to "REMOVAL POINTS". 3 Spring guide 1 4 Torsion spring 1 5 Ratchet wheel 1 6 Kick gear 1 7 Kick axle 1 8 Plain washer 9 Shift shaft 10 Collar 11 Torsion spring 1 12 Roller

AXE DE DEMARREUR AU PIED ET ARBRE DE SELECTEUR

NOTE: Unhook the torsion spring ② from the hole @ 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:

  2. Bolt (segment) ①
    Segment ②

NOTE:

Turn the segment counterclockwise until it stops and loosen the bolt.

EC4C4000

INSPECTION

EC4B4100

Kick axle and ratchet wheel

  1. Check:
    Ratchet wheel smooth movement Unsmooth movement Replace.
  2. Inspect:
  3. Kick axle ① Wear/damage Replace.

Kick gear, kick idle gear and ratchet wheel

  1. Inspect:

  2. Kick gear ①

  3. Kick idle gear ②
    Ratchet wheel ③
    Gear teeth ⑧ Wear/damage Replace.

POINTS DE DEPOSE

  1. Inspect:

  2. Stopper lever ①

Wear/damage Replace.

Torsion spring ②

Broken Replace.

EC4C5000

ASSEMBLY AND INSTALLATION

Segment

1.Install:

Segment ①
Bolt (segment)

30Nm (3.0m· kg,22ft· lb)

NOTE:

Align the notch ⑧ on the segment with the pin ⑥ on the shift cam.

EC4B5111

Stopper lever

  1. Install:

Torsion spring ①
- Stopper lever ②
Bolt (stopper lever) ③

10Nm(1.0m·kg,7.2ft·lb)

NOTE:

Align the stopper lever roller with the slot on segment.

Arbre de selecteur

  1. Contrôler:

The shift lever assembly is installed at the same time as the shift guide.
- Apply the engine oil on the bolt (segment) shaft.

  1. Install:

  2. Bolt (shift guide) ①

YAMAHA WR400F (1999) - Arbre de selecteur - 1

10Nm(1.0m·kg,7.2ft·lb)

EC4C5301

Shift shaft

  1. Install:

  2. Roller ①
    Collar ②
    Torsion spring ③

  3. Shift shaft ④

NOTE:

Apply the engine oil on the roller and shift shaft.

AXE DE DEMARREUR AU PIED ET ARBRE DE SELECTEUR

KICKSTARTERWILLE UNDSCHALTWILLE

EJE DEL PEDAL Y EJE DE SELECTION

ENG

YAMAHA WR400F (1999) - ENG - 1

KICK AXLE AND SHIFT SHAFT

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 1

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 2

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 3

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 4

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 5

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 6

EC4B5302

Kick axle assembly

1.Install:

.Kick gear ①
Ratchet wheel ②

NOTE:

Align the punched mark ⑧ on the ratchet wheel with the punched mark ⑥ on the kick axle.

  1. Install:

Torsion spring ①

To kick axle ②.

NOTE:

Make sure the stopper 已 of the torsion spring fits into the hole 已 on the kick axle.

  1. Install:

Spring guide ①

NOTE:

Slide the spring guide into the kick axle, make sure the groove ⑧ in the spring guide fits on the stopper of the torsion spring.

4.Install:

.Kick axle assembly ①
Plain washer ②

NOTE:

  • Apply the engine oil on the kick axle.
  • Slide the kick axle assembly into the crank-case, make sure the kick axle stopper (a) fit into their home position (b).

  • Hook:

Torsion spring ①

NOTE:

Turn the torsion spring clockwise and hook into the proper hole 已 in the crankcase.

AXE DE DEMARREUR AU PIED ET ARBRE DE SELECTEUR KICKSTARTERWELLE UND SCHALTWELLE EJE DEL PEDAL Y EJE DE SELECTION

KICK AXLE AND SHIFT SHAFT

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 1

YAMAHA WR400F (1999) - KICK AXLE AND SHIFT SHAFT - 2

EC4C5412

Kick idle gear

1.Install:

.Kick idle gear ①
Plain 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.

Extent of removal: ① CDI magneto removal

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalSeat and CDIMAGNETOREMOVAL fuel tank Refer to "SEAT, FUEL TANK AND SIDE Bolt [radiator (left)] Disconnect the CDI magneto lead.SIDE COVERS" section. Refer to "RADIATOR" section.
11 Shift pedal 1 2 Crankcase cover (left) 1 3 Gasket 1 4 Dowel pin 2 5 Nut (rotor) 1 Use special tool. 6 Rotor 1 7 Stator 1 8 Woodruff keyRefer to "REMOVAL POINTS".

MAGNETO CDI

YAMAHA WR400F (1999) - MAGNETO CDI - 1

Install three bolts ③ of the proper size, as shown in illustration.

EC4L4000

INSPECTION

EC4L4101

CDImagneto

  1. Inspect:

Rotor inner surface @
- Stator outer surface ⑤

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.

EC4L5000

ASSEMBLY AND INSTALLATION

EC4L5181

CDImagneto

1.Install:

  • Stator ①
    Bolt (stator) ②

10Nm(1.0m·kg,7.2ft·lb)

  1. Monter:

  2. Stator ①
    Boulon (stator) ②

10Nm (1,0m· kg,7,2ft· lb)

Scheibenfeder

  1. Kontrollieren:

Scheibenfeder ①

Clean the tapered portions of the crankshaft and rotor.
- When installing the woodruff key, make sure that its flat surface 已 is in parallel with the crankshaft center line 已 .
- When installing the rotor, align the keyway © of the rotor with the woodruff key.

YAMAHA WR400F (1999) - Scheibenfeder - 1

  1. Install:

Plain washer
.Nut (rotor) ①

YAMAHA WR400F (1999) - Scheibenfeder - 2

48Nm (4.8m· kg,35ft· lb)

Use the rotor holding tool ②.

YAMAHA WR400F (1999) - Scheibenfeder - 3

YAMAHA WR400F (1999) - Scheibenfeder - 4

  1. Connect:

CDImagneto lead

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

YAMAHA WR400F (1999) - Scheibenfeder - 5

  1. Install:

Gasket [crankcase cover (left)]
Crankcase cover (left) ①
Hose holder (cylinder head breather hose) ②
- Screw [crankcase cover (left)]

YAMAHA WR400F (1999) - Scheibenfeder - 6

10Nm(1.0m·kg,7.2ft·lb)

NOTE:

Tighten the screws in stage, using a crisscross pattern.

2. Monter:

-Shift pedal ①
Bolt (shift pedal)

NOTE:

When installing the shift pedal onto the shift shaft, be sure that the center of the shift pedal is 2mm above the top of the footrest.

  1. Monter:
Extent of removal Order Part Name Q'ty Remarks
Preparation for removalHold theEngine REMOVALmachine by placing thesuitable stand under the frame.Seat and fuel tank Refer to "SEAT, FUEL TANK AND SIDECOVERS" section.Carburetor Refer to "CARBURETOR" section.Exhaust pipe and silencerClutch cable Disconnect at engine side.Decompression cable and guide DiRadiator Refer to "RADIATOR" section.Shift pedal Refer to "CDI MAGNETO" section.Cylinder head breather hose and oil tank breather hoseDrain the engine oil Refer to "ENGINE OIL" section in the CHAPTER 3.

DEPOSE DU MOTEUR

YAMAHA WR400F (1999) - NOTE: - 1
Extent of removal: ① Engine removal

Extent of removal Order Part name Q'ty Remarks
11 Engine skidplate 12 Neutral switch 13 Engine oil hose 24 Chain cover 16 Lock washer 17 Drive sprocket 18 Clip 19 Bolt (brake pedal) 110 Brake pedal 111 Engine upper bracket (right) 12 Engine upper bracket (left) 13 Engine lower bracket 14 Engine mounting bolt 15 Pivot shaft 16 Engine1Refer to "REMOVAL POINTS".5 Nut (drive sprocket) 1
1Refer to "REMOVAL POINTS".5 Nut (drive sprocket) 1
  1. Remove:

  2. Nut (drive sprocket) ①
    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

ASSEMBLY AND INSTALLATION

EC4M5160

Engine installation

1.Install:

Engine ①

Install the engine from right side.

.Pivot shaft ②

YAMAHA WR400F (1999) - Engine installation - 1

85Nm(8.5m·kg,61ft·lb)

Engine mounting bolt (lower) ③

YAMAHA WR400F (1999) - Engine installation - 2

69Nm(6.9m·kg,50ft·lb)

Engine lower bracket ④

  • Bolt (engine bracket) ⑤

YAMAHA WR400F (1999) - Engine installation - 3

34Nm(3.4m·kg,24ft·lb)

Engine mounting bolt (front) ⑥

YAMAHA WR400F (1999) - Engine installation - 4

69Nm(6.9m·kg,50ft·lb)

Engine upper bracket (right) ⑦

Engine upper bracket (left) ⑧

Bolt (engine bracket) ⑨

YAMAHA WR400F (1999) - Engine installation - 5

34 Nm (3.4 m·kg, 24 ft·lb)

Engine mounting bolt (upper) 10

YAMAHA WR400F (1999) - Engine installation - 6

55Nm(5.5m·kg,40ft·lb)

EC4M5211

Brake pedal

1.Install:

Spring

  • Brake pedal ①

-O-ring ②

YAMAHA WR400F (1999) - Brake pedal - 1

Bolt (brake pedal) ③

YAMAHA WR400F (1999) - Brake pedal - 2

19Nm(1.9m·kg,13ft·lb)

Clip ④

NOTE:

  • Apply the lithium soap base grease on the bolt, O-rings and brake pedal bracket.
    Install the clip with its stopper portion 当 facing inward.

YAMAHA WR400F (1999) - NOTE: - 1

EC4M5331

Drive sprocket

  1. Install:

  2. Drive sprocket ①

  3. Drive chain ②

NOTE:

Install the drive sprocket together with the drive chain.

ASSEMBLAGE ET MONTAGE

Montage du moteur

  1. Monter:

Moteur ①

34Nm(3,4m·kg,24ft·lb)

34Nm(3,4m·kg,24ft·lb)

Tighten the nut while applying the rear brake.

  1. Bend the lock washer tab to lock the nut.

  2. Install:

Chain guide
Chain cover ①
Bolt (chain cover) ②

8Nm(0.8m·kg,5.8ft·lb)

  1. Install:

Engine oil hose ①
Bolt (engine oil hose) ②

10Nm(1.0m·kg,7.2ft·lb

  1. Install:

Spring ①
Pin ②
- Neutral switch ③
- Bolt (neutral switch) ④

4Nm(0.4m·kg,2.9ft·lb)

2. Monter:

CRANKCASE AND CRANKSHAFT

CRANKCASE AND CRANKSHAFT

YAMAHA WR400F (1999) - CRANKCASE AND CRANKSHAFT - 1

Extent of removal: ① Crankcase separation ② Crankcase removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalEngineCRANKCASE SEPARATIONRefer to "ENGINE REMOVAL" section.Piston Refer to "CYLINDER AND PISTON"Balancer Refer to "BALANCER" section.Kick axle assemblySegmentStator Refer to "CDI MAGNETO" section.sec-tion.Refer to "KICK AXLE AND SHIFTSHAFT" section.
121 Timing chain guide (rear) 12 Timing chain 13 Bolt (40 mm) 34 Bolt (50 mm) 45 Bolt (60 mm) 26 Bolt (75 mm) 37 Hose guide 18 Clutch cable holder9 Crankcase (right)10 Crankcase (left)Use special tool.Refer to "REMOVAL POINTS".
Extent of removal Order Part name Q'ty Remarks
11 Oi strainer 1 delivery pipe 1 Crankshaft 1 Use special tool.Refer to “REMOVAL POINTS”.

CARTER ET VILEBREQUIN KURBELGEHAUSE UND KURBELWELLE CARTER Y CIGUENAL

YAMAHA WR400F (1999) - CARTER ET VILEBREQUIN KURBELGEHAUSE UND KURBELWELLE CARTER Y CIGUENAL - 1

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalTransmissionShift cam and shift forkRefer to “TRANSMISSION, SHIFT CAMAND SHIFT FORK” section.
1 Oil seal 32 Bearing 10

ROULEMENTS DE CARTER

Crankcase (right)
Crankcase (left)

Separation steps:

  • Remove the crankcase bolts, hose guide and clutch cable holder.

NOTE:

Loosen each bolt 1/4 of a turn at a time and after all the bolts are loosened, remove them.

  • Remove the crankcase (right).

NOTE:

  • For this removal, slits in the crankcase.
  • As pressure is applied, alternately tap on the transmission shafts, shift cam and crankshaft.

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:

CRANKCASE AND CRANKSHAFT

YAMAHA WR400F (1999) - CRANKCASE AND CRANKSHAFT - 1

YAMAHA WR400F (1999) - CRANKCASE AND CRANKSHAFT - 2

EC4N3300

Crankshaft

  1. Remove:

Crankshaft ①

Use the crankcase separating tool ② and crankcase separating bolt ③

YAMAHA WR400F (1999) - Crankshaft - 1

Crankcase separating tool:

YU-01135-A/90890-01135

Crankcase separating bolt:

YM-01305/90890-01305

CAUTION:

Do not use a hammer to drive out the crankshaft.

YAMAHA WR400F (1999) - CAUTION: - 1

EC4N3401

Crankshaft bearing

  1. Remove:

Bearing stopper
Bearing ①

NOTE:

  • Remove the bearing from the crankcase by pressing its inner race as shown in A.
  • If the bearing is removed together with the crankshaft, remove the bearing using a general bearing puller ② as shown in B.
  • Do not use the removed bearing.

YAMAHA WR400F (1999) - NOTE: - 1

YAMAHA WR400F (1999) - NOTE: - 2

INSPECTION

Timing chain and timing chain guide

  1. Inspect:

  2. Timing chain

Cracks/stiff Replace the timing chain and camshaft sprocket as a set.

  1. Inspect:

  2. Timing chain guide

Wear/damage Replace.

Vilebrequin

  1. Déposer:

Vilebreguin ①

  1. Inspect:

  2. Contacting surface @

Scratches Replace.

Engine mounting boss 6, crankcase

Cracks/damage Replace.

  1. Inspect:

Bearing

Rotate inner race with a finger.

Rough spot/seizure Replace.

  1. Inspect:

Oil seal

Wear/damage Replace.

EC4N4201

Crankshaft

1.Measure:

Run-out limit @
Small end free play limit 6
Connecting rod big end side clearance
Crank width Out of specification Replace

Use the dial gauge and a thickness gauge.

Dial gauge and stand: YU-03097/90890-01252
Standard <Limit>
Run-out 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)-
Crack width:61.95 ~ 62.00 mm (2.439 ~ 2.441 in)-

Carter

  1. Controller:

Surface de contact @

Rayures Changer.

Oil delivery pipe holes ①

Clogged Blow out with compressed air.

EC4N5000

ASSEMBLY AND INSTALLATION

EC4N5300

Crankshaft bearing

  1. Install:

Bearing

YAMAHA WR400F (1999) - Crankshaft bearing - 1

Bearing stopper
Screw (bearing stopper)

YAMAHA WR400F (1999) - Crankshaft bearing - 2

To crankcase (left and right).

YAMAHA WR400F (1999) - Crankshaft bearing - 3

YAMAHA WR400F (1999) - Crankshaft bearing - 4

YAMAHA WR400F (1999) - Crankshaft bearing - 5

NOTE:

Install the bearing by pressing its outer race parallel.

EC4N5223

Crankshaft

  1. Install:

Crankshaft ①

Use the crankshaft installing tool ②, ③,

④,⑤

YAMAHA WR400F (1999) - Crankshaft - 1

Crankshaft installing tool:

Pot ②:

YU-90050/90890-01274

Bolt ③:

YU-90050/90890-01275

Adapter ④:

YU-90062/90890-01277

Spacer ⑤:

YM-91044/90890-04081

For USA and CDN
Except for USA and CDN

Carter d'huile

  1. Contrôler:

Carter d'huile

Endommagement Remplacer.

Ölsieb

  1. Kontrollieren:

Ölsieb

CRANKCASE AND CRANKSHAFT

YAMAHA WR400F (1999) - CRANKCASE AND CRANKSHAFT - 1

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.

YAMAHA WR400F (1999) - NOTE: - 1

YAMAHA WR400F (1999) - NOTE: - 2

YAMAHA WR400F (1999) - NOTE: - 3

CAUTION:

Do not use a hammer to drive in the crankshaft.

  1. Check:

  2. Shifter operation
    Transmission operation

Unsmooth operation Repair.

  1. Install:

. Oil strainer ①
Bolt (oil strainer) ②

10 Nm (1.0 m·kg, 7.2 ft·lb)

  1. Apply:

Sealant

On the crankcase (right) ①.

YAMAHA WR400F (1999) - CAUTION: - 1

Quick gasket:

ACC-11001-05-01

Yamaha bond No. 1215:

90890-85505

NOTE:

Clean the contacting surface of crankcase (left and right) before applying the sealant.

N.B.:

Dowel pin ①
O-ring ② New
Crankcase (right)

To crankcase (left).

NOTE:

  • Fit the crankcase (right) onto the crankcase (left). Tap lightly on the case with soft hammer.
  • When installing the crankcase, the connecting rod should be positioned at TDC (top dead center).

  • Tighten:

-Hose guide ①
- Clutch cable holder ②
Bolt (crankcase)

12Nm(1.2m·kg,8.7ft·lb)

NOTE:

Tighten the crankcase tightening bolts in stage, using a crisscross pattern.

  1. Install:

Oil delivery pipe
.O-ring New
- Bolt (oil delivery pipe)

  1. Install:

  2. Timing chain

  3. Timing chain guide (rear)
    Plate washer
  4. Bolt (timing chain guide)

10Nm(1.0m·kg,7.2ft·lb)

  1. Remove:

Sealant

Forced out on the cylinder mating surface.

  1. Apply:

Engine oil

To the crank pin, bearing and oil delivery hole.

  1. Check:

  2. Crankshaft and transmission operation. Unsmooth operation Repair.

  3. Monter:

Goujon ①

  • Joint torique ②

New

Demi-carter (droit)

TRANSMISSION, SHIFT CAM AND SHIFT FORK

TRANSMISSION, SHIFT CAM AND SHIFT FORK

YAMAHA WR400F (1999) - TRANSMISSION, SHIFT CAM AND SHIFT FORK - 1

Extent of removal: ① Shift fork, shift cam, main axle and drive axle removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalEngine Refer to "ENGINE REMOVAL" section. Separate the crankcase. Refer to "CRANKCASE AND CRANK-SHAFT" section.
11 Shift fork 1 1 2 Shift fork 2 1 3 Shift fork 3 1 4 Shift cam 1 5 Main axle 1 6 Drive axle 1 71Refer to "REMOVAL POINTS".

BOITE A VITESSES, TAMBOUR ET FOURCHETTE DE SELECTION

BOITE A VITESSES, TAMBOUR, FOURCHETTE DE SELECTION ET VILEBREQIN

Shift fork, shaft cam and transmission

  1. Remove:

Shift forks
Shift cam
Main axle
- Drive axle

NOTE:

  • Tap lightly on the transmission drive axle and shift cam with a soft hammer to remove.
  • Remove assembly carefully. Note the position of each part. Pay particular attention to the location and direction of shift forks.

YAMAHA WR400F (1999) - NOTE: - 1

EC4H4000

INSPECTION

EC4H4200

Gears

  1. Inspect:

Matching dog a
Gear teeth ⑤
Shift fork groove ©

Wear/damage Replace.

YAMAHA WR400F (1999) - Gears - 1

  1. Check:

Gears movement

Unsmooth movement Repair or replace.

YAMAHA WR400F (1999) - Gears - 2

EC4H4600

Bearing

  1. Inspect:

Bearing ①

Rotate inner race with a finger.

Rough spot/seizure Replace.

POINTS DE DEPOSE

For a malfunctioning shift fork, replace not only the shift fork itself but the two gears each adjacent to the shift fork.

EC4H5212

Transmission

1.Install:

  • 5th pinion gear (25T) ①
  • 3rd pinion gear (16T) ②
    Collar ③
    4th pinion gear (20T) ④
  • 2nd pinion gear (15T) 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.

.2nd wheel gear (26T) ①
.4th wheel gear (21T) ②
- 3rd wheel gear (21T) ③
- 5th wheel gear (21T) ④
.1st wheel gear (29T) ⑤
-O-ring ⑥
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.

  • Install:

Plain washer ①
Circlip ② New

NOTE:

  • Be sure the circlip sharp-edged corner 已 is positioned opposite side to the plain washer and gear 已 .
  • Be sure the circlip end © is positioned at axle spline groove @.

  • Install:

. Spacer ①

NOTE:

  • Apply the lithium soap base grease on the oil seal lip.
  • When installing the spacer into the crankcase, pay careful attention to the crankcase oil seal lip.

2. Monter:

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.

  • Install:

Transmission assembly ①

To crankcase (left) ②.

NOTE:

Apply the engine oil on the bearings and guide bars.

  1. Check:

  2. Shifter operation
    Transmission operation

Unsmooth operation Repair.

5. Monter:

① Front wheel removal

② Wheel bearing removal

③ Break disc removal

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalFRONT WHEEL REMOVALHold the machine by placing the suitable stand under the engine.
131 Trip meter cable 12 Hose cover 13 Bolt (axle holder) 4 Only loosening.4 Nut (front wheel axle) 15 Front wheel axle 16 Front wheel 17 Trip meter gear unit 18 Collar 19 Oil seal 11 Bearing 2 Refer to "REMOVAL POINTS".11 Brake disk1 WarningSupport the machine securely so there is no danger of it falling over.

PARTIE CYCLE

ROUE AVANT ET ROUE ARRIERE

ROUE AVANT

① Rear wheel removal
③ Break disc removal

② Wheel bearing removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalREAR WHEEL REMOVALHold the machine by placing the suitable stand under the engine.
13231 Nut (rear wheel axle) 12 Rear wheel axle 13 Chain puller 24 Rear wheel 1 Refer to "REMOVAL POINTS".5 Collar 26 Driven sprocket 17 Oil seal 28 Circlip 19 Bearing 2 Refer to "REMOVAL POINTS".10 Brake disk1WARNINGSupport the machine securely so there is no danger of it falling over.

ROUE AVANT ET ROUE ARRIERE

VORDER- UND HINTERRAD

RUEDA DELANTERA Y RUEDA TRASERA

YAMAHA WR400F (1999) - RUEDA DELANTERA Y RUEDA TRASERA - 1

ROUEARRIERE

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 WR400F (1999) - 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 arriere

  1. Déposser:

Roue ①

N.B.:

  1. Measure:

  2. Wheel axle bends Out of specification Replace. Use the dial gauge ①.

YAMAHA WR400F (1999) - Roue arriere - 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 WR400F (1999) - Roue arriere - 2

WARNING

Do not attempt to straighten a bent axle.

YAMAHA WR400F (1999) - WARNING - 1

EC514302

Brakedisc

  1. Measure:

  2. Brake disc deflection Use the dial gauge ① . Out of specification Inspect wheel runout. If wheel runout is in good condition, replace the brake disc.

YAMAHA WR400F (1999) - Brakedisc - 1

Disc deflection limit: 0.15 mm (0.006 in)

  1. Measure:

  2. Brake disc thickness @ Out of limit Replace.

Disc wear limit:
Standard <Limit>
Front3.0 mm (0.12 in) 2.5 mm (0.10 in)
Rear4.0 mm (0.16 in) 3.5 mm (0.14 in)

ROUE AVANT ET ROU ARRIERE VORDER- UND HINTERRAD RUEDA DELANTERA Y RUEDA TRASERA

YAMAHA WR400F (1999) - ROUE AVANT ET ROU ARRIERE VORDER- UND HINTERRAD RUEDA DELANTERA Y RUEDA TRASERA - 1

Axe de roue

ASSEMBLY AND INSTALLATION

EC595100

Front wheel

1.Install:

  • Bearing (left) ①
  • Spacer ②
  • Bearing (right) ③
  • 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:

-Brake disc ①
Bolt (brake disc) ②

YAMAHA WR400F (1999) - CAUTION: - 1

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:

.Wheel

NOTE:

Install the brake disc between the brake pads correctly.
Make sure that the projections 已 in the trip meter gear unit fits over the stopper ⑥ on the front fork outer tube.

REMONTAGE ET MONTAGE

Roue avant

  1. Monter:

Apply the lithium soap base grease on the wheel axle.

  1. Install:

  2. Nut (wheel axle) ①

105Nm(10.5m·kg,75ft·lb)

  1. Tighten:

  2. 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.

  1. Install:

  2. Brake hose ①

10Nm(1.0m·kg,7.2ft·lb)

To brake hose holder ②.

NOTE:

Before tightening the bolt (brake hose holder), pass the brake hose in front of the axle boss a, then fit it into the hose groove b so that the brake hose does not contact the nut (wheel axle).

ROUE AVANT ET ROU ARRIERE VORDER- UND HINTERRAD RUEDA DELANTERA Y RUEDA TRASERA

5. Monter:

-Axe deroue ①

N.B.:

23Nm(2,3m·kg,17ft·lb)

N.B.:

23Nm(2,3m·kg,17ft·lb)

NOTA:

-Hose cover ①
Plain washer ②
Bolt [hose cover (M8)] ③

16Nm(1.6m·kg,11ft·lb)

Bolt [hose cover (M6)] ④

7Nm (0.7m· kg,5.1ft· lb)

10.Install:

  • Trip meter cable ①

EC525112

Rear wheel

  1. Install:

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.

9. Monter:

Tighten the bolts in stage, using a crisscross pattern.

3.Install:

  • Driven sprocket ①
  • Bolt (driven sprocket) ②
    Plain washer (driven sprocket) ③
    Nut (driven sprocket) ④

42Nm (4.2m· kg,30ft· lb)

NOTE:

Tighten the nuts in stage, using a crisscross pattern.

4.Install:

Collar ①

NOTE:

Install the collar marked "L" on the driven sprocket side and the collar marked "R" on the brake disc side.

  1. Install:

.Wheel

NOTE:

Install the brake disc ① between the brake pads ② correctly.

  1. Install:

  2. Drive chain ①

NOTE:

Push the wheel ② forward and install the drive chain.

2. Monter:

Install the chain puller (left), and insert the wheel axle from left side.
- Apply the lithium soap base grease on the wheel axle.

  1. Install:

Chain puller ①
Plain washer ②
.Nut (wheel axle) ③

NOTE:

Temporarily tighten the nut (wheel axle) at this point.

  1. Adjust:

  2. Drive chain slack @

YAMAHA WR400F (1999) - Monter: - 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

125Nm(12.5m·kg,90ft·lb)

.Locknut ②

ROUE AVANT ET ROUE ARRIERE

VORDER- UND HINTERRAD

RUEDA DELANTERA Y RUEDA TRASERA

YAMAHA WR400F (1999) - RUEDA DELANTERA Y RUEDA TRASERA - 1

7. Monter:

YAMAHA WR400F (1999) - Monter: - 1
Extent of removal: ① Brake hose removal ② Caliper removal
③ Master cylinder removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalFRONT BRAKE REMOVALHold the machine by placing the suitable stand under the engine.Drain the brake fluid.
1 2 3 4 5 6 7 8 9 10 Master cylinder bracket 1 11 Master cylinder 11 Hose cover 12 Brake hose holder 13 Bolt (brake hose holder) 2 Only loosening.4 Union bolt 25 Brake hose 16 Pad pin plug 1 Remove when loosening the pad pin.7 Pad pin 1 Loosen when disassembling the caliper.8 Caliper 19 Brake lever 110 Master cylinder bracket 111 Master cylinder 1

FREIN AVANT ET FREIN ARRIERE

VORDER- UND HINTERRADBREMSE

FRENO DELANTERO Y FRENO TRASERO

YAMAHA WR400F (1999) - FRENO DELANTERO Y FRENO TRASERO - 1

FREIN AVANT ET FREIN ARRIERE

FREIN AVANT

YAMAHA WR400F (1999) - FREIN AVANT - 1
Extent of removal: ① Caliper removal ② Brake hose removal
③ Master cylinder removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalREAR BRAKE REMOVALHold the machine by placing the suitable stand under the engine.Rear wheel Refer to "FRONT WHEEL AND REAR WHEEL" section.POINTS".
1 Pad pin plug 1 Remove when loosening the pad pin.2 Pad pin 1 Loosen when disassembling the caliper.3 Caliper 14 Brake hose holder 25 Union bolt 26 Brake hose 17 Brake pedal8 Reservoir tank9 Reservoir hose10 Master cylinder1警告Support the machine securely so there is no danger of it falling over.

FREIN AVANT ET FREIN ARRIERE

VORDER- UND HINTERRADBREMSE

FRENO DELANTERO Y FRENO TRASERO

CHAS

YAMAHA WR400F (1999) - CHAS - 1

FREIN ARRIERE

YAMAHA WR400F (1999) - FREIN ARRIERE - 1
A Front
Rear
Extent of removal:
① Front caliper disassembly
② Rear caliper disassembly

Extent of removal Order Part Name Q'ty Remarks
12CALIPER DISASSEMBLY A B ① ② ③ ④ Caliper piston 2 1 Refer to "REMOVAL POINTS". ⑤ ⑥Dust seal Piston seal

DEMONTAGE DE L'ETRIER

A Avant
[8] Arrière

YAMAHA WR400F (1999) - DEMONTAGE DE L'ETRIER - 1
A Front
Rear
Extent of removal:
① Front master cylinder disassembly
② Rear master cylinder disassembly

Extent of removal Order Part name Q'ty Remarks
1 2 ②↑MASTER CYLINDER DISAS-SEMBLY ① Master cylinder cap 1 ② Diaphragm 1 ③ Locknut 1 ④ Master cylinder boot 1 ⑤ Circlip 1 Use a long nose circlip pliers. ⑥ Plain washer 1 ⑦ Push rod 1 ⑧ Master cylinder kit1

DEMONTAGE DU MAITRE-CYLINDRE

A Avant
B Arriere

  • Master cylinder cap ①
    [Rear]
  • Master cylinder guard ①
  • Reservoir tank cap ②

NOTE:

Do not remove the diaphragm.

A Front
Rear

  1. Connect the transparent hose ① to the bleed screw ② and place a suitable container under its end.

A Front

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.

EC533301

Caliper piston

  1. Remove:

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 caliper to lock one caliper.
  • Carefully force the piston out of the caliper cylinder with compressed air.

A Front
Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

POINTS DE DEPOSE

Liquide de frein

  1. Déposser:

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
Rear

EC5A4000

INSPECTION

EC534112

Master cylinder

  1. Inspect:

  2. Master cylinder inner surface @

Wear/scratches Replace master cylinder assembly.

Stains Clean.

WARNING

Use only new brake fluid.

A Front
Rear

  1. Inspect:

Diaphragm ①

Crack/damage Replace.

A Front
Rear

  1. Inspect:

  2. Master cylinder piston ①

  3. Master cylinder cup ②

Wear/damage/score marks Replace master cylinder kit.

A Front
Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

Kit de jointe piston

  1. Déposser:

Joint antipoussiere ①
Joint de piston ②

N.B.:

  1. Inspect:

  2. Caliper cylinder inner surface @ Wear/score marks Replace caliper assembly.

A Front
Rear

  1. Inspect:

  2. Caliper piston ① Wear/score marks Replace caliper piston assembly.

WARNING

Replace the piston seals and dust seals ② whenever a caliper is disassembled.

EC534301

Brake hose

  1. Inspect:

  2. 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.

EC5A5800

Caliper piston

  1. Clean:

Caliper
Piston seal
Dust seal
- Caliper piston Clean them with brake fluid.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

Etrier

Always use new piston seals and dust seals.

NOTE: Fit the piston seals and dust seals onto the slot on caliper correctly.

A Front
Rear

  1. Install:

-Caliper piston ①

NOTE:

Apply the brake fluid on the piston wall.

CAUTION:

For the front caliper, install the piston with its depressed side a facing the caliper. For the rear caliper, install the piston with its shallow depressed side b facing the caliper.
. Never force to insert.

A Front
Rear

EC5A5700

Front caliper

1.Install:

  • Pad support ①
  • Brake pad ②
  • Pad pin ③

NOTE:

Install the brake pads with their projections into the caliper recesses
- Temporarily tighten the pad pin at this point.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

  1. Monter:

  2. Joint de piston ①

New

Dichtring ①

New

stalar:

  • Retén del pistón ①

New

Joint antipoussier

Staubschutzring ②

New

Guardapolvos ②

New

AVERTISSEMENT

Always use new copper washers.

CAUTION:

Install the brake hose so that its pipe portion ③ directs as show and lightly touches the projection 包 on the caliper.

  1. Install:

  2. Brake hose holder ①
    -Caliper ②
    Bolt (caliper) ③

23Nm(2.3m·kg,17ft·lb)

NOTE: Fit the brake hose holder cut @ over the projection ⑥ on the front fork and clamp the brake hose.

  1. Tighten:

  2. Pad pin ④

18Nm(1.8m·kg,13ft·lb)

  1. Install:

  2. Pad pin plug ⑤

3Nm (0.3m· kg,2.2ft· lb)

YAMAHA WR400F (1999) - CAUTION: - 1

EC5A5100

Rear caliper

  1. Install:

  2. Pad support ①

  3. Brake pad ②
  4. Pad pin ③

NOTE:

Install the brake pads with their projections 已 into the caliper recesses
- Temporarily tighten the pad pin at this point.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

YAMAHA WR400F (1999) - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO - 1

2. Monter:

23Nm(2,3m·kg,17ft·lb)

N.B.:

  • Brake hose ②
    .Union bolt ③

30Nm(3.0m·kg,22ft·lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose to the caliper with the paint ⑧ on the pipe facing the caliper and with the pipe contacting the caliper projection ⑥

  1. Install:

-Caliper ①
Rear wheel ②

Refer to "FRONT WHEEL AND REAR WHEEL" section.

  1. Tighten:

  2. Pad pin ③

18Nm(1.8m·kg,13ft·lb)

  1. Install:

  2. Pad pin plug ④

3Nm(0.3m·kg,2.2ft·lb)

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

YAMAHA WR400F (1999) - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO - 1

2. Monter:

Protection de disque ①
Boulon (protection) ②

7Nm(0,7m·kg,5,1ft·lb)

2. Montieren:

  1. Clean:

  2. Master cylinder

  3. Master cylinder kit

Clean them with brake fluid.

YAMAHA WR400F (1999) - Montieren: - 1

YAMAHA WR400F (1999) - Montieren: - 2

YAMAHA WR400F (1999) - Montieren: - 3

2.Install:

  • Master cylinder cup (primary) ①
  • Master cylinder cup (secondary) ②

To master cylinder piston ③.

NOTE:

Apply the brake fluid on the master cylinder
CUP

WARNING

After installing, cylinder cup should be installed as shown direction. Wrong installation cause improper brake performance.

A Front
Rear

  1. Install:

Spring ①

To master cylinder piston ②.

NOTE:

Install the spring at the smaller diameter side.

A Front
Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

  • Master cylinder boot ⑤

Locknut ⑥ To master cylinder ⑦

[Rear]

  • Master cylinder kit ①

  • Push rod ②

Circlip ③

  • Master cylinder boot ④

Locknut ⑤

To master cylinder ④.

NOTE:

  • Apply the brake fluid on the 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
Rear

YAMAHA WR400F (1999) - NOTE: - 1

Front master cylinder

1.Install:

  • Master cylinder ①
  • Master cylinder bracket ②
  • Bolt (master cylinder bracket) ③

9Nm (0.9m· kg,6.5ft· lb)

NOTE:

Install the bracket so that the arrow mark @ face upward.
- First tighten the bolts on the upper side of the master cylinder bracket, and then tighten the bolts on the lower side.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

4. Monter:

[Avant]

Make sure the circlip is installed into the groove @ of the push rod.
After installing, check the brake lever position. Refer to "FRONT BRAKE ADJUSTMENT" section in the CHAPTER 3.

YAMAHA WR400F (1999) - [Avant] - 1

YAMAHA WR400F (1999) - [Avant] - 2

EC5A5400

Rear master cylinder

1.Install:

  • Reservoir hose ①
  • Reservoir tank ②

  • Install:

  • Master cylinder ①
    Bolt (master cylinder) ②

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

YAMAHA WR400F (1999) - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO - 1

2. Monter:

  • Apply the lithium soap base grease on the bolt, O-ring and brake pedal bracket.
    Install the clip with its stopper portion @ facing inward.

YAMAHA WR400F (1999) - Monter: - 1

  1. Install:

Pin ①
Plain washer ②
Cotter pin ③ New

NOTE: After installing, check the brake pedal height. Refer to "REAR BRAKE ADJUSTMENT" section in the CHAPTER 3.

YAMAHA WR400F (1999) - Monter: - 2

Front brake hose

  1. Install:

  2. Brake hose ①

10Nm(1.0m·kg,7.2ft·lb)

To brake hose holder ②.

NOTE: Before tightening the bolt (brake hose holder), pass the brake hose in front of the axle boss 已 then fit it into the hose groove ⑥ so that the brake hose does not contact the nut (wheel axle).

  1. Install:

Hose cover ①
Plain washer ②
Bolt [hose cover (M8)] ③

16Nm(1.6m·kg,11ft·lb)

  • Bolt [hose cover (M6)] ④

7Nm(0.7m·kg,5.1ft·lb)

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

3. Monter:

  • Ressort ①
    Pedale de frein ②
    Joint torque ③ New
    Boulon (pedale de frein) ④
  1. Pass the brake hose through the cable guide ① then through the guide 已 on the protector ②

  2. Install:

Copper washer ①

New

  • Brake hose ②

.Union bolt ③

30Nm (3.0m· kg,22ft· lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose so that it contacts the master cylinder projection ⑧ and that its bent portion ⑥ faces downward.

EC5A5500

Rear brake hose

  1. Install:

Copper washer ①

New

  • Brake hose ②

New

Copper washer ③

.Union bolt ④

30Nm(3.0m·kg,22ft·lb)

WARNING

Always use new copper washers.

CAUTION:

When installing the brake hose, first align the tooth ⑧ on the copper washer ① with the projection ⑥ on the master cylinder. Then, align the pipe portion on the end of the brake hose with the tooth ⑨ on the copper washer ① and tighten the union bolt.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

YAMAHA WR400F (1999) - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO - 1

  1. Faire passer la tuyau de frein dans le guide de cable ① ,puis dans le guide 包 sur le protecteur ②

  2. Den Bremsschlauch durch die Kabelführung ①, dann durch die Führung ② am Protektor ② leiten.

  3. Pase el tubo del freno a trovés de la guía del cable ① y después a trovés de la guía ② del protector ②.

4. Monter:

m = 311

Boulon-raccord ③

30Nm(3,0m·kg,22ft·lb)

AVERTISSEMENT

  1. Install:

  2. Brake hose holder ①
    Screw (brake hose holder) ②

4Nm (0.4m· kg,2.9ft· 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.

EC5A5600

Brake fluid

  1. Fill:

  2. Brake fluid

Until the fluid level reaches "LOWER" level line (包)

YAMAHA WR400F (1999) - Brake fluid - 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
Rear

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

YAMAHA WR400F (1999) - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO - 1

2. Monter:

  • Support de tuyau de frein (1)
  • Vis (support de tuyau de frein) ②

4Nm(0.4m·kg,2.9ft·lb)

ATTENTION:

Fluid at lower level Fill up.

Refer to "BRAKE FLUID LEVEL INSPECTION" section in the CHAPTER 3.

YAMAHA WR400F (1999) - ATTENTION: - 1

YAMAHA WR400F (1999) - ATTENTION: - 2

YAMAHA WR400F (1999) - ATTENTION: - 3

4. Install:

[Front]

Diaphragm
- Master cylinder cap ①
Screw (master cylinder cap) ②

2Nm(0.2m·kg,1.4ft·lb)

[Rear]

Diaphragm
- Reservoir tank cap ①
- Master cylinder guard

10Nm(1.0m·kg,7.2ft·lb)

CAUTION:

After installation, while pulling the lever in or pushing down on the pedal, check whether there is any brake fluid leaking where the union bolts are installed respectively at the master cylinder and caliper.

A Front
Rear

  1. Install: (rear brake only)

  2. Caliper protector ①
    Bolt (protector) ②

7Nm(0.7m·kg,5.1ft·lb)

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSE FRENO DELANTERO Y FRENO TRASERO

2. Purger l'air:

Extent of removal: ① Front fork removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalFRONT FORK REMOVALHold the machine by placing the suitable stand under the engine.Front wheel Refer to "FRONT WHEEL AND REARWHEEL" section.AND REARBRAKE section.
Front caliper Refer to "FRONT BRAKE Number plate
11 Protector 12 Brake hose holder 23 Pinch bolt (handle crown) 2 Only loosening.4 Cap bolt 1 Loosen when disassembling the front5 Pinch bolt (under bracket) 2 Only loosening.6 Front fork 1fork.

FOURCHE AVANT

YAMAHA WR400F (1999) - FOURCHE AVANT - 1
Extent of removal:
① Oil seal removal
② Damper rod removal

Extent of removal Order Part Name Q'ty Remarks
12FRONT FORK DISASSEMBLY ① Cap bolt 1 Refer to "REMOVAL POINTS". ② Fork spring 1 Drain the fork oil. ③ Dust seal 1 ⑤ Inner tube 1 ⑥ Outer tube 1 ⑦ Piston metal ⑧ Slide metal ⑨ Plain washer ⑩ Oil seal ⑪ Spring guide ⑫ Base valve ⑬ Damper rodRefer to "REMOVAL POINTS".④ Stop per ring

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 WR400F (1999) - CAUTION: - 1

YAMAHA WR400F (1999) - CAUTION: - 2

EC553000

REMOVAL POINTS

EC553150

Cap bolt

  1. Remove:

  2. Cap bolt ①

From the outer tube.

NOTE:

Before removing the front fork from the machine, loosen the cap bolt.

  1. Remove:

  2. 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 cap bolt.

REMARQUES CONCERNANT LA MANIPULATION

N.B.:

Using slotted-head screwdriver.

CAUTION:

Take care not to scratch the inner tube.

  1. Remove:
    -Innert tube ①

Oil seal removal steps:

  • Push in slowly @ the inner tube just before it bottoms out and then pull it back quickly ⑥.
  • 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 WR400F (1999) - NOTE: - 1

Damper rod holder: YM-1423/90890-01423

EC554000

INSPECTION

EC554100

Damper rod

  1. Inspect:

  2. 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

  1. Déposser:

Joint antipoussiere ①
Bagued'arret ②

Fork spring free length @

Out of specification Replace.

Fork spring free length:
Standard <Limit>
460 mm (18.1 in)455 mm (17.9 in)

EC554502

Inner tube

  1. Inspect:

  2. 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 WR400F (1999) - Inner tube - 1

NOTE:

The bending value is shown by one half of the dial gauge reading.

YAMAHA WR400F (1999) - NOTE: - 1

WARNING

Do not attempt to straighten a bent inner tube as this may dangerously weaken the tube.

EC554600

Outer tube

  1. Inspect:

  2. Outer tube ①

Score marks/wear/damage Replace.

Soupape de base

ASSEMBLY AND INSTALLATION

EC5551A0

Front fork assembly

  1. Wash the all parts in a clean solvent.

YAMAHA WR400F (1999) - Front fork assembly - 1

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 WR400F (1999) - CAUTION: - 1

  1. Install:

Copper washer ①

YAMAHA WR400F (1999) - CAUTION: - 2

. O-ring ②
. Base valve ③

To inner tube ④.

  1. Tighten:

  2. Base valve ①

YAMAHA WR400F (1999) - CAUTION: - 3

55Nm(5.5m·kg,40ft·lb)

NOTE:

  • Use a damper rod holder ② to lock the damper rod ③.
  • Apply the LOCTITE® on the base valve thread.

YAMAHA WR400F (1999) - NOTE: - 1

YAMAHA WR400F (1999) - NOTE: - 2

Damper rod holder: YM-1423/90890-01423

Bouchon de fourche

  1. Contrôler:

Boulon capuchon ①
Joint torque ②
- Vis de purgege d'air ③ - Usure/endommagement → Changer.

Verschlußschaubae

  1. Kontrollieren:

Install the spring guide with its cut ⑧ facing upward.
- With its thread ⑥ facing upward, fully finger tighten the locknut onto the damper rod.

  1. Install:

. Dust seal ①
- Stopper ring ②
. Oil seal ③ New
Plain 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 ④ 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.

  • Install:

. Piston metal ① New

NOTE:

Install the piston metal onto the slot on inner tube.

  1. Install:

  2. Outer tube ①

To inner tube ②.

5. Monter:

NOTE: Press the slide metal into the outer tube with fork seal driver ③.

YAMAHA WR400F (1999) - Monter: - 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 WR400F (1999) - Monter: - 2

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:

  1. Check:

  2. Inner tube smooth movement Tightness/binding/rough spots Repeat the steps 2 to 12.

14.Compress the front fork fully.

  1. Fill:

  2. Front fork oil

  3. Until outer tube top surface with recommended fork oil (1).

YAMAHA WR400F (1999) - Monter: - 1

Recommended oil: Suspension oil "01"

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 WR400F (1999) - CAUTION: - 1

YAMAHA WR400F (1999) - CAUTION: - 2

  1. After filling, pump the damper rod ① slowly up and down more than 10 times to distribute the fork oil.

  2. Fill:

  3. Front fork oil

  4. Until outer tube top surface with recommended fork oil once more.

  5. After filling, pump the outer tube ① slowly up and down (about 200mm (7.9 in) stroke) to distribute the fork oil once more.

NOTE: Be careful not to excessive full stroke. A stroke of 200mm (7.9 in) or more will cause air to enter. In this case, repeat the steps 15 to 18.

  1. Controller:

19.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 WR400F (1999) - NOTE: - 1

20.Measure:

. Oil level (left and right) @

Out of specification Adjust.

YAMAHA WR400F (1999) - NOTE: - 2

Standard oil level:

135 mm (5.31 in)

*125 mm (4.92 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.

Out of specification Turn into the locknut.

YAMAHA WR400F (1999) - WARNING - 1

Distance @: 20 mm (0.79 in) or more Between damper rod ① top and locknut ② top.

  1. Loosen:

  2. 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 cap bolt ④.

NOTE:

Install the cushion rubber with its smaller dia. end 包 facing the 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:

  • Cap bolt ① Fully tighten the cap bolt onto the damper rod by hand.

  • Mesurer:

Distance @

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 cap bolt with specified torque.

27.Install:

.Cap bolt ①

To outer tube.

NOTE:

Temporarily tighten the cap bolt.

28.Install:

  • Protector guide ①

EC5552A0

Installation

  1. Install:

  2. Front fork ①

NOTE:

  • Temporarily tighten the pinch bolts (under bracket).
  • Do not tighten the pinch bolts (handle crown) yet.

  • Tighten:

  • Cap bolt ①

30Nm(3.0m·kg,22ft·lb)

  1. Adjust:

  2. Front fork top end @

YAMAHA WR400F (1999) - Installation - 1

Front fork top end (standard) @:

5 mm (0.20 in)

*Zero mm (Zero in)

  • For EUROPE

  • Serrer:

-Bouchon de fourche (contré-crou) ①

29Nm (2,9m· kg,21ft· lb)

N.B.:

  • Pinch bolt (handle crown) ①

23Nm(2.3m·kg,17ft·lb)

Pinch bolt (under bracket) ②

20Nm (2.0m· kg,14ft· lb)

CAUTION:

Tighten the under bracket to specified torque. If torqued too much, it may cause the front fork to malfunction.

5. Install:

  • Brake hose holder ①
    -Caliper ②
    Bolt (caliper) ③

23 Nm (2.3 m·kg, 17 ft·lb)

NOTE:

Fit the brake hose holder cut ⑧ over the projection ⑥ on the front fork and clamp the brake hose.

6. Install:

  • Brake hose holder ①
    Bolt (brake hose holder) ②

10Nm(1.0m·kg,7.2ft·lb

  • Protector ③
    Bolt (protector) ④

10Nm(1.0m·kg,7.2ft·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 so that the brake hose does not contact the nut (wheel axle).

YAMAHA WR400F (1999) - Install: - 1

7. Adjust:

Rebound damping force

NOTE:

Turn in the damping adjuster ① finger-tight and then turn out to the originally set position.

  1. Serrer:

23Nm(2,3m·kg,17ft·lb)

23Nm(2,3m·kg,17ft·lb)

N.B.:

Extent of removal: ① Handlebar removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalHANDLEBAR REMOVAL Number plate
11 Decompression cable 1 Disconnect at 2 Decompression lever holder 1 3 Clutch cable 1 Disconnect at the lever 4 Clutch lever holder 1 5 "ENGINE STOP" button 1 6 Lights switch 1 7 Master cylinder 1 Refer to "REMOTE 8 Throttle cable cap 1 9 Throttle cable #2 (pushed) 1 Disconnect at the 10 Throttle cable #1 (pulled) 11 Grip (right) 12 Tube guide 13 Collar 14 Grip (left) 15 Handlebar holder (upper) 16 Handlebarthe lever side. side. POINTS". throttle side. Disconnect at the throttle side. Refer to "REMOTE POINTS". Refer to "REMOTE POINTS".

GUIDON

  1. Remove:

  2. Master cylinder bracket ①
    .Master cylinder ②

CAUTION:

  • Do not let the master cylinder hang on the brake hose.
  • Keep the master cylinder cap side horizontal to prevent air from coming in.

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.

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.

EC5B5000

ASSEMBLY AND INSTALLATION

  1. Install:

  2. Handlebar ①

  3. Handlebar holder ②
  4. Bolt (handlebar holder) ③

23Nm(2.3m·kg,17ft·lb)

NOTE:

The upper handlebar holder should be installed with the punched mark @ forward.
- First tighten the bolts on the front side of the handlebar holder, and then tighten the bolts on the rear side.

POINTS DE DEPOSE

Maitre-cylindre

  1. Déposser:

23Nm(2,3m·kg,17ft·lb)

N.B.:

23Nm(2,3m·kg,17ft·lb)

NOTA:

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 grip (left) to the handlebar so that the line 6 between the two arrow marks faces straight upward.

YAMAHA WR400F (1999) - Maitre-cylindre - 1

  1. Install:

Grip (right) 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 ⑧ with a lacquer thinner.

Install the grip to the tube guide so that the grip match mark ⑥ and tube guide slot ⑤ form the angle as shown.

YAMAHA WR400F (1999) - Maitre-cylindre - 2

  1. Install:

-Collar ①
- Throttle cables ②

To tube guide ③.

YAMAHA WR400F (1999) - Maitre-cylindre - 3

NOTE:

Apply the lithium soap base grease on the throttle cable end and tube guide cable winding portion.

2. Monter:

-Poignee (gauche) ①

  1. Install:

  2. Throttle cable cap ①
    Screw (throttle cable cap) ③

4Nm(0.4m·kg,2.9ft·lb)

Cover (throttle cable cap) ④

WARNING

After tightening the screws, check that the throttle grip ④ moves smoothly. If it does not, retighten the bolts for adjustment.

  1. Install:

  2. Master cylinder ①

  3. Master cylinder bracket ②
  4. Bolt (master cylinder bracket) ③

9Nm (0.9m· kg,6.5ft· lb)

NOTE:

Install the bracket so that the arrow mark @ faces upward.
- First tighten the bolt on the upper side of the master cylinder bracket, and then tighten the bolt on the lower side.

  1. Install:

-Lights switch ①

  1. Install:

  2. "ENGINE STOP" button ①

  3. Clutch lever holder ②
  4. Bolt (clutch lever holder) ③

4Nm (0.4m· kg,2.9ft· lb)

Decompressor lever holder ④
- Screw (decompressor lever holder) ⑤

4Nm (0.4m· kg,2.9ft· lb)

.Clamp ⑥

5. Monter:

The "ENGINE STOP" button, clutch lever holder and clamp should be installed according to the dimensions shown.
- Pass the "ENGINE STOP" button lead in the middle of the clutch holder.

9. Install:

  • Clutch cable ①

NOTE:

Apply the lithium soap base grease on the clutch cable end.

10. Adjust:

  • Clutch lever free play

Refer to "CLUTCH ADJUSTMENT" section in the CHAPTER 3.

11.Insert the end of the fuel breather hose ① into the hole of the steering shaft.

N.B.:

YAMAHA WR400F (1999) - N.B.: - 1
Extent of removal: ① Under bracket removal ② Bearing removal

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalHold the STEERING REMOVAL machine by placing the suitable stand under the engine. Number plate Handlebar Cable guide Front fenderWARNING Support the machine securely so there is no danger of it falling over. Refer to “HANDLEBAR” section.
1 21 Trip 1 2 Steering shaft nut 1 3 Front fork 2 Refer to “FRONT FORK” section. 4 Handle crown 1 5 Ring nut 1 Use special tool. 6 Under bracket 1 7 Ball race cover1Refer to “REMOVAL POINTS”.

DIRECTION

Ring nut wrench: YU-33975/90890-01403

WARNING

Support the steering shaft so that it may not fall down.

YAMAHA WR400F (1999) - WARNING - 1

EC563300

Bearing (lower)

  1. Remove:

Bearing (lower) ①

Use the floor chisel ②

CAUTION:

Take care not to damage the steering shaft thread.

YAMAHA WR400F (1999) - CAUTION: - 1

EC563400

Ball race

  1. Remove:

Ball race ①

Remove the ball race using long rod ② and the hammer.

YAMAHA WR400F (1999) - Ball race - 1

EC564000

INSPECTION

EC564200

Steering shaft

  1. Inspect:

  2. Steering shaft ①

Bend/damage Replace.

POINTS DE DEPOSE

Ecrou annulaire

Bearing and ball race

  1. Wash the bearings and ball races with a solvent.
  2. Inspect:

-Bearing ①
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 WR400F (1999) - Bearing and ball race - 1

EC565000

ASSEMBLY AND INSTALLATION

EC565112

Under bracket

  1. Install:

Bearing (lower) ①

NOTE:

Apply the lithium soap base grease on the dust seal lip and bearing inner circumference.

YAMAHA WR400F (1999) - Under bracket - 1

2.Install:

Ball race
Bearing (upper) ①
Ball race cover ②

NOTE:

Apply the lithium soap base grease on the bearing and ball race cover lip.

YAMAHA WR400F (1999) - Under bracket - 2

  1. Install:

-Underbracket ①

NOTE:

Apply the lithium soap base grease on the bearing and the portion 已 of the steering shaft.

Refer to "STEERING HEAD INSPECTION AND ADJUSTMENT" section in the CHAPTER 3.

  1. Check the steering shaft by turning it lock to lock. If there is any binding, remove the steering shaft assembly and inspect the steering bearings.
  2. Install:

Plain washer ①

  1. Install:

-Front fork ①
- Handle crown ②

NOTE:

  • Temporarily tighten the pinch bolts (under bracket).
  • Do not tighten the pinch bolts (handle crown) yet.

  • Install:

Plain washer ①
- Steering shaft nut ②

145Nm(14.5m·kg,105ft·lb)

4. Monter:

  1. After tightening the nut, check the steering for smooth movement. If not, adjust the steering by loosening the ring nut little by little.

  2. Adjust:

  3. Front fork top end @

YAMAHA WR400F (1999) - Monter: - 1

Front fork top end (standard) a: 5 mm (0.20 in) *Zero mm (Zero in)

  • For EUROPE

11.Tighten:

  • Pinch bolt (handle crown) ①

23Nm (2.3m· kg,17ft· lb)

Pinch bolt (under bracket) ②

20Nm(2.0m·kg,14ft·lb)

CAUTION:

Tighten the under bracket to specified torque. If torqued too much, it may cause the front fork to malfunction.

23Nm(2,3m·kg,17ft·lb)

Perno de fijacion (mensula inferior) ②

20Nm(2,0m·kg,14ft·lb)

PRECAUCTION:

Extent of removal: ① Swingarm removal

Extent of removal Order Part name Q'ty Remarks
Preparation for removalHold the STEERING REMOVALmachine by placing thesuitable stand under the engine.Brake hose holderRear caliperBolt (brake pedal)Drive chainWARNINGSupport the machine securely so there is nodanger of it falling over.Refer to “FRONT BRAKE AND REAR BRAKE” section.Shift the brake pedal backward.
1 Chain support 12 Chain tensioner (lower) 13 Bolt (rear shock absorber-relayarm)4 Bolt (connecting rod) 15 Pivot shaft 16 Swingarm1 Hold the swingarm.

BRAS OSCILLANT

② Connecting rod removal and disassembly

③ Relay arm removal and disassembly

Extent of removal Order Part name Q'ty Remarks
SWINGARM DISASSEMBLY
Relay arm 1
Connecting rod 1
Collar 2
Oil seal 2
Thrust bearing 2
Bush 2
Oil seal 8
Bearing 8Refer to "REMOVAL POINTS".

DEMONTAGE DU BRAS OSCILLANT

Install the bearing by pressing its outer race.

EC574010

INSPECTION

Wash the bearings, bushes, collars, and covers in a solvent.

EC574111

Swingarm

  1. Inspect:

-Bearing ①
Bush ②

Free play exists/unsmooth revolution/ rust Replace bearing and bush as a set.

  1. Inspect:

. Oil seal ③

Damage Replace.

YAMAHA WR400F (1999) - Swingarm - 1

YAMAHA WR400F (1999) - Swingarm - 2

EC574210

Relay arm

  1. Inspect:

-Bearing ①
.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:

-Bearing ①
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. Déposcer:

Roulement ①

N.B.:

ASSEMBLY AND INSTALLATION

EC575201

Bearing and oil seal

  1. Install:

-Bearing ①
. 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 WR400F (1999) - NOTE: - 1

Installed depth of bearings: Outer a: Zero mm (Zero in) Inner b: 8.5 mm (0.33 in)

2.Install:

-Bearing ①
. 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 WR400F (1999) - NOTE: - 1

Installed depth of bearings @: 5 mm (0.20 in)

  1. Install:

.Bearing ①
. 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 WR400F (1999) - NOTE: - 1

Installed depth of bearings @: 5 mm (0.20 in)

REMONTAGE ET MONTAGE

.Bush ①
- Thrust bearing ②
. Oil seal ③
Collar ④

To swingarm ⑤.

NOTE:

Apply the molybdenum disulfide grease on the bushes, thrust bearings and oil seal lips.

  1. Install:

Collar ①

To relay arm ②.

NOTE:

Apply the molybdenum disulfide grease on the collars, bearings and oil seal lips.

  1. Install:

Collar ①

To connecting rod ②.

NOTE:

Apply the molybdenum disulfide grease on the collar, bearings and oil seal lips.

  1. Install:

  2. Connecting rod ①
    Bolt (connecting rod) ②
    Plain washer ③
    .Nut (connecting rod) ④

80Nm (8.0m· kg,58ft· lb)

To relay arm ⑤.

NOTE:

Apply the molybdenum disulfide grease on the bolt.

CAUTION:

Install the nut on the left side of the chassis. If you make a mistake in its installation position, the nut contacts the swingarm when stroking the rear shock absorber.

Bras oscillant

  1. Monter:

Relay arm ①
Bolt (relay arm) ②
Plain washer ③
Nut (relay arm) ④ To swingarm.

NOTE:

  • Apply the molybdenum disulfide grease on the bolt.
  • Do not tighten the nut yet.

  • Install:

-Swingarm ①
.Pivot shaft ②

85Nm(8.5m·kg,61ft·lb)

NOTE:

  • Apply the molybdenum disulfide grease on the pivot shaft.
  • Insert the pivot shaft from right side.

  • Check:

Swingarm side play ⑧
Free play exists Replace thrust bearing.
- Swingarm up and down movement (6) Unsmooth movement/binding/rough spots Grease or replace bearings, bushes and collars.

  1. Install:

  2. Bolt (connecting rod) ①
    Plain washer ②
    .Nut (connecting rod) ③

NOTE:

  • Apply the molybdenum disulfide grease on the bolt.
  • Do not tighten the nut yet.

  • Install:

Plain washer ①
Bolt (rear shock absorber-relay arm) ②

53 Nm (5.3 m·kg, 38 ft·lb)

NOTE:

  • Apply the molybdenum disulfide grease on the bolt.
  • Insert the bolt from right side.

5. Monter:

  • Bras de relais ①
    Boulon (bras de relais) ②
    Rondelle ordinaire ③
  • Ecrou (bras de relais) ④ Sur le bras oscillant

N.B.:

NOTE: Install the cap with its mark @ facing forward.

13.Install:

  • Bolt [chain tensioner (lower)] ①
    Plain washer ②
    -Collar ③
  • Chain tensioner ④
  • Nut [chain tensioner (lower)] ⑤

19Nm (1.9 m·kg, 13 ft·lb)

14.Install:

Chain support ①
Support cover ②
- Bolt{chain support [ = 50mm (1.97 in)]} ③
.Nut (chain support) ④

7Nm (0.7m· kg,5.1ft· lb)

  • Bolt{support cover [ = 10mm (0.39 in)]} ⑤

7Nm (0.7m· kg,5.1ft· lb)

  1. Serrer:

  2. Ecrou (bielle) ①

80Nm(8,0m·kg,58ft·lb)

  1. Festziehen:

① Rear shock absorber removal

② Rear shock absorber disassembly

Extent of removal Order Part Name Q'ty Remarks
Preparation for removalREAR SHOCK ABSORBER REMOVAL Hold the machine by placing the suitable stand under the engine. Seat, fitting band and side covers Silencer Refer to "EXHAUST PIPE Drain the coolant. Refer to "COOLANT Coolant reservoir Refer to "RADIATOR" section in the CHAPTER 4.Refer to "SEAT, FUEL TANK AND SIDE COVERS" section in the CHAPTER 4. SILENCER" section in the CHAPTER 4. LACENENTR" section in the CHAPTER 3. CHAPTER 4.
1 Tail light connector 2
2 Band 2
3 Bolt (brake reservoir tank) 1
4 Clamp (air cleaner joint)1 Only lo
5 Rear frame 1
6 Bolt (rear shock absorber-relay arm)1Holding the swingarm.
7 Bolt (rear shock absorber-frame)
8 Rear shock absorber1

AMORTISSEUR ARRIERE

This 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 shock absorber into an open flame or other high heat. The 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 shock absorber, follow the instructions on disposal.

YAMAHA WR400F (1999) - AMORTISSEUR ARRIERE - 1

EC587000

NOTES ON DISPOSAL (YAMAHA DEALERS ONLY)

Before disposing the 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 shock absorber, take the unit to your Yamaha dealer for this disposal procedure.

REMARQUES CONCERNANT LA MANIPULATION

AVERTISSEMENT

  1. Remove:

  2. Stopper ring ①

NOTE: Press in the bearing while pressing its outer race and remove the stopper ring.

  1. Remove:

-Bearing ①

NOTE: Remove the bearing by pressing its outer race.

EC584000

INSPECTION

EC584110

Rear shock absorber

  1. Inspect:

  2. Damper rod ①

Bends/damage Replace absorber assembly.

Shock absorber ②

Oil leaks Replace absorber assembly.

Gas leaks Replace absorber assembly.

Spring ③

Damage Replace spring.

Fatigue Replace spring.

Move spring up and down.

Spring guide ④

Wear/damage Replace spring guide.

-Bearing ⑤

Free play exists/unsmooth revolution/ rust Replace.

EC585000

ASSEMBLY AND INSTALLATION

EC585300

Bearing

  1. Install:

-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.

POINTS DE DEPOSE

Roulement

  1. Déposser:

Bague d'arrêt ①

N.B.:

After installing the stopper ring, push back the bearing until it contacts the stopper ring.

EC585111

Spring (rear shock absorber)

1.Install:

Spring ①
Spring guide (upper) ②
Spring guide (lower) ③

  1. Tighten:

  2. Adjuster ①

  3. Adjust:

Spring length (installed) @

Spring length (installed) @:
Standard lengthExtent of adjustment
245 mm (9.65 in) *244 mm (9.61 in)242 ~ 260 mm (9.53 ~ 10.24 in)
  • For EUROPE

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.

  1. Tighten:

.Locknut ①

AMORTISSEUR ARRIERE FEDERBEIN AMORTIGUADOR TRASERO

YAMAHA WR400F (1999) - AMORTISSEUR ARRIERE FEDERBEIN AMORTIGUADOR TRASERO - 1

  1. Monter:

Bague d'arrêt ①

New

  1. Montieren:

Sicherungsring ①

New

  1. Instalar:

Aro de tope ①

New

N.B.:

  • Apply the molybdenum disulfide grease on the bearings.
  • Apply the lithium soap base grease on the dust seals, O-rings and collars.

  • Install:

Rear shock absorber

  1. Install:

Bolt (rear shock absorber-frame) ①
Nut (rear shock absorber-frame) ②

56Nm(5.6m·kg,40ft·lb)

NOTE:

Apply the molybdenum disulfide grease on the bolt.

  1. Install:

Plain washer ①
Bolt (rear shock absorber-relay arm) ②

53Nm(5.3m·kg,38ft·lb)

NOTE:

  • Apply the molybdenum disulfide grease on the bolt.
  • Insert the bolt from right side.

  • Install:

Rear frame ①
Bolt (rear frame) ②

26Nm(2.6m·kg,19ft·lb)

Bolt (reservoir tank) ③
10Nm(1.0m·kg,7.2ft·lb)

  1. Tighten:

Screw (air cleaner joint) ①

Amortisseur arrêté

  1. Monter:

Joint antipoussiere ①
Joint torque ②
Collerette ③

New

N.B.:

26Nm(2,6m·kg,19ft·lb)

A map-controlled, CDI ignition system is used in the WR400F.

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 WR400F (1999) - N.B.: - 1

Function of Component

Component Function
TPS(throttle position sensor)Detects throttle valve opening and inputs it into the computer in the CDI unit as a throttle opening signal.
Pickup coil Detects signal rotor revolutions and inputs them into the computer in the CDI unit as engine revolution signals.
CDI unit The signals of the TPS 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 WR400F (1999) - Principal of 3-Dimensional Control - 1
3-D Image Map of Ignition Timing (different from actual characteristics)

BLOC CDI CONTROLE PAR MICROPROCESSEUR

Control tridimensional principal

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 WR400F (1999) - Control tridimensional principal - 1

*: 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 WR400F (1999) - NOTE: - 1

Dynamic spark tester: YM-34487

Ignition checker: 90890-06754

YAMAHA WR400F (1999) - NOTE: - 2

Pocket tester: YU-03112/90890-03112

SYSTEME D'ALLUMAGE

ETAPES DU CONTROL

  1. Disconnect the spark plug cap from spark plug.
  2. Connect the dynamic spark tester ① (ignition checker ②) as shown.
    Spark plug cap ③
    Spark plug ④

For USA and CDN

Except for USA and CDN

  1. Kick the kick starter.
  2. Check the ignition spark gap.
  3. Start engine, and increase spark gap until misfire occurs. (for USA and CDN only)

YAMAHA WR400F (1999) - ETAPES DU CONTROL - 1

Minimum spark gap: 6.0 mm (0.24 in)

EC624000

COUPLERS AND LEADS CONNECTION INSPECTION

  1. Check:

  2. Couplers and leads connection Rust/dust/looseness/short-circuit Repair or replace.

YAMAHA WR400F (1999) - COUPLERS AND LEADS CONNECTION INSPECTION - 1

EC625001

"ENGINE STOP" BUTTON INSPECTION

  1. Inspect:

. "ENGINE STOP" button conduct

Tester (+) lead → Black/White lead ① Tester (-) lead → Black lead ②
B/W ①B ②Tester selec- tor position
PUSH INΩ·1
FREE

No continuity while being pushed Replace. Continuity while being freed Replace.

TEST DE L'INTERVALLE D'ETINCELEMENT D'ALLUMAGE

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 WR400F (1999) - IGNITION COIL INSPECTION - 1

  1. 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.

EC627011

CDIMAGNETOINSPECTION

  1. Inspect:

Pick-up coil resistance

Out of specification Replace.

YAMAHA WR400F (1999) - CDIMAGNETOINSPECTION - 1

Tester (+) lead → Red lead ① Tester (-) lead → White lead ②
Pick-up coil resistanceTester selector position
248 ~ 372 Ω at 20 °C (68 °F)Ω·100

CONTROLE DE LA BOBINE D'ALLUMAGE

Source coil 1 resistance

Out of specification Replace.

Tester (+) lead → Brown lead ①
Tester (−) lead → Green lead ②
Source coil 1 resistanceTester selector position
640 ~ 960 Ω at 20 °C (68 °F)Ω · 100
  1. Inspect:

Source coil 2 resistance

Out of specification Replace.

Tester (+) lead → Pink lead ① Tester (-) lead → Green lead ②
Source coil 2 resistanceTester selector position
464 ~ 696 Ω at 20 °C (68 °F)Ω · 10

YAMAHA WR400F (1999) - CONTROLE DE LA BOBINE D'ALLUMAGE - 1

NEUTRAL SWITCH INSPECTION

  1. Inspect:

Neutral switch conduct

Tester (+) lead → Sky blue lead ① Tester (-) lead → Ground
Sb ①GroundTester selec- tor position
NEU- TRAL○-○Ω·1
INGEAR

No continuity while in neutral Replace.

Continuity 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. Verifier:

If the TPS will not operate, use the following inspection steps.

YAMAHA WR400F (1999) - Verifier: - 1

*marked: Refer to "IGNITION SYSTEM" section.

NOTE:

  • Remove the following parts before inspection.

1) Seat
2) Fuel tank

  • Use the following special tools in this inspection.

YAMAHA WR400F (1999) - NOTE: - 1

Pocket tester: YU-03112/90890-03112

YAMAHA WR400F (1999) - NOTE: - 2

Inductive tachometer: YU-8036-1
Engine tachometer: 90890-03113

SYSTEME TPS (CAPTEUR DU PAPILLON D'ACCELERATION)

ETAPES DU CONTROLE

  1. Check:

  2. Couplers and leads connection Rust/dust/looseness/short-circuit Repair or replace.

YAMAHA WR400F (1999) - ETAPES DU CONTROLE - 1

TPS COIL INSPECTION

  1. Inspect:

TPS coil resistance

Out of specification Replace.

Tester (+) lead Blue lead ①

Tester (-) lead Black lead ②

TPS coil resistanceTester selector position
4 ~ 6 kΩ at 20 °C (68 °F)kΩ·1
  1. Loosen:

  2. Throttle stop screw

NOTE:

Turn out the throttle stop screw until the throttle shaft is in the full close position.

YAMAHA WR400F (1999) - NOTE: - 1

  1. Inspect:

TPS 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
TPS coil variable resistanceTester selec- tor position
Full closedFull openedkΩ·1
0 ~ 2 kΩ at 20 °C (68 °F)4 ~ 6 kΩ at 20 °C (68 °F)

CONTROLE DES CONNXIONS DES COUPLEURS ET DES FILS

TPS REPLACEMENT AND ADJUSTMENT

  1. Remove:

TPS coupler
Screw (TPS) ①
Plain washer ②
.TPS ③

  1. Replace:

.TPS

  1. Install:

.TPS ①
Plain washer ②
Screw (TPS) ③
TPS coupler

NOTE:

Align the slot 已 in the TPS with the projection 已 on the carburetor.
- Temporarily tighten the screws (TPS).

  1. Adjust:

Idle speed

Refer to "IDLE SPEED ADJUSTMENT" section in the CHAPTER 3.

  1. Calculate:
  2. TPS coil resistance at idle speed.

TPS coil resistance at idle speed: TPS coil resistance (0.13 0.15)

If the TPS coil resistance is 5k then the TPS coil resistance at idle speed is:

5k · (0.13 0.15) = 650 750

Refer to "TPS COIL INSPECTION" section about the TPS coil resistance.

REEMPLACEMENT ET REGLAGE DU TPS

  1. Adjust:

  2. TPS coil resistance at idle speed

Adjustment steps:

Adjust the angle of the TPS ① to obtain the resistance calculated (example: 650 750Ω)

Tester (+) lead Yellow lead ②

Tester (-) lead Black lead ③

  1. Tighten:

Screw (TPS) ①

  1. Install:

TPS coupler

EC694000

TPS INPUT VOLTAGE INSPECTION

  1. Disconnect the TPS coupler.
  2. Start the engine.
  3. Inspect:

TPS input voltage

Out of specification Replace the CDI unit.

Tester (+) lead → Blue lead ① Tester (-) lead → Black lead ②
TPS input voltageTester selector position
4 ~ 6 V DCV-20

Refer to the following flow chart when inspecting the ignition system for possible problems.

YAMAHA WR400F (1999) - TPS INPUT VOLTAGE INSPECTION - 1

NOTE:

  • Replace the bulb and/or bulb socket.

1) Seat
2) Fuel tank

  • Use the following special tool.

YAMAHA WR400F (1999) - NOTE: - 1

Pocket tester: YU-03112/90890-03112

SYSTEME D'ECLAIRAGE

PROCEDURES DE VERIFICATION

  1. Inspect:

  2. Lights switch conduct

Tester (+) lead → Yellow lead ① Tester (-) lead → Blue lead ②
Y ①L ②Tester selec- tor position
Ω·1
OFF

No continuity while being Replace.

Continuity while being OFF Replace.

YAMAHA WR400F (1999) - PROCEDURES DE VERIFICATION - 1

CDIMAGNETOINSPECTION

  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

VERIFICATION INTERRUPEUR LUMIERES

  1. Verifier:
  • 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 WR400F (1999) - 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.

CAUTION:

  • 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.

YAMAHA WR400F (1999) - CAUTION: - 1

MISES AU POINT MOTEUR

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)Mixture Setting
High HighLow (high)Richer Leaer
Low LowHigh (low)Leaer Richer

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.

YAMAHA WR400F (1999) - Atmospheric conditions and carburetor settings - 1
A Closed
Fully open

Effects of the setting parts on the throttle valve opening
YAMAHA WR400F (1999) - Atmospheric conditions and carburetor settings - 2
① Pilot screw/Pilot jet
② Piston valve cutaway
③ Jet needle
④ Main jet

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.

① Jet needle
② Main air jet
③ Pilot air jet
④ Needle jet
⑤ Main jet
⑥ Pilot jet
⑦ Pilot screw

Pilot system

The FLATCR carburetor is manufactured with a pilot screw. The adjusting range of the pilot screw is limited by the throttle opening during idling.

Circuit principal

The richness of the air-fuel mixture at full throttle can be set by changing the main jet ①.

Standard main jet #165

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 WR400F (1999) - Effects of changing the main jet (reference) - 1

A Idle
Fully open

YAMAHA WR400F (1999) - Effects of changing the main jet (reference) - 2

Pilot screw adjustment

The richness of the air-fuel mixture with the throttle fully closed to 1/8 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 position1-5/8 turns out * 1-1/2 turns out (for reference only)
  • Except for USA

NOTE:

The pilot screw is set at the factory, there is no need to adjust it.

If the idling speed fluctuates, turn the pilot screw only 1/2 of a turn in either direction.

Effects of adjusting the pilot screw (reference)

YAMAHA WR400F (1999) - Effects of adjusting the pilot screw (reference) - 1

A Idle
Fully open
① 2-1/8 turns out
② 1-1/8 turns out
③ 1-5/8 turns out

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.

If the engine breathes hard when you start opening the throttle, the air-fuel mixture is too rich and should be made leaner.

Standard pilot jet #42

Effects of adjusting the pilot jet (reference)

YAMAHA WR400F (1999) - Effects of adjusting the pilot jet (reference) - 1

A Idle
Fully open

Jet needle groove position adjustment

Adjusting the jet needle ① position affects the acceleration when the throttle is 1/4 to 1/2 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.

  1. 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
  • Except for USA

Effects of changing the jet needle groove position (reference)

YAMAHA WR400F (1999) - Effects of changing the jet needle groove position (reference) - 1

A Idle
Fully open
① No.4groove
② No.2 groove
③ No.3 groove

Jet needle adjustment

The jet needle is adjusted by changing it.

Standard jet needleOBDRS *OBRQ

YAMAHA WR400F (1999) - Jet needle adjustment - 1

  • Except for USA

The tapered sections of all jet needles have the same starting positions, but the needles are available with different taper angles and straight-partion diameters.

YAMAHA WR400F (1999) - Jet needle adjustment - 2

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 WR400F (1999) - Effects of changing the jet needle (reference) - 1

A Idle
Fully open

(Taper)

A smaller taper affects the richness of the air-fuel mixture when the throttle is fully open. To change the air-fuel mixture only at 1/2 throttle, also adjust the main jet.

YAMAHA WR400F (1999) - (Taper) - 1

A Idle
Fully open

YAMAHA WR400F (1999) - (Taper) - 2
A Lean (larger diameter)
Rich (smaller diameter)
① 1/8 throttle
② 1/4 throttle
③ 1/2 throttle
④ 1/1 throttle
(a) Main nozzle

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 taper starting position and the clip position with the throttle 1/4 to fully open.

Therefore, the fuel flow is balanced at each stage of throttle opening by the combination of the jet needle straight portion diameter, taper starting position and clip position.

Carburetor setting parts

Part name SizePart number
Main jet Rich (STD) Lean#178 #175 #172 #170 #168 #165 #162 #160 #158 #1554MX-14943-93 4MX-14943-42 4MX-14943-92 4MX-14943-41 4MX-14943-91 4MX-14943-40 4MX-14943-90 4MX-14943-39 4MX-14943-89 4MX-14943-38
Pilot jet Rich (STD) Lean#48 #45 #42 #40 #384MX-14948-06 4MX-14948-05 4MX-14948-04 4MX-14948-03 4MX-14948-02
Jet needle Rich (STD) Lean#DRP #DRQ #DRR #DRS #DRT #DRU #DRV5GS-14916-RP 5GS-14916-R1 5GS-14916-RR 5GS-14916-RS 5GS-14916-RT 5GS-14916-RU 5GS-14916-RV
Jet needle Rich *(STD) Lean#DRM #DRN #DRP #DRQ #DRR #DRS #DRT5GS-14916-RM 5GS-14916-RN 5GS-14916-RP 5GS-14916-R1 5GS-14916-RR 5GS-14916-RS 5GS-14916-RT
  • Except for USA

Examples of carburetor setting depending on symptom

Symptom Setting Checking
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 cockAccelerator pump
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 cleanerFuel overflow from carburetor
Lean mixture Lower jet needleclip position.(1 groove down)
Rich mixture Raise jet needleclip position.(1 groove up)Leaning↑(Standard)↓Richer
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)The clip position is the jet needle groove on which the clip is installed.The positions are numbered from the top.Accelerator pump (except for rich mixture symptom).
Closed to 1/4 throttleHard breathingSpeed downUse jet needle with a smaller diameter.Slow-speed-circuit passageClogged → Clean.Overflow from carburetorAccelerator pump
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 that the accelerator pump operates smoothly.Check air cleaner for fouling.
  • 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

$$ \frac {\text {r e d u c t i o n}}{\text {r a t i o}} = \frac {\text {N u m b e r o f d r i v e s p r o c k e t t e e t h}}{\text {N u m b e r o f d r i v e s p r o c k e t t e e t h}} $$

Standard secondary reduction ratio

50/14 (3.571)

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.

PARTIC CYCLE

EC72N000
Drive and driven sprockets setting parts

Part name SizePart number
Drive sprocket ① (STD)14T 9383E-14215
Driven sprocket ② (STD)48T5GS-25448-50
50T5GS-25450-50
52T5GS-25452-50

EC721002

Tire pressure

Tire pressure should be adjust to suit the road surface condition of the circuit.

YAMAHA WR400F (1999) - Tire pressure - 1

Standard tire pressure: 100 kPa (1.0 kg/cm², 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 WR400F (1999) - Standard tire pressure: 100 kPa (1.0 kg/cm², 15 psi) - 1

Extent of adjustment: 60 80kPa (0.6 0.8kg / cm^2,9.0 12 psi)

  • Under a stony or hard road condition, the tire pressure should be higher to prevent a flat tire.

YAMAHA WR400F (1999) - Extent of adjustment: 60 80kPa (0.6 0.8kg / cm^2,9.0 12 psi) - 1

Extent of adjustment: 100 ~ 120 kPa (1.0 ~ 1.2 kg/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
  2. Change the fork oil level.

  3. Setting of spring preload

  4. Change the spring.
    Install the adjustment washer.

  5. Setting of damping force

  6. Change the compression damping.

  7. 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.

YAMAHA WR400F (1999) - Change in level and characteristics of fork oil - 1

CAUTION:

Adjust the oil level in 5mm (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.

YAMAHA WR400F (1999) - CAUTION: - 1

Standard oil level:

135 mm (5.31 in)

*125 mm (4.92 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
    Load
    Stroke
    ① Max. oil level
    ② Standard oil level
    ③ Min. oil level

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 WR400F (1999) - 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.

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.

YAMAHA WR400F (1999) - Setting of spring after replacement - 1

A Coverage of spring by weight
Rider weight
① Soft
② Standard
③ Stiff

2. Ressort dur

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
0.4104SS-23141-40I
*STD 0.420 4SR-23141-L0-
0.4304SS-23141-60III
0.4404SS-23141-70III
0.4505BE-23141-L0-
STD 0.460 5GR-23141-L0-
STIFF 0.470 5GR-23141-00 II-II
  • For EUROPE

[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 WR400F (1999) - Rear suspension setting - 1

YAMAHA WR400F (1999) - Rear suspension setting - 2

YAMAHA WR400F (1999) - Rear suspension setting - 3

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 ⑧ 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 ⑤ 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 ⑧.

YAMAHA WR400F (1999) - Choosing set length - 1

  • 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.

EC72G001

Setting of spring after replacement

After replacement, be sure to adjust the spring to the set length and [sanken length 90 100~mm (3.5 3.9in)] set it.

  1. Use of soft spring
  2. 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.
  3. Use of stiff spring
  4. 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.
  5. 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.:

When using a rear cushion other than currently installed, use the one whose overall length 已 does not exceed the standard as it may result in faulty performance. Never use one whose overall length is greater than standard.

YAMAHA WR400F (1999) - N.B.: - 1

Length @ of standard shock: 485.5 mm (19.11 in)

A Coverage of spring by weight
Rider weight
① Soft
② Standard
③ Stiff

ATTENTION:

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
*STD4.8 5DH-22212-20 Red/1260
STD5.0 5DH-22212-30 Black/1260
STIFF5.25DH-22212-40Blue/1260
5.45DH-22212-50Yellow/1265
5.65DH-22212-60Pink/1265
  • For EUROPE

[Unequal pitch spring]

TYPESPRING RATE (approx.)SPRING PART NUMBERI.D. COLOR/ POINTSPRING FREE LENGTH
SOFT4.65ET-22212-20Green/2275
4.85ET-22212-00Red/2275
5.05ET-22212-10Black/2275
5.25ET-22212-30Blue/2275
5.45ET-22212-40Yellow/2275
STIFF5.65ET-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 (包) is marked at the end of the spring.

YAMAHA WR400F (1999) - NOTE: - 1

  • Extent of adjustment (spring length) ⑥
SPRING FREE LENGTHEXTENT OF ADJUSTMENT
260 mm (10.24 in)242 ~ 260 mm (9.53 ~ 10.24 in)
265 mm (10.43 in)247 ~ 265 mm (9.72 ~ 10.43 in)
275 mm (10.83 in)257 ~ 275 mm (10.12 ~ 10.83 in)
280 mm (11.02 in)262 ~ 280 mm (10.31 ~ 11.02 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).
SymptomSectionCheck Adjust
JumpLarge gapMedium gapSmall gap
Stiff over entire rangeCompression damping Oil 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 tube Inner tube Under bracket tightening torqueCheck for any bends, dents, and other noticeable scars, etc. If any, replace affected parts. Retighten to specified torque.
Poor initial movementRebound damping Oil sealTurn adjuster counterclockwise (about 2 clicks) to decrease damping. Apply grease in oil seal wall.
Soft over entire range, bottoming outCompression damping Oil 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 damping Rebound damping Balance with rear end Oil 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, tend- ing to upper front pos- tureCompression damping Balance with rear end Spring Oil 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.
SymptomSectionCheck Adjust
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 clicks) 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 95 ~ 100 mm (3.7 ~ 3.9 in) when one passenger is astride seat.Replace with soft spring.
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Product information

Brand : YAMAHA

Model : WR400F (1999)

Category : Motorcycle