YAMAHA YZ450F-2007 - Off-road motorcycle

YZ450F-2007 - Off-road motorcycle YAMAHA - Free user manual and instructions

Find the device manual for free YZ450F-2007 YAMAHA in PDF.

📄 650 pages English EN Download 💬 AI Question
Notice YAMAHA YZ450F-2007 - page 47
View the manual : Français FR Deutsch DE English EN
Pick your language and provide your email: we'll send you a specifically translated version.

User questions about YZ450F-2007 YAMAHA

0 question about this device. Answer the ones you know or ask your own.

Ask a new question about this device

The email remains private: it is only used to notify you if someone responds to your question.

No questions yet. Be the first to ask one.

Download the instructions for your Off-road motorcycle in PDF format for free! Find your manual YZ450F-2007 - YAMAHA and take your electronic device back in hand. On this page are published all the documents necessary for the use of your device. YZ450F-2007 by YAMAHA.

USER MANUAL YZ450F-2007 YAMAHA

OWNER'S SERVICE MANUAL

MANUEL D'ATELIER DU

PROPRIETAIRE

FAHRER- UND

WARTUNGSHANDBUCH

YZ450F(W)

EC010010

YZ450F(W)

OWNER'S SERVICE MANUAL

©2006 by Yamaha Motor Co., Ltd.

1st Edition, July 2006

All rights reserved. Any reprinting or

unauthorized use without the written

permission of Yamaha Motor Co., Ltd.

is expressly prohibited.

Printed in Japan

YZ450F(W)

MANUEL D'ATELIER

DU PROPRIETAIRE

©2006 Yamaha Motor Co., Ltd.

Congratulations on your purchase of a Yamaha YZ 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:

Yamaha continually seeks advancements in product design and quality. Therefore, while this manual contains the most current product information available at the time of printing, there may be minor discrepancies between your machine and this manual. If you have any questions concerning this manual, please consult your Yamaha dealer.

YAMAHA YZ450F-2007 - NOTE: - 1

WARNING

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

INTRODUCTION

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

SAFETY INFORMATION

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

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

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

Do not carry passengers on this machine.

  1. ALWAYS WEAR PROTECTIVE APPAREL.

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

  1. ALWAYS MAINTAIN YOUR MACHINE IN PROPER WORKING ORDER.

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

  1. GASOLINE IS HIGHLY FLAMMABLE.

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

NOTICE IMPORTANTE

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

  1. ONLY OPERATE THE MACHINE IN AN AREA WITH ADEQUATE 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 PEUT CAUSER DES BLESSURES.

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

NOTE:

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

EC060000

NOTICE

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

EC070001

F.I.M. MACHINE WEIGHTS:

Weights of machines without fuel

The minimum weights for motocross machines are:

for the class 125 cc minimum

88 kg (194 lb)

for the class 250 cc minimum

98 kg (216 lb)

for the class 500 cc minimum

102 kg (225 lb)

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

AU NOUVEAU PROPRIETAIRE

HOW TO USE THIS MANUAL

EC081000 PARTICULARLY IMPORTANT INFORMATION

YAMAHA YZ450F-2007 - EC081000 PARTICULARLY IMPORTANT INFORMATION - 1

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

YAMAHA YZ450F-2007 - EC081000 PARTICULARLY IMPORTANT INFORMATION - 2

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 YZ450F-2007 - 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.

COMMENT UTILISER CE MANUEL

INFORMATIONS PARTICULIEREMENT IMPORTANTES

YAMAHA YZ450F-2007 - INFORMATIONS PARTICULIEREMENT IMPORTANTES - 1

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

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

  • Bearings

Pitting/damage Replace.

EC084002

HOW TO READ DESCRIPTIONS

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

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

YAMAHA YZ450F-2007 - HOW TO READ DESCRIPTIONS - 1
4-48

YAMAHA YZ450F-2007 - HOW TO READ DESCRIPTIONS - 2
4-50

FORMAT DU MANUEL

ILLUSTRATED SYMBOLS (Refer to the illustration)

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

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

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

⑧ With engine mounted
⑨ Special tool
10 Filling fluid
① Lubricant
② Tightening
③ Specified value, Service limit
④ Resistance () , Voltage (V), Electric current (A)

Illustrated symbols ⑤ to ⑧ in the exploded diagrams indicate grade of lubricant and location of lubrication point.

⑤ Apply engine oil
16 Apply molybdenum disulfide oil
⑦ Apply lightweight lithium-soap base grease
18 Apply molybdenum disulfide grease

Illustrated symbols ⑲ to ② in the exploded diagrams indicate where to apply a locking agent and where to install new parts.

Apply locking agent (LOCTITE®)
Use new one

SYMBOLS GRAPHIQUES (Voir l'illustration)

CHECKING OF CONNECTION 1-6

SPECIAL TOOLS 1-7

CONTROL FUNCTIONS 1-10

FUEL 1-13

STARTING AND BREAK-IN 1-14

TORQUE-CHECK POINTS 1-18

CLEANING AND STORAGE 1-19

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

DIAGRAMME D'ACHEMINEMENT

DES CABLES 2-21

CHAPITRE 3 CONTROLES ET REGLAGES PERIODIQUES

PROGRAMME D'ENTRETIEN 3-1

CONTROLE ET ENTRETIEN

AVANT UTILISATION 3-4

MOTEUR 3-5

CHASSIS 3-24

PARTIE ELECTRIQUE 3-46

VALVES AND VALVE SPRINGS 4-34

CYLINDER AND PISTON 4-43

CLUTCH 4-49

OIL FILTER, WATER PUMP AND

CRANKCASE COVER (RIGHT) 4-56

BALANCER 4-63

OIL PUMP 4-66

KICK AXLE AND SHIFT SHAFT 4-70

CDIMAGNETO 4-78

ENGINE REMOVAL 4-81

CRANKCASE AND CRANKSHAFT 4-86

TRANSMISSION, SHIFT CAM AND

SHIFT FORK 4-95

CHAPTER 5 CHASSIS

FRONT WHEEL AND REAR WHEEL 5-1

CHAPITRE 7 MISE AU POINT

MOTEUR 7-1

CHASSIS 7-11

① Clutch lever
② Hot starter lever
③ Front brake lever
④ Throttle grip
⑤ Radiator cap
⑥ Fuel tank cap
⑦“ENGINE STOP” button
⑧ Kick starter
(9) Fuel tank
⑩ Radiator
Coolant drain bolt
⑫ Rear brake pedal
③ Valve joint
④ Fuel cock
15 Cold starter knob
16 Drive chain
⑦ Air cleaner
Shift pedal
Oil dipstick
Front fork

NOTE:

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

YAMAHA YZ450F-2007 - NOTE: - 1

YAMAHA YZ450F-2007 - NOTE: - 2

YAMAHA YZ450F-2007 - NOTE: - 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 YZ450F-2007 - VEHICLE IDENTIFICATION NUMBER - 1

YAMAHA YZ450F-2007 - VEHICLE IDENTIFICATION NUMBER - 2

YAMAHA YZ450F-2007 - 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 MOTO

EC131010 PREPARATION FOR REMOVAL AND DISASSEMBLY

  1. Remove all dirt, mud, dust, and foreign material before removal and disassembly. When washing the machine with high pressured water, cover the parts as follows.

  2. Silencer exhaust port

  3. Side cover air intake port
    Water pump housing hole at the bottom
  4. Drain hole on the cylinder head (right side)

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

  6. 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.

  7. 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.
  8. Keep away from fire.

INFORMATIONS IMPORTANTES PREPARATION A LA DEPOSE ET AU DEMONTAGE

ALL REPLACEMENT PARTS

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

EC133000

GASKETS, OIL SEALS AND O-RINGS

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

YAMAHA YZ450F-2007 - GASKETS, OIL SEALS AND O-RINGS - 1

YAMAHA YZ450F-2007 - GASKETS, OIL SEALS AND O-RINGS - 2

YAMAHA YZ450F-2007 - GASKETS, OIL SEALS AND O-RINGS - 3

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 light-weight lithium base grease to the seal lip(s). Oil the bearings liberally when installing.

CAUTION:

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

PIECES DE RECHANGE

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

④ Shaft

CIRCLIPS

CHECKING OF CONNECTION

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

  1. Disconnect:

  2. Connector

  3. Dry each terminal with an air blower.

  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 wire harness.
  • For a field remedy, use a contact revitalizer available on the market.
  • Use the tester on the connector as shown.

VERIFICATION DES CONNXIONS

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

NOTE:

  • For U.S.A. and Canada, use part number starting with "YM-," "YU-" or "ACC-".
  • For others, use part number starting with "90890".
Part numberTool name/How to useIllustration
YU-3097, 90890-01252 YU-1256Dial gauge and stand Stand These tools are used to check each part for runout or bend.YU-3097 YU-125690890-01252
YU-90050, 90890-01274 YU-90050, 90890-01275 YU-91044, 90890-04081 YU-90063, 90890-01278Crankshaft installing tool Crankshaft installing pot Crankshaft installing bolt Spacer (crankshaft installer) Adapter (M12) These tools are used to install the crankshaft.YU-90050 YU-90063 YU-9104490890-01274 90890-01275 90890-01278 90890-04081
YU-1304, 90890-01304Piston pin puller This tool is used to remove the piston pin.YU-130490890-01304
YU-24460-01, 90890-01325 YU-33984, 90890-01352Radiator cap tester Adapter These tools are used for checking the cooling sys- tem.YU-24460-01 YU-3398490890-01325 90890-01352
YM-04151, 90890-04151Rotor puller This tool is used to remove the flywheel magneto.YM-0415190890-04151
YU-33975, 90890-01403Ring nut wrench This tool is used when tighten the steering ring nut to specification.YU-3397590890-01403
YM-01500, 90890-01500Cap bolt wrench This tool is used to loosen or tighten the base valve.YM-0150090890-01500
YM-01501, 90890-01501Cap bolt ring wrenchYM-0150190890-01501
This tool is used to loosen or tighten the damper assembly.
YM-A0948, 90890-01502Fork seal driverYM-A094890890-01502
This tool is used when install the fork oil seal.
YU-3112-C, 90890-03112Pocket testerYU-3112-C90890-03112
Use this tool to inspect the coil resistance, output voltage and amperage.
YM-33277-A, 90890-03141Timing lightYM-33277-A90890-03141
This tool is necessary for checking ignition timing.
YM-4019, 90890-04019Valve spring compressorYM-401990890-04019
This tool is needed to remove and install the valve assemblies.
YM-91042, 90890-04086Clutch holding toolYM-9104290890-04086
This tool is used to hold the clutch when removing or installing the clutch boss securing nut.
YM-4116, 90890-04116Valve guide removerYM-411690890-04116
YM-4097, 90890-04097Intake 4.5 mm (0.18 in)YM-409790890-04097
Exhaust 5.0 mm (0.20 in)
This tool is needed to remove and install the valve guide.
YM-4117, 90890-04117Valve guide installerYM-411790890-04117
YM-4098, 90890-04098Intake ExhaustYM-409890890-04098
This tool is needed to install the valve guide.
YM-4118, 90890-04118Valve guide reamerYM-411890890-04118
YM-4099, 90890-04099Intake 4.5 mm (0.18 in)YM-409990890-04099
Exhaust 5.0 mm (0.20 in)
This tool is needed to rebore the new valve guide.
YU-A9642, 90890-04152Crankcase separating tool These tool is used to remove the crankshaft from either case.YU-A964290890-04152
YM-34487 90890-06754Dynamic spark tester Ignition checker This instrument is necessary for checking the ignition system components.YM-3448790890-06754
90890-85505YAMAHA Bond No. 1215 (ThreeBond® No.1215) This sealant (Bond) is used for crankcase mating surface, etc.90890-8550590890-85505

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.

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.

FONCTIONS DES COMMANDES

BOUTON "ENGINE STOP"

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

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.

EC158001

FUEL COCK

The fuel cock supplies fuel from the tank to carburetor while filtering the fuel. The fuel cock has the two 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.

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.

HOT STARTER LEVER

The hot starter lever ① is used when starting a warm engine.

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

LEVIER DE FREIN AVANT

This sidestand ① is used to support only the machine when standing or transporting it.

WARNING

  • Never apply additional force to the side-stand.
  • Remove this sidestand before starting out.

EC15E000

VALVE JOINT

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

CAUTION:

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

SPARK PLUG WRENCH

This spark plug wrench ① is used to remove and install the spark plug.

NIPPLE WRENCH

This nipple wrench ① is used to tighten the spoke.

JET NEEDLE PULL-UP TOOL

The jet needle pull-up tool ① is used to pull the jet needle out of the carburetor.

BEQUILLE LATERALE AMOVIBLE

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

YAMAHA YZ450F-2007 - BEQUILLE LATERALE AMOVIBLE - 1

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

CAUTION:

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

NOTE:

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

WARNING

  • For refueling, be sure to stop the engine and use enough care not to spill any fuel. Also be sure to avoid refueling close to a fire.
  • Refuel after the engine, exhaust pipe, etc. have cooled off.

CARBURANT

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 machine 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.
  • Before starting the machine, perform the checks in the pre-operation check list.

YAMAHA YZ450F-2007 - CAUTION: - 1

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 ①.
  5. Kick the kick starter.

WARNING

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

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

NOTE:

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

CAUTION:

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

Do not operate the cold starter knob and throttle. Pull the hot starter lever ① and start the engine by kicking the kick starter forcefully with a firm stroke.

As soon as the engine starts, release the hot starter lever to close the air passage.

Restarting an engine after a fall

Pull the hot starter lever and start the engine. As soon as the engine starts, release the hot starter lever to close the air passage.

The engine fails to start

Pull the hot starter lever all the way out and while holding the lever, kick the kick starter 10 to 20 times to clear the engine.

Then, restart the engine.

Refer to "Restarting an engine after a fall".

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

CAUTION:

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

  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 machine 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, CAMSHAITS 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

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

POINTS DE VERIFICATION DES COUPLES DE SERRAGE

YAMAHA YZ450F-2007 - POINTS DE VERIFICATION DES COUPLES DE SERRAGE - 1

YAMAHA YZ450F-2007 - POINTS DE VERIFICATION DES COUPLES DE SERRAGE - 2

ANZUGSDREHMOMENTE KONTROLLIEREN

YAMAHA YZ450F-2007 - ANZUGSDREHMOMENTE KONTROLLIEREN - 1

CLEANING AND STORAGE

EC1B1000

CLEANING

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

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

CAUTION:

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

  1. After the majority of the dirt has been hosed off, wash all surfaces with warm water and a mild detergent. Use an old toothbrush to clean hard-to-reach places.
  2. Rinse the machine off immediately with clean water, and dry all surfaces with a soft towel or cloth.
  3. Immediately after washing, remove excess water from the chain with a paper towel and lubricate the chain to prevent rust.
  4. Clean the seat with a vinyl upholstery cleaner to keep the cover pliable and glossy.

NETTOYAGE ET REMISAGE

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.

Model name:YZ450FW (USA, CDN, AUS, NZ)YZ450F (EUROPE, ZA)
Model code number:2S27 (USA, CDN)2S28 (EUROPE)2S2A (AUS, NZ, ZA)
Dimensions:USA, CDN,ZA, AUS, NZEUR(Except for F)F
Overall length2,191 mm(86.26 in)2,196 mm(86.48 in)2,197 mm(86.50 in)
Overall width825 mm(32.48 in)
Overall height1,306 mm(51.42 in)1,308 mm(51.50 in)1,309 mm(51.54 in)
Seat height989 mm(38.94 in)1,002 mm(39.45 in)
Wheelbase1,494 mm(58.82 in)
Minimum ground clearance373 mm(14.69 in)376 mm(14.80 in)
Dry weight:Without oil and fuel99.8 kg (220 lb)
Engine:Engine typeLiquid cooled 4-stroke, DOHCSingle cylinder, forward inclined
Cylinder arrangementSingle cylinder, forward inclined
Displacement449 cm3 (15.8 Imp oz, 15.2 US oz)
Bore × stroke95.0 × 63.4 mm (3.74 × 2.50 in)
Compression ratio12.3 : 1
Starting systemKick starter
Lubrication system:Dry sump
Oil type or grade: Engine oil 0 10 30 50 70 90 110 130 °F YAMALUBE 4(10W-30) or SAE 10W-30 YAMALUBE 4(20W-40) or SAE 20W-40 YAMALUBE 4-R(10W-50) or SAE 10W-50 °C -20 -10 0 10 20 30 40 50 °C -20 -10 0 10 20 30 40 50 °C SAE 10W-30 SAE 10W-40 SAE 15W-40 SAE 20W-40 SAE 20W-50(For USA and CDN) Yamalube 4, SAE10W30 or SAE20W40 Yamalube 4-R, SAE10W50 API service SG type or higher JASO standard MA (Except for USA and CDN) SAE10W30, SAE10W40, SAE15W40, SAE20W40 or SAE20W50 API service SG type or higher JASO standard MA
Oil capacity: Engine oil Periodic oil change With oil filter replacement Total amount0.95 L (0.84 Imp qt, 1.00 US qt) 1.0 L (0.88 Imp qt, 1.06 US qt) 1.2 L (1.06 Imp qt, 1.27 US qt)
Coolant capacity (including all routes):0.99 L (0.87 Imp qt, 1.05 US qt)
Air filter:Wet type element
Fuel: TypePremium unleaded gasoline only with a research octane number of 95 or higher. 7.0 L (1.54 Imp gal, 1.85 US gal)
Tank capacity
Carburetor: TypeFCR MX39
ManufacturerKEIHIN
Spark plug: Type/manufacturerCR8E/NGK (resistance type) 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
GapWet, multiple-disc
Clutch type:
Transmission:
Primary reduction systemGear
Primary reduction ratio61/23 (2.652)
Secondary reduction systemChain drive
Secondary reduction ratio49/13 (3.769)
Transmission typeConstant mesh, 5-speed
OperationLeft foot operation
Gear ratio: 1st27/14 (1.929)
2nd23/15 (1.533)
3rd23/18 (1.278)
4th24/22 (1.091)
5th20/21 (0.952)
Chassis:USA, CDN, ZA, AUS, NZEUR (Except for F)F
Frame typeSemi double cradle
Caster angle26.8°26.9°
Trail114.1 mm (4.49 in)115.3 mm (4.54 in)116.3 mm (4.58 in)
Tire:
TypeWith tube
Size (front)80/100-21 51M (For USA, CDN, ZA, AUS, NZ and F)
Size (rear)80/100-21 51R (For EUROPE except F)
Tire pressure (front and rear)110/90-19 62M (For USA, CDN, ZA, AUS, NZ and F)
110/90-19 NHS (For EUROPE except F)
100 kPa (1.0 kgf/cm², 15 psi)
Brake:
Front brake typeSingle disc brake
OperationRight hand operation
Rear brake typeSingle disc brake
OperationRight foot operation
Suspension:
Front suspensionTelescopic fork
Rear suspensionSwingarm (link type monocross suspension)
Shock absorber:
Front shock absorberCoil spring/oil damper
Rear shock absorberCoil spring/gas, oil damper
Wheel travel:
Front wheel travel300 mm (11.8 in)
Rear wheel travel315 mm (12.4 in)
Electrical:
Ignition systemCDI magneto

MAINTENANCE SPECIFICATIONS

ENGINE

ItemStandardLimit
Cylinder head: Warp limit----0.05 mm (0.002 in)
Cylinder: Bore size95.00 ~ 95.01 mm (3.7402 ~ 3.7406 in)----
Out of round limit----0.05 mm (0.002 in)
Camshaft: Drive methodChain drive (Left)----
Camshaft cap inside diameter22.000 ~ 22.021 mm (0.8661 ~ 0.8670 in)----
Camshaft journal diameter21.959 ~ 21.972 mm (0.8645 ~ 0.8650 in)----
Shaft-to-cap clearance0.028 ~ 0.062 mm (0.0011 ~ 0.0024 in)0.08 mm (0.003 in)
Cam dimensions
Intake“A”31.200 ~ 31.300 mm (1.2283 ~ 1.2323 in)
“B”22.550 ~ 22.650 mm (0.8878 ~ 0.8917 in)
Exhaust“A”30.950 ~ 31.050 mm (1.2185 ~ 1.2224 in)
“B”22.494 ~ 22.594 mm (0.8856 ~ 0.8895 in)
Camshaft runout limit----
ItemStandardLimit
Cam chain: Cam chain type/No. of links Cam chain adjustment method98XRH2010-118M/118 Automatic---- ----
Valve, valve seat, valve guide: Valve clearance (cold) Head Diameter AIN EX0.10 ~ 0.15 mm (0.0039 ~ 0.0059 in) 0.20 ~ 0.25 mm (0.0079 ~ 0.0098 in)---- ---- ----
Face WidthSeat WidthMargin Thickness
“A” head diameter BIN EX26.9 ~ 27.1 mm (1.0591 ~ 1.0669 in) 27.9 ~ 28.1 mm (1.0984 ~ 1.1063 in)---- ----
“B” face width CIN EX2.26 mm (0.089 in) 2.26 mm (0.089 in)---- ----
“C” seat width DIN EX0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in) 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)1.6 mm (0.0630 in) 1.6 mm (0.0630 in)
IN EX1 mm (0.0394 in) 1 mm (0.0394 in)0.85 mm (0.033 in) 0.85 mm (0.033 in)
Stem outside diameter EIN EX4.475 ~ 4.490 mm (0.1762 ~ 0.1768 in) 4.965 ~ 4.980 mm (0.1955 ~ 0.1961 in)4.445 mm (0.1750 in) 4.935 mm (0.1943 in)
Guide inside diameter FIN EX4.500 ~ 4.512 mm (0.1772 ~ 0.1776 in) 5.000 ~ 5.012 mm (0.1969 ~ 0.1973 in)4.550 mm (0.1791 in) 5.050 mm (0.1988 in)
Stem-to-guide clearance GIN EX0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in) 0.020 ~ 0.047 mm (0.0008 ~ 0.0019 in)0.08 mm (0.003 in) 0.10 mm (0.004 in)
Stem runout limit----0.01 mm (0.0004 in)
Valve spring:
Free lengthIN37.03 mm (1.46 in)36.03 mm(1.42 in)
EX37.68 mm (1.48 in)36.68 mm(1.44 in)
Set length (valve closed)IN27.87 mm (1.10 in)----
EX27.38 mm (1.08 in)----
Compressed force (installed)IN111.3 ~ 127.9 N at 27.87 mm(11.3 ~ 13.0 kg at 27.87 mm,24.91 ~ 28.66 lb at 1.10 in)----
EX127.4 ~ 146.4 N at 27.38 mm(13.0 ~ 14.9 kg at 27.38 mm,28.66 ~ 32.85 lb at 1.08 in)----
Tilt limit *IN----2.5°/1.61 mm(2.5°/0.063 in)
EX----2.5°/1.65 mm(2.5°/0.065 in)
Direction of winding (top view)INClockwise----
EXClockwise----
Piston:
Piston to cylinder clearance0.040 ~ 0.065 mm(0.0016 ~ 0.0026 in)0.1 mm(0.004 in)
Piston size “D”94.945 ~ 94.960 mm(3.738 ~ 3.739 in)----
Measuring point “H”8 mm (0.315 in)----
Piston off-set1 mm (0.0394 in)----
Piston pin bore inside diameter18.004 ~ 18.015 mm(0.7088 ~ 0.7093 in)18.045 mm(0.7104 in)
Piston pin outside diameter17.991 ~ 18.000 mm(0.7083 ~ 0.7087 in)17.971 mm(0.7075 in)
Piston rings:Top ring:TypeDimensions (B × T)End gap (installed)Side clearance (installed)2nd ring:TypeDimensions (B × T)End gap (installed)Side clearanceOil ring:Dimensions (B × T)End gap (installed)Barrel1.2 × 3.5 mm (0.05 × 0.14 in)0.20 ~ 0.30 mm(0.008 ~ 0.012 in)0.030 ~ 0.065 mm(0.0012 ~ 0.0026 in)--------0.55 mm(0.022 in)0.12 mm(0.005 in)
Taper1.00 × 3.35 mm (0.04 × 0.13 in)0.35 ~ 0.50 mm(0.014 ~ 0.020 in)0.020 ~ 0.055 mm(0.0008 ~ 0.0022 in)--------0.85 mm(0.033 in)0.12 mm(0.005 in)
2.0 × 2.9 mm (0.08 × 0.11 in)0.2 ~ 0.5 mm (0.01 ~ 0.02 in)----
Crankshaft:Crank width “A”Runout limit “C”Big end side clearance “D”Small end free play “F”61.95 ~ 62.00 mm(2.439 ~ 2.441 in)0.03 mm (0.0012 in)0.15 ~ 0.45 mm(0.0059 ~ 0.0177 in)0.4 ~ 1.0 mm (0.02 ~ 0.04 in)----0.05 mm(0.002 in)0.50 mm(0.02 in)2.0 mm(0.08 in)
Balancer:Balancer drive methodGear----
Air filter oil grade:Foam-air-filter oil or equivalentoil----
ItemStandardLimit
Clutch:
Friction plate thickness2.92 ~ 3.08 mm(0.115 ~ 0.121 in)2.8 mm(0.110 in)
Quantity8----
Clutch plate thickness1.5 ~ 1.7 mm (0.059 ~ 0.067 in)----
Quantity7----
Warp limit----0.1 mm(0.004 in)
Clutch spring free length50.0 mm (1.97 in)49.0 mm(1.93 in)
Quantity6----
Clutch housing thrust clearance0.10 ~ 0.35 mm(0.0039 ~ 0.0138 in)----
Clutch housing radial clearance0.010 ~ 0.044 mm(0.0004 ~ 0.0017 in)----
Clutch release methodInner push, cam push----
Shifter:
Shifter typeCam drum and guide bar----
Guide bar bending limit----0.05 mm(0.002 in)
Kick starter:
TypeRatchet type----
Carburetor:
I.D. mark2S27 70----
Main jet(M.J)#160----
Main air jet(M.A.J)ø2.0----
Jet needle - clip position(J.N)NFLR-4----
Cutaway(C.A)1.5----
Pilot jet(P.J)#45----
Pilot air jet(P.A.J)#100----
Pilot outlet(P.O)ø0.9----
Pilot screw (example)(P.S)1-1/4----
Bypass(B.P)ø1.0----
Valve seat size(V.S)ø3.8----
Starter jet(G.S)#72----
Leak jet(Acc. P)#55----
Float height(F.H)8 mm (0.31 in)----
Engine idle speed1,900 ~ 2,100 r/min----
Intake vacuum28.0 ~ 33.3 kPa(210 ~ 250 mmHg,8.27 ~ 9.84 inHg)----
Hot starter lever free play3 ~ 6 mm (0.12 ~ 0.24 in)----
ItemStandardLimit
Lubrication system:
Oil filter typePaper type----
Oil pump typeTrochoid type----
Tip clearance“A”0.12 mm or less0.20 mm
(0.0047 in or less)(0.008 in)
Tip clearance“B”0.09 ~ 0.17 mm0.24 mm
(0.0035 ~ 0.0067 in)(0.009 in)
Side clearance0.03 ~ 0.10 mm0.17 mm
(0.0012 ~ 0.0039 in)(0.007 in)
Bypass valve setting pressure40 ~ 80 kPa (0.4 ~ 0.8 kg/cm2, 5.69 ~ 11.38 psi)----
Cooling:
Radiator core size
Width120.2 mm (4.73 in)----
Height240 mm (9.45 in)----
Thickness22 mm (0.87 in)----
Radiator cap opening pressure110 kPa (1.1 kg/cm2, 15.6 psi)----
Radiator capacity (total)0.56 L (0.49 Imp qt, 0.59 US qt)----
Water pump
TypeSingle-suction centrifugal pump----

YAMAHA YZ450F-2007 - ENGINE - 1

Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
Spark plugM10S × 1.01131.39.4
Camshaft capM6 × 1.010101.07.2
Cylinder head blind plug screwM12 × 1.01282.820
Cylinder head (stud bolt)M8 × 1.251151.511
(bolt)M10 × 1.254Refer to NOTE.*1
(bolt)M6 × 1.02101.07.2
Cylinder head coverM6 × 1.02101.07.2
CylinderM6 × 1.01101.07.2
Timing chain tensionerM6 × 1.02101.07.2
Tensioner cap boltM6 × 1.0170.75.1
Timing chain guide (rear)M6 × 1.02101.07.2
Exhaust pipe (nut)M8 × 1.251202.014
(bolt)M8 × 1.251202.014
SilencerM8 × 1.252303.022
Silencer clampM8 × 1.251141.410
Exhaust pipe protectorM6 × 1.03101.07.2
Carburetor jointM6 × 1.03101.07.2
Carburetor joint clampM4 × 0.7130.32.2
Air filter caseM6 × 1.0280.85.8
Air filter joint clampM6 × 1.0130.32.2
Air filter joint and air filter caseM5 × 0.8140.42.9
Throttle cable adjust bolt and locknutM6 × 0.75140.42.9
Throttle cable (pull)M6 × 1.0140.42.9
Throttle cable (return)M12 × 1.01111.18.0
Throttle cable coverM5 × 0.8240.42.9
Hot starter plungerM12 × 1.0120.21.4
Hot starter cable adjust bolt and locknutM6 × 0.75140.42.9
Air filter elementM6 × 1.0120.21.4
Radiator stayM6 × 1.0670.75.1
RadiatorM6 × 1.04101.07.2
Radiator hose clampM6 × 1.0820.21.4
Radiator pipe 1, 2M6 × 1.02101.07.2
ImpellerM8 × 1.251141.410
Water pump housing coverM6 × 1.03101.07.2
Coolant drain boltM6 × 1.01101.07.2
Oil pump coverM4 × 0.7120.21.4
Oil pumpM6 × 1.02101.07.2
Oil pump drive gear shaftM6 × 1.01101.07.2
Engine oil drain bolt (oil filter)M6 × 1.01101.07.2
Oil filter coverM6 × 1.02101.07.2
Oil check bolt (cylinder head)M6 × 1.01101.07.2
Oil hose clamp220.21.4
Clutch coverM6 × 1.07101.07.2
Crankcase cover (right)M6 × 1.08101.07.2
M6 × 1.02121.28.7
Crankcase cover (left)M6 × 1.08101.07.2
CrankcaseM6 × 1.012121.28.7
Clutch cable holderM6 × 1.02101.07.2
Oil drain bolt (crankcase right)M10 × 1.251202.014
(crankcase left)M8 × 1.251202.014
Oil check bolt (crankcase)M6 × 1.01101.07.2
Oil strainerM6 × 1.01101.07.2
Crankcase bearing stopperM6 × 1.04141.410
Crankcase bearing stopperM6 × 1.08101.07.2
Drive axle oil seal stopperM6 × 1.02101.07.2
Ratchet wheel guideM6 × 1.02121.28.7
Kick starterM8 × 1.251333.324
Screw (kick starter)M6 × 1.0170.75.1
Primary drive gearM20 × 1.0111011.080
Clutch bossM20 × 1.01757.554
Clutch cable adjust bolt and locknutM6 × 0.75140.42.9
Clutch springM6 × 1.06101.07.2
BalancerM10 × 1.01454.532
Balancer driven gearM14 × 1.01505.036
Balancer weight plateM6 × 1.03101.07.2
Drive sprocketM20 × 1.01757.554
Drive sprocket coverM6 × 1.0280.85.8
Shift pedalM6 × 1.01121.28.7
Shift guideM6 × 1.02101.07.2
Stopper leverM6 × 1.01101.07.2
SegmentM8 × 1.251303.022

NOTE:

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

NOTE:

*1: Tighten the cylinder head bolts to 30 Nm (3.0 m • kg, 22 ft • lb) in the proper tightening sequence, remove and retighten the cylinder head bolts to 20 Nm (2.0 m • kg, 14 ft • lb) in the proper tightening sequence, and then tighten the cylinder head bolts further to reach the specified angle 180^ in the proper tightening sequence.

EC212201

CHASSIS

ItemStandardLimit
Steering system: Steering bearing typeTaper roller bearing----
Front suspension:USA, CDN, AUS, NZ, ZAEUROPE
Front fork travel300 mm (11.8 in)----
Fork spring free length454 mm (17.9 in)449 mm (17.7 in)
Spring rate, STDK = 4.6 N/mm (0.469 kg/mm, 26.3 lb/in)----
Optional springYes----
Oil capacity527 cm³ (18.6 Imp oz, 17.8 US oz)537 cm³ (18.9 Imp oz, 18.2 US oz)----
Oil gradeSuspension oil "S1"----
Inner tube outer diameter48 mm (1.89 in)----
Front fork top endZero mm (Zero in)----
Rear suspension:USA, CDN, AUS, NZ, ZAEUROPE
Shock absorber travel131.5 mm (5.18 in)----
Spring free lengthApprox. 275 mm (10.83 in)----
Fitting length
One I.D. mark266 mm (10.47 in)268 mm (10.55 in)----
Two I.D. marks272 mm (10.71 in)274 mm (10.79 in)----
Three I.D. marks263.5 mm (10.37 in)265.5 mm (10.45 in)----
<Min..~Max.>
One I.D. mark255.5 ~ 273.5 mm (10.06 ~ 10.77 in)----
Two I.D. marks261.5 ~ 279.5 mm (10.30 ~ 11.00 in)----
Three I.D. marks253.0 ~ 271.0 mm (9.96 ~ 10.67 in)----
Spring rate, STDK = 54.0 N/mm (5.50 kg/mm, 308.0 lb/in)----
Optional springYes----
Enclosed gas pressure1,000 kPa (10 kg/cm², 142 psi)----

MAINTENANCE SPECIFICATIONS

SPEC
ItemStandardLimit
Swingarm: Swingarm free play limit End----1.0 mm (0.04 in)
Wheel: Front wheel typeSpoke wheel----
Rear wheel typeSpoke wheel----
Front rim size/material21 × 1.60/Aluminum----
Rear rim size/material19 × 2.15/Aluminum----
Rim runout limit: Radial----2.0 mm (0.08 in)
Lateral----2.0 mm (0.08 in)
Drive chain: Type/manufacturerDID520DMA2 SDH/DAIDO----
Number of links113 links + joint----
Chain slack48 ~ 58 mm (1.9 ~ 2.3 in)----
Chain length (15 links)----242.9 mm (9.563 in)
Front disc brake: Disc outside dia. × Thickness250 × 3.0 mm (9.84 × 0.12 in)250 × 2.5 mm (9.84 × 0.10 in)
Pad thickness4.4 mm (0.17 in)1.0 mm (0.04 in)
Master cylinder inside dia.11.0 mm (0.433 in)----
Caliper cylinder inside dia.27.0 mm (1.063 in) × 2----
Brake fluid typeDOT #4----
Rear disc brake: Disc outside dia. × Thickness245 × 4.0 mm (9.65 × 0.16 in)245 × 3.5 mm (9.65 × 0.14 in)
Deflection limit----0.15 mm (0.006 in)
Pad thickness6.4 mm (0.25 in)1.0 mm (0.04 in)
Master cylinder inside dia.11.0 mm (0.433 in)----
Caliper cylinder inside dia.25.4 mm (1.000 in) × 1----
Brake fluid typeDOT #4----
Brake lever and brake pedal: Brake lever position95 mm (3.74 in)----
Brake pedal height (vertical height above footrest top)5 mm (0.20 in)----
Clutch lever free play (lever end)8 ~ 13 mm (0.31 ~ 0.51 in)----
Throttle grip free play3 ~ 5 mm (0.12 ~ 0.20 in)----
Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
Handle crown and outer tubeM8 × 1.254212.115
Under bracket and outer tubeM8 × 1.254212.115
Handle crown and steering shaftM24 × 1.0114514.5105
Handlebar holder (upper)M8 × 1.254282.820
Handlebar holder (lower)M10 × 1.252343.424
Steering ring nutM28 × 1.01Refer to NOTE.
Front fork and damper assemblyM51 × 1.52303.022
Front fork and adjusterM22 × 1.252555.540
Damper assembly and base valveM42 × 1.52292.921
Adjuster and damper assemblyM12 × 1.252292.921
Bleed screw (front fork) and base valveM5 × 0.8210.10.7
Front fork and protectorM6 × 1.0670.75.1
Protector and brake hose holderM6 × 1.0270.75.1
Throttle cable capM5 × 0.8240.42.9
Clutch lever holder mountingM5 × 0.8240.42.9
Clutch lever mounting (nut)M6 × 1.0140.42.9
Hot starter lever holder mountingM5 × 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 × 1.0160.64.3
Brake lever mounting (nut)M6 × 1.0160.64.3
Brake lever position locknutM6 × 1.0150.53.6
Cable guide (front brake hose) and under bracketM6 × 1.0140.42.9
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 × 1.252232.317
Front brake caliper and brake hose holderM6 × 1.01101.07.2
Brake caliper (front and rear) and pad pin plugM10 × 1.0230.32.2
Brake caliper (front and rear) and pad pinM10 × 1.02181.813
Brake caliper (front and rear) and bleed screwM8 × 1.25260.64.3
Front wheel axle and nutM16 × 1.5110510.575
Front wheel axle holderM8 × 1.254212.115
Front brake disc and wheel hubM6 × 1.06121.28.7
Rear brake disc and wheel hubM6 × 1.06141.410
Footrest bracket and frameM10 × 1.254555.540
Brake pedal mountingM8 × 1.251262.619
Rear brake master cylinder and frameM6 × 1.02101.07.2
Rear brake master cylinder capM4 × 0.7220.21.4
Rear brake hose union bolt (caliper)M10 × 1.251303.022
Rear brake hose union bolt (master cylinder)M10 × 1.251303.022

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).

Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
Rear wheel axle and nutM20 × 1.5112512.590
Driven sprocket and wheel hubM8 × 1.256424.230
Nipple (spoke)7230.32.2
Disc cover and rear brake caliperM6 × 1.02101.07.2
Protector and rear brake caliperM6 × 1.0270.75.1
Chain puller adjust bolt and locknutM8 × 1.252191.913
Engine mounting:
Engine upper bracket and frameM10 × 1.254555.540
Engine lower bracket and frameM8 × 1.254343.424
Engine and engine bracket (front)M10 × 1.251535.338
Engine and engine bracket (upper)M10 × 1.251555.540
Engine and frame (lower)M10 × 1.251535.338
Engine guardM6 × 1.01101.07.2
Engine skid plate mountingM6 × 1.03101.07.2
CDI unit bracket mountingM6 × 1.0270.75.1
Cable guide and CDI unit bracketM5 × 0.8240.42.9
Cable guide and frameM5 × 0.8150.53.6
Pivot shaft and nutM16 × 1.51858.561
Relay arm and swingarmM14 × 1.51707.050
Relay arm and connecting rodM14 × 1.51808.058
Connecting rod and frameM14 × 1.51808.058
Rear shock absorber and frameM10 × 1.251565.640
Rear shock absorber and relay armM10 × 1.251535.338
Rear frame and frame (upper)M8 × 1.251323.223
Rear frame and frame (lower)M8 × 1.252323.223
Swingarm and brake hose holderM5 × 0.8420.21.4
Swingarm and patchM4 × 0.7420.21.4
Drive chain tensioner mounting (upper)M8 × 1.251161.611
Drive chain tensioner mounting (lower)M8 × 1.251161.611
Chain support and swingarmM6 × 1.0370.75.1
Seal guard and swingarmM5 × 0.8460.64.3
Fuel tank mounting boss and frameM10 × 1.251202.014
Fuel tank mountingM6 × 1.0290.96.5
Fuel tank and fuel cockM6 × 1.0240.42.9
Fuel tank and seat set bracketM6 × 1.0170.75.1
Fuel tank and fuel tank bracketM6 × 1.0470.75.1
Seat mountingM8 × 1.252232.317
Side cover mountingM6 × 1.0270.75.1
Air scoop and fuel tankM6 × 1.0670.75.1
Air scoop and radiator panel (lower)M6 × 1.0270.75.1
Front fender mountingM6 × 1.0470.75.1
Rear fender mounting (front)M6 × 1.0270.75.1
Rear fender mounting (rear)M6 × 1.02161.611
Number plateM6 × 1.0170.75.1

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

EC212300

ELECTRICAL

ItemStandardLimit
Ignition system: Advancer typeElectrical----
C.D.I.: Magneto-model (stator)/manufacturer2S200/YAMAHA----
Source coil 1 resistance (color)720 ~ 1,080 Ω at 20 °C (68 °F) (Green – Brown)----
Source coil 2 resistance (color)44 ~ 66 Ω at 20 °C (68 °F) (Black – Pink)----
Pickup coil resistance (color)248 ~ 372 Ω at 20 °C (68 °F) (White – Red)----
CDI unit-model/manufacturer2S2-70/YAMAHA (Except for EUROPE)----
2S2-80/YAMAHA (For EUROPE)----
Ignition coil: Model/manufacturer5TA-10/DENSO----
Minimum spark gap6 mm (0.24 in)----
Primary winding resistance0.08 ~ 0.10 Ω at 20 °C (68 °F)----
Secondary winding resistance4.6 ~ 6.8 kΩ at 20 °C (68 °F)----
Part to be tightenedThread sizeQ'tyTightening torque
Nmm·kgft·lb
StatorM6 × 1.03101.07.2
RotorM12 × 1.251565.640
Neutral switchM5 × 0.8240.42.9

EC220001

GENERAL TORQUE SPECIFICATIONS

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

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

YAMAHA YZ450F-2007 - GENERAL TORQUE SPECIFICATIONS - 1

A: Distance between flats
B: Outside thread diameter

EC230000

DEFINITION OF UNITS

UnitReadDefinitionMeasure
mmmillimeter10-3meterLength
cmcentimeter10-2meterLength
kgkilogram103gramWeight
NNewton1 kg × m/sec2Force
NmNewton meterN × mTorque
m • kgMeter kilogramm × kgTorque
PaPascalN/m2Pressure
N/mmNewton per millimeterN/mmSpring rate
LLiterVolume or capacity
cm3Cubic centimeterVolume or capacity
r/minRevolution per minuteEngine speed

CHARACTERISTIQUES

CHARACTERISTIQUES GENERALES

LUBRICATION DIAGRAMS

① Oil filter element
② Oil pump
③ Drive axle
④ Main axle
⑤ Crankshaft
⑥ Connecting rod
A From cylinder
To oil tank

YAMAHA YZ450F-2007 - LUBRICATION DIAGRAMS - 1

DIAGRAMMES DE LUBRIFICATION

① Intake camshaft
② Exhaust camshaft
A To main axle
From oil pump

YAMAHA YZ450F-2007 - DIAGRAMMES DE LUBRIFICATION - 1

DIAGRAMMES DE LUBRIFICATION SCHMIERSYSTEM-SCHAUBILDER

YAMAHA YZ450F-2007 - DIAGRAMMES DE LUBRIFICATION SCHMIERSYSTEM-SCHAUBILDER - 1

① Fuel tank breather hose
② Radiator hose 1
③ Cylinder head breather hose
(4) Hose holder
(5) Radiator hose 4
⑥ Clutch cable
⑦ Connector cover
(8) Fuel hose
TPS (throttle position sensor) lead
Hot starter cable
① Carburetor breather hose
⑫ Carburetor overflow hose

A Insert the end of the fuel tank breather hose into the hole in the steering shaft.
Pass the cylinder head breather hose on the outside of the radiator hose 1 and between the radiator hose 4 and frame.
Align the paint on the cylinder head breather hose with the front edge of the hose holder.
Pass the clutch cable through the cable guide.

Pass the clutch cable in front of the radiator mounting boss.
Install the connector cover so that it does not come in between the radiator hose 1 and radiator.
Pass the fuel hose between the hot starter cable and TPS lead.
Pass the carburetor breather hoses and overflow hose so that all there hoses do not contact the rear shock absorber.

YAMAHA YZ450F-2007 - DIAGRAMMES DE LUBRIFICATION SCHMIERSYSTEM-SCHAUBILDER - 2

DIAGRAMME

D'ACHEMINEMENT DES CABLES

① Hot starter cable
② Clamp
③ TPS (throttle position sensor) lead
Hump (frame)
Neutral switch lead
⑥ Engine bracket
⑦ Engine skid plate stay
⑧ CDI magneto lead
⑨ Clutch cable
⑩ Radiator breather hose
① Radiator hose 2
⑫“ENGINE STOP” button lead

13 Sub wire harness
⑭ Ground lead
CDI unit bracket
16 CDI unit
⑦ Cable guide
忍 Ignition coil lead
Throttle cable

A Fasten the hot starter cable and throttle cables onto the frame. Locate the clamp ends under the hot starter cable.

Fasten the hot starter cable, throttle cables, TPS lead and ignition coil lead to the frame.
Fasten the TPS lead to the frame behind its hump.
Pass the TPS lead over the hot starter cable.
Pass the neutral switch lead on the inside of the engine bracket.
Pass the neutral switch lead over the engine skid plate stay.

YAMAHA YZ450F-2007 - D'ACHEMINEMENT DES CABLES - 1

DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME

Fasten the neutral switch lead and radiator breather hose to the frame.
Fasten the neutral switch lead, CDI magneto lead and radiator breather hose to the frame.
Fasten the neutral switch lead, CDI magneto lead, radiator breather hose and clutch cable to the frame over the radiator mounting boss.

Pass the radiator breather hose in front of the radiator hose 2, on the left of the chassis, and then between the frame and radiator hose 4.
Fasten the sub wire harness and "ENGINE STOP" button lead to the CDI unit bracket with the clamp ends facing downward behind the location where the ground lead branches out from the sub wire harness.

Fasten the ground lead and cable guide together to the CDI unit bracket.
MLocate the clamp ends in the arrowed range.
Fasten the neutral switch lead and CDI magneto lead to the frame over its hump.

YAMAHA YZ450F-2007 - DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME - 1

DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME

① Throttle cable (pull)
② Throttle cable (return)
③ Radiator hose 2
④ Ignition coil
⑤ Rear arm bracket
⑥ Cylinder head breather hose

A Pass the throttle cables over the radiator hose 2.
Pass the throttle cables on the outside of the ignition coil.
Fasten the throttle cables with the clamp so that the cables are not bent, and pass them under the rear arm bracket.
Pass the cylinder head breather hose so that it does not contact the ignition coil.

YAMAHA YZ450F-2007 - DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME - 1
A

YAMAHA YZ450F-2007 - DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME - 2

YAMAHA YZ450F-2007 - DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME - 3
B

DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME

① Master cylinder
② Brake hose holder
③ Brake hose

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

YAMAHA YZ450F-2007 - DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME - 1

YAMAHA YZ450F-2007 - DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME - 2

A Fasten the "ENGINE STOP" button lead to the handlebar.
Pass the clutch cable and hot starter cable through the cable guide.
Pass the brake hose in front of the number plate.
Pass the throttle cables through the cable guide.
Pass the clutch cable and hot starter cable through the cable guide on the number plate.

YAMAHA YZ450F-2007 - DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME - 3

DIAGRAMME D'ACHEMINEMENT DES CABLES KABELFUHRUNGSDIAGRAMME

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
VALVES Check the valve clearancesThe engine must be cold. Check the valve seats and valve stems for wear.
Inspect Replace
VALVE SPRINGS Inspect ReplaceCheck the free length and the tilt.
VALVE LIFTERS Inspect Replace
CAMSHAFTS Inspect Replace
CAMSHAFT SPROCKETS Inspect Replace
PISTON Inspect Clean Replace
PISTON RING Inspect Replace
PISTON PIN Inspect Replace
CYLINDER HEAD Inspect and clean
CYLINDER Inspect and clean Replace
CLUTCH Inspect and adjust Replace
TRANSMISSION Inspect Replace bearing
SHIFT FORK, SHIFT CAM, GUIDE BAR InspectInspect wear
ROTOR NUT Retighten
MUFFLER Inspect and retighten* Whichever comes first
Clean Replace
CRANK Inspect and clean
CARBURETOR Inspect, adjust and clean
SPARK PLUG Inspect and clean Replace
DRIVE CHAIN Lubricate, slack, alignment ReplaceUse chain lube Chain slack: 48 ~ 58 mm (1.9 ~ 2.3 in)
COOLING SYSTEM Check coolant level and leakage Check radiator cap operation Replace coolant Inspect hosesEvery 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 or equivalent oil
OIL FILTER Replace
FRAME Clean and inspect
FUEL TANK, COCK Clean and inspect
BRAKES Adjust lever position and pedal height Lubricate pivot point Check brake disc surface Check fluid level and leakage Retighten brake disc bolts, caliper bolts, master cylinder bolts and union bolts Replace pads Replace brake fluid●●●●●
●●Every one year
FRONT FORKS Inspect and adjust Replace oil Replace oil seal●●Suspension oil "S1"

MAINTENANCE INTERVALS

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
PROTECTOR GUIDE Replace
REAR SHOCK ABSORBER Inspect and adjust Lube(After rain ride)Molybdenum disulfide grease Every one year
Replace spring seat Retighten
CHAIN GUARD AND ROLLERS Inspect
SWINGARM Inspect, lube and retightenMolybdenum disulfide grease
RELAY ARM, CONNECTING ROD Inspect, lube and retightenMolybdenum disulfide grease
STEERING HEAD Inspect free play and retightenLithium base grease
Clean and lube Replace bearing
TIRE, WHEELS Inspect air pressure, wheel run-out, tire wear and spoke looseness Retighten sprocket bolt Inspect bearings Replace bearings LubricateLithium base grease
THROTTLE,CONTROL CABLE Check routing and connection LubricateYamaha cable lube or SAE 10W-30 motor oil
HOT STARTER,CLUTCH LEVER Inspect free play

CONTROLES ET REGLAGES PERIODIQUES

PROGRAMME D'ENTRETIEN

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

Before using this machine, check the following points.

GENERAL INSPECTION AND MAINTENANCE

ItemRoutinePage
CoolantCheck that coolant is filled up to the radiator filler cap. 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.1-13
Engine oilCheck that the oil level is correct. Check the crankcase and 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 ~ 10
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
BrakesCheck the play of front brake and effect of front and rear brake.P.3-24 ~ 30
ChainCheck chain slack and alignment. Check that the chain is lubricated properly.P.3-31 ~ 33
WheelsCheck for excessive wear and tire pressure. Check for loose spokes and have no excessive play.P.3-41 ~ 42
SteeringCheck that the handlebar can be turned smoothly and have no excessive play.P.3-42 ~ 44
Front forks and rear shock absorberCheck that they operate smoothly and there is no oil leakage.P.3-33 ~ 40
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.
MufflerCheck that the muffler is tightly mounted and has no cracks.
SprocketCheck that the driven sprocket tightening bolt is not loose.P.3-31
LubricationCheck for smooth operation. Lubricate if necessary.P.3-45
Bolts and nutsCheck the chassis and engine for loose bolts and nuts.P.1-18
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are connected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course and weather or by taking into account the results of test runs before racing? Are inspection and maintenance completely done?P.7-1 ~ 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.

YAMAHA YZ450F-2007 - CAUTION: - 1

  1. Place the machine on a level place, and hold it in an upright position.
  2. Remove:

  3. Radiator cap

  4. Check:
    Coolant level ⑧

Coolant level low Add coolant.

① Radiator

MOTEUR

CONTROLE DU Niveau DU LIQUIDE DE REFROIDISSEMENT

AVERTISSEMENT

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

CAUTION:

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

YAMAHA YZ450F-2007 - CAUTION: - 1

YAMAHA YZ450F-2007 - CAUTION: - 2

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

  3. Engine guard ①
    Coolant drain bolt ②

  4. Remove:

  5. Radiator cap

Drain the coolant completely.

  1. Clean:

  2. Cooling system

Thoroughly flush the cooling system with clean tap water.

  1. Install:

  2. Plain washer
    Coolant drain bolt

YAMAHA YZ450F-2007 - CAUTION: - 3

10 Nm (1.0 m · kg, 7.2 ft · lb)

  • Engine guard
  • Bolt (engine guard)

YAMAHA YZ450F-2007 - CAUTION: - 4

10 Nm (1.0 m·kg, 7.2 ft·lb)

  1. Fill:

  2. Radiator

  3. Engine

To specified level.

YAMAHA YZ450F-2007 - CAUTION: - 5

Recommended coolant: High quality ethylene glycol anti-freeze containing anticorrosion for aluminum engine Coolant ① and water (soft water) ② mixing ratio: 50 % / 50 % Coolant capacity: 0.99 L (0.87 Imp qt, 1.05 US qt)

CHANGEMENT DU LIQUIDE DE REFROIDISSEMENT

AVERTISSEMENT

  • 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.

  • Install:

  • Radiator cap

Start the engine and warm it up for a several minutes.

  1. Check:

Coolant level

Coolant level low Add coolant.

YAMAHA YZ450F-2007 - WARNING - 1

EC:355000

RADIATOR CAP INSPECTION

  1. Inspect:

  2. Seal (radiator cap) ①

  3. Valve and valve seat ②

Crack/damage Replace.

Exist fur deposits ③ Clean or replace.

ATTENTION:

  1. Attach:

  2. Radiator cap tester ① and adapter ②

YAMAHA YZ450F-2007 - ATTENTION: - 1

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

Adapter: YU-33984/90890-01352

NOTE:

Apply water on the radiator cap seal.

③ Radiator cap

  1. Apply the specified pressure.

YAMAHA YZ450F-2007 - 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 YZ450F-2007 - NOTE: - 2

EC357002 COOLING SYSTEM INSPECTION

  1. Inspect:

Coolant level

  1. Attach:

  2. Radiator cap tester ① and adapter ②

YAMAHA YZ450F-2007 - EC357002 COOLING SYSTEM INSPECTION - 1

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

Adapter: YU-33984/90890-01352

  1. Apply the specified pressure.

YAMAHA YZ450F-2007 - EC357002 COOLING SYSTEM INSPECTION - 2

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

CONTROLE DE LA PRESSION D'OUVERTURE DU BOUCHON DE 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.

YAMAHA YZ450F-2007 - Inspect: - 1

YAMAHA YZ450F-2007 - Inspect: - 2

EC359020

CLUTCH ADJUSTMENT

1. Check:

  • Clutch lever free play @

Out of specification Adjust.

YAMAHA YZ450F-2007 - Check: - 1

Clutch lever free play ④ : 8 ~ 13 mm (0.31 ~ 0.51 in)

2. Adjust:

  • Clutch lever free play

Clutch lever free play adjustment steps:

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

YAMAHA YZ450F-2007 - Clutch lever free play adjustment steps: - 1

Locknut: 4 Nm (0.4 m • kg, 2.9 ft • lb)

NOTE:

  • Before adjustment, expose the adjuster by moving the boot ③ and cap ④ away.
  • Make minute adjustment on the lever side using the adjuster ⑤.
  • After adjustment, check proper operation of clutch lever.

N.B.:

Place the tip ⑧ of the cap in the boot.

EC35A001

THROTTLE CABLE ADJUSTMENT

  1. Check:

  2. Throttle grip free play ⑧

Out of specification Adjust.

YAMAHA YZ450F-2007 - THROTTLE CABLE ADJUSTMENT - 1

Throttle grip free play @:

3 5 ~mm (0.12 ~ 0.20 in)

  1. Adjust:

  2. Throttle grip free play

YAMAHA YZ450F-2007 - THROTTLE CABLE ADJUSTMENT - 2

le grip free play adjustment steps:

  • Slide the adjuster cover.
  • Loosen the locknut ①.
  • Turn the adjuster ② until the specified free play is obtained.
  • Tighten the locknut.

YAMAHA YZ450F-2007 - THROTTLE CABLE ADJUSTMENT - 3

Locknut: 4 Nm (0.4 m • kg, 2.9 ft • lb)

NOTE:

Before adjusting the throttle cable free play, the engine idle speed should be adjusted.

WARNING

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

YAMAHA YZ450F-2007 - WARNING - 1

THROTTLE LUBRICATION

  1. Remove:

  2. Cover (throttle cable cap) ①

  3. Cover (grip cap) ②
  4. Throttle cable cap ③

  5. Monter:

  6. Bouchon ①

  7. Manchon ②

N.B.:

  • Lithium soap base grease On the throttle cable end (a).

3. Install:

  • Throttle cable cap
  • Screw (throttle cable cap)

4 Nm (0.4 m·kg, 2.9 ft·lb)

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

HOT STARTER LEVER ADJUSTMENT

1. Check:

  • Hot starter lever free play ④ Out of specification Adjust.

YAMAHA YZ450F-2007 - Check: - 1

Hot starter lever free play ④ : 3 ~ 6 mm (0.12 ~ 0.24 in)

2. Adjust:

  • Hot starter lever free play
Hot starter lever free play adjustment steps: ·Loosen the locknut ①. ·Turn the adjuster ② until free play ⑧ is within the specified limits. ·Tighten the locknut.
Locknut: 4 Nm (0.4 m • kg, 2.9 ft • lb)

NOTE:

After adjustment, check proper operation of hot starter.

EC35G040

AIR FILTER CLEANING

NOTE:

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

CAUTION:

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

1. Remove:

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.

  • Inspect:

Air filter element

Damage Replace.

  1. Apply:
  2. Foam-air-filter oil or equivalent oil to the element.

NOTE:

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

YAMAHA YZ450F-2007 - CAUTION: - 1

  1. Install:

  2. Filter guide ①

NOTE:

Align the projection ⑧ on filter guide with the hole ⑥ in air filter element.

YAMAHA YZ450F-2007 - CAUTION: - 2

Air filter element ①
- Washer
Fitting bolt 2Nm (0.2 m·kg, 1.4 ft·lb)

NOTE:

Align the projection ⑧ on filter guide with the hole ⑥ in air filter case.

ENGINE OIL LEVEL INSPECTION

  1. Stand the machine on a level surface.

NOTE:

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

YAMAHA YZ450F-2007 - ENGINE OIL LEVEL INSPECTION - 1

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 machine upright. Then stop the engine and inspect the oil level.

YAMAHA YZ450F-2007 - WARNING - 1

  1. Remove:

  2. Oil tank cap ①

CONTROLE DU NIVEAU D'HUILE MOTEUR MOTORÖLSTAND KONTROLLIEREN

7. Monter:

Check that the engine oil is above the level mark ⑧ and that the oil does not come out when the check bolt ① is removed.

Below the level mark (a) Add oil through the filler cap hole until it is above the level mark (a) .

Oil comes out at the check bolt Drain the oil until it stops coming out.

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 YZ450F-2007 - NOTE: - 1

Recommended oil:
Yamalube 4, SAE10W30 or SAE 20W40
Yamalube 4-R, SAE10W50
API service SG type or high JASO standard MA

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 YZ450F-2007 - CAUTION: - 1

Recommended oil:
SAE10W30, SAE10W40,
SAE15W40, SAE20W40 or
SAE20W50
API service SG type or higher
JASO standard MA

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.

4. Controller:

  • Niveau d'huile

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

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

  3. Oil tank cap

YAMAHA YZ450F-2007 - Controller: - 1

YAMAHA YZ450F-2007 - Controller: - 2

YAMAHA YZ450F-2007 - Controller: - 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:

  4. Oil tank plug ①

  5. Oil filler cap ②
  6. Drain bolt (with gasket) ③
  7. Oil filter drain bolt (O-ring) ④
  8. Drain bolt (with gasket) ⑤ Drain the crankcase and oil tank of its oil.

  9. Mettre le moteur en marche et le laisser chauffer pendant quelques minutes.

ATTENTION:

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

Replacement steps:

  • Remove the oil filter 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.

YAMAHA YZ450F-2007 - Replacement steps: - 1

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

  1. Install:

  2. Gaskets
    New

  3. Oil filter drain bolt

10 Nm (1.0 m · kg, 7.2 ft · lb)

  • Drain bolt (crankcase right)
    20 Nm (2.0 m · kg, 14 ft · lb)
  • Drain bolt (crankcase left)
    20 Nm (2.0 m · kg, 14 ft · lb)

YAMAHA YZ450F-2007 - Replacement steps: - 2

  1. Fill:

Engine oil

YAMAHA YZ450F-2007 - Replacement steps: - 3

Oil quantity:
Periodic oil change:
0.95 L (0.84 Imp qt, 1.00 US qt)
With oil filter replacement:
1.0 L (0.88 Imp qt, 1.06 US qt)
Total amount:
1.2 L (1.06 Imp qt, 1.27 US qt)

CHANGEMENT DE L'HUILE MOTEUR MOTORÖL WECHSELN

  1. Install:

  2. Oil filler cap

  3. Inspect:

  4. Engine (for oil leaks)
    Oil level

Refer to "ENGINE OIL LEVEL INSPECTION".

YAMAHA YZ450F-2007 - CHANGEMENT DE L'HUILE MOTEUR MOTORÖL WECHSELN - 1

  1. Check:

  2. 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 YZ450F-2007 - Checking steps: - 1

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

YAMAHA YZ450F-2007 - Checking steps: - 2

PILOT SCREW ADJUSTMENT

  1. Adjust:

  2. Pilot screw 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 YZ450F-2007 - NOTE: - 1

Pilot screw (example): 1-1/4 turns out

IDLE SPEED ADJUSTMENT

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

  3. Idle speed

Adjustment steps:

  • Adjust the pilot screw.
    Refer to "PILOT SCREW ADJUSTMENT" section.
  • Turn the throttle stop screw ① until the specified engine idling speed.

NOTE:

Using a digital engine tachometer for idle speed adjustment, detect the engine idling speed by bringing the sensing element © of the engine tachometer close to the ignition coil ②.

To increase idle speed

Turn the throttle stop screw ① in ⑧

To decrease idle speed

Turn the throttle stop screw ① out

YAMAHA YZ450F-2007 - NOTE: - 1

Engine idling speed: 1,900 ~ 2,100 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
  • Fuel tank

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

2. Remove:

  • Spark plug
  • Engine upper bracket
  • Hot starter plunger Refer to "CARBURETOR" section in the CHAPTER 4.
  • Cylinder head cover Refer to "CAMSHAFTS" section in the CHAPTER 4.
  • Timing plug ①
  • Straight plug ②
  • O-ring

4. Check:

  • Valve clearance

Out of specification Adjust.

YAMAHA YZ450F-2007 - Check: - 1

Valve clearance (cold):

Intake valve:

0.10 ~ 0.15 mm

(0.0039 ~ 0.0059 in)

Exhaust valve:

0.20 ~ 0.25 mm

(0.0079 ~ 0.0098 in)

Checking steps:

  • Turn the crankshaft counterclockwise with a wrench.
  • 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:

In order to be sure that the piston is at Top Dead Center, the punch mark ⑥ on the exhaust camshaft and the punch mark ⑧ on the intake camshaft must align with the cylinder head surface, as shown in the illustration.

  • Measure the valve clearance ⑥ using a feeler gauge ①.

NOTE:

Record the measured reading if the clearance is incorrect.

  • 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 (exhaust ① and intake ②).

NOTE:

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

  • Remove the valve lifters ④ and the pads ⑤ .

NOTE:

  • Place a rag in the timing chain space to prevent pads from falling into the crank-case.
  • Identity each valve lifter and pad position very carefully so that they can be reinstalled in their original place.
  • Select the proper pad using the pad selecting table.
Pad rangePad Availability: 25 increments
No. 120 ~ No. 2401.20 mm ~ 2.40 mmPads are available in 0.05 mm increments

NOTE:

The thickness ⑧ 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, 1 or 20
4, 5 or 65
8 or 910

EXAMPLE:

Installed pad number = 148

Rounded off value = 150

NOTE:

Pads can only be selected in 0.05mm 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 ⑥ and the valve lifters ⑦ .

NOTE:

  • Apply the engine oil on the valve lifters.
  • Apply the molybdenum disulfide oil on the valve stem ends.
  • Valve lifter must turn smoothly when rotated with a finger.
  • Be careful to reinstall valve lifters and pads in their original place.
  • Install the camshafts (exhaust and intake), the timing chain and the camshaft caps. Refer to "CAMSHAFTS" section in the CHAPTER 4.

YAMAHA YZ450F-2007 - NOTE: - 1

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

  • Install the timing chain tensioner.

Refer to "CAMSHAFTS" section in the CHAPTER 4.

NOTE:

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.

  • Install:

  • All removed parts

NOTE:

Install all removed parts in reversed order of their removal.

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 bled.

  1. Remove:

  2. Master cylinder cap

  3. Diaphragm
  4. Reservoir float (front brake)
  5. Protector (rear brake)

  6. Bleed:

  7. 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 YZ450F-2007 - 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.

CHÂSSIS

PURGE D'AIR DU CIRCUIT 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.

YAMAHA YZ450F-2007 - A VERTISSEMENT - 1

WARNING

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

3. Install:

  • Protector (rear brake)
  • Reservoir float (front brake)
  • Diaphragm
  • Master cylinder cap

YAMAHA YZ450F-2007 - Install: - 1

YAMAHA YZ450F-2007 - Install: - 2

EC362040

  • Brake lever position @
Brake lever position @:
Standard positionExtent of adjustment
95 mm (3.74 in)76 ~ 97 mm (2.99 ~ 3.82 in)

2. Remove:

  • Lever cover

3. Adjust:

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

4. Install:

  • Lever cover

N.B.:

  1. Check:

  2. Brake pedal height @

Out of specification Adjust.

YAMAHA YZ450F-2007 - N.B.: - 1

Brake pedal height ① : 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 ⑧ is within specified height.
  • Tighten the locknut.

WARNING

  • Adjust the pedal height between the maximum A and the minimum B as shown. (In this adjustment, the bolt ③ end ⑥ should protrude out of the threaded portion ④ but not be less than 2 mm (0.08 in) ⑨ 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.

Brake pad thickness @:
Standard<Limit>
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. Controller:

  • Loosen the pad pin ②.
  • Remove the caliper ③ from the front fork.
  • Remove the pad pin and brake pads ④.
  • Connect the transparent hose ⑤ to the bleed screw ⑥ 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 YZ450F-2007 - Do not reuse the drained brake fluid. - 1

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

  • Install the brake pads ⑦ and pad pin.

NOTE:

Install the brake pads with their projections into the caliper recesses 6.
- Temporarily tighten the pad pin at this point.
Install the caliper ⑧ and tighten the pad pin ⑨

YAMAHA YZ450F-2007 - NOTE: - 1

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

Install the pad pin plug ⑩.

YAMAHA YZ450F-2007 - NOTE: - 2

Pad pin plug: 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 YZ450F-2007 - NOTE: - 3

EC366060

REAR BRAKE PAD INSPECTION AND REPLACEMENT

  1. Inspect:

  2. Brake pad thickness @

Out of specification Replace as a set.

YAMAHA YZ450F-2007 - REAR BRAKE PAD INSPECTION AND REPLACEMENT - 1

YAMAHA YZ450F-2007 - REAR BRAKE PAD INSPECTION AND REPLACEMENT - 2

  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 YZ450F-2007 - Brake pad replacement steps: - 1

  • 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 YZ450F-2007 - 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 ⑧ into the caliper recesses 6
- 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 YZ450F-2007 - NOTE: - 1

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

  • Install the pad pin plug ⑤ and protector ⑥ .

YAMAHA YZ450F-2007 - NOTE: - 2

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

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

Boulon (protection):

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 INSPECTION AND REPLACEMENT" section.

  1. Inspect:

  2. 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.

(a) Lower level
A Front
Rear

YAMAHA YZ450F-2007 - REAR BRAKE PAD INSULATOR INSPECTION - 1

WARNING

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

  • Controller:

  • Niveau du liquide de frein Se reporter à la section “CONTROLE DU NIVEAU DU LIQUIDE DE FREIN”.

  • Controller:

  • Fonctionnement de la pédale de frein
    Sensation de mollesse Purger le circuit de freinage.

Se reporter à la section “PURGE D’AIR DU CIRCUIT DE FREINAGE”.

CONTROLE DE L'ISOLANT DE PLAQUETTE DE FREIN ARRIERE

  1. Inspect:

  2. Sprocket teeth @

Excessive wear Replace.

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

DRIVE CHAIN INSPECTION

  1. Measure:

  2. Drive chain length (15 links) @

Out of specification Replace.

YAMAHA YZ450F-2007 - DRIVE CHAIN INSPECTION - 1

Drive chain length (15 links): : 242.9 mm (9.563 in)

NOTE:

  • While measuring the drive chain length, push down on the drive chain to increase its tension.
  • Measure the length between drive chain roller ① and ⑯ as shown.
  • Perform this measurement at two or three different places.

YAMAHA YZ450F-2007 - DRIVE CHAIN INSPECTION - 2

YAMAHA YZ450F-2007 - DRIVE CHAIN INSPECTION - 3

  1. Remove:

  2. Master link clip

  3. Joint ①
  4. Drive chain ②

  5. Clean:

  6. Drive chain

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

CONTROLE DES PIGNONS

1. Controller:

Dents de pignon @

Usure excessive Remplacer.

N.B.:

  • Drive chain stiffness @

Clean and oil the chain and hold as illustrated.

Stiff Replace drive chain.

5. Install:

  • Drive chain ①
  • Joint ②
  • Master link clip ③ New

CAUTION:

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

@Turning direction

6. Lubricate:

  • Drive chain

YAMAHA YZ450F-2007 - Lubricate: - 1

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

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 YZ450F-2007 - DRIVE CHAIN SLACK ADJUSTMENT - 1

Drive chain slack: 48 58 ~mm (1.9 ~ 2.3 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.

4. Controller:

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 ⑧ 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.
Axle nut: 125 Nm (12.5 m • kg, 90 ft • lb)
·Tighten the locknuts.
Locknut: 19 Nm (1.9 m • kg, 13 ft • lb)

YAMAHA YZ450F-2007 - Controller: - 1

EC36C000

FRONT FORK INSPECTION

1. Inspect:

  • Front fork smooth action

Operate the front brake and stroke the front fork.

Unsmooth action/oil leakage Repair or replace.

CONTROLE DE LA FOURCHE TELESKOPGABEL KONTROLLIEREN

3. Régler:

FRONT FORK OIL SEAL AND DUST SEAL CLEANING

  1. Remove:

  2. Protector

  3. Dust seal ①

NOTE:

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

2. Clean:

  • Dust seal @
  • Oil seal ⑥

NOTE:

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

FRONT FORK INTERNAL PRESSURE RELIEVING

NOTE:

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

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

Air bleed screw

1Nm(0.1m·kg,0.7ft·lb)

EC36H002

FRONT FORK REBOUND DAMPING FORCE ADJUSTMENT

  1. Adjust:

  2. 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.)

NETTOYAGE DE LA BAGUE D'ETANCHENEI ET DU JOINT ANTIPOUSSIÈRE DE FOURCHE

  1. Déposer:

Protection
- Joint antipoussière ①

N.B.:

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

STANDARD POSITION:

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

YAMAHA YZ450F-2007 - NETTOYAGE DE LA BAGUE D'ETANCHENEI ET DU JOINT ANTIPOUSSIÈRE DE FOURCHE - 1

Standard position:

6 clicks out

*8 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.

YAMAHA YZ450F-2007 - WARNING - 1

EC36J001

FRONT FORK COMPRESSION DAMPING FORCE ADJUSTMENT

  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.)

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

STANDARD POSITION:

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

YAMAHA YZ450F-2007 - FRONT FORK COMPRESSION DAMPING FORCE ADJUSTMENT - 1

Standard position:

11 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.

YAMAHA YZ450F-2007 - WARNING - 1

EC36K000

REAR SHOCK ABSORBER INSPECTION

  1. Inspect:

  2. Swingarm smooth action

  3. Abnormal noise/unsmooth action → Grease the pivoting points or repair the pivoting points.
  4. Damage/oil leakage → Replace.

CONTROLE DE L'AMORTISSEUR ARRIREF EDERBEIN KONTROLLIEREN

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

Rear frame

  1. Loosen:
  2. Locknut ①
  3. 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 lengthExtent of adjustment
One I.D. mark 266 mm (10.47 in) *268 mm (10.55 in) Two I.D. marks 272 mm (10.71 in) *274 mm (10.79 in) Three I.D. marks 263.5 mm (10.37 in) *265.5 mm (10.45 in)255.5 ~ 273.5 mm (10.06 ~ 10.77 in) 261.5 ~ 279.5 mm (10.30 ~ 11.00 in) 253.0 ~ 271.0 mm (9.96 ~ 10.67 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 1.5 mm (0.06 in) per turn of the adjuster.
  • The I.D. mark ⑥ is marked at the end of the spring.
  • The standard length and extent of adjustment vary according to the quantity of I.D. marks.

CAUTION:

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

REGLAGE DE LA PRECONTRAINTE DU RESSORT DE L'AMORTISSEUR ARRIERE

  1. Adjust:

  2. Rebound damping force By turning the adjuster ①.

YAMAHA YZ450F-2007 - REGLAGE DE LA PRECONTRAINTE DU RESSORT DE L'AMORTISSEUR ARRIERE - 1

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

YAMAHA YZ450F-2007 - REGLAGE DE LA PRECONTRAINTE DU RESSORT DE L'AMORTISSEUR ARRIERE - 2

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

STANDARD POSITION:

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

YAMAHA YZ450F-2007 - REGLAGE DE LA PRECONTRAINTE DU RESSORT DE L'AMORTISSEUR ARRIERE - 3

Standard position: About 8 clicks out

CAUTION:

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

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

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

YAMAHA YZ450F-2007 - CAUTION: - 1

STANDARD POSITION:

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

YAMAHA YZ450F-2007 - CAUTION: - 2

Standard position: About 8 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 A LA COMPRESSION BASSE DE L'AMORTISSEUR ARRIERE

1. Régler:

  1. Adjust:

  2. High compression damping force By turning the adjuster ①.

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

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

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

YAMAHA YZ450F-2007 - Régler: - 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 YZ450F-2007 - Régler: - 2

Standard position: About 1-1/2 turns out

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 LA COMPRESSION HAUTE DE L'AMORTISSEUR ARRIERE

1. Régler:

  1. Measure:

  2. Tire pressure

Out of specification Adjust.

YAMAHA YZ450F-2007 - Régler: - 1

Standard tire pressure: 100 kPa (1.0 kgf/cm², 15 psi)

NOTE:

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

YAMAHA YZ450F-2007 - NOTE: - 1

EC36S002

SPOKES INSPECTION AND TIGHTENING

  1. Inspect:

  2. Spokes ①

Bend/damage Replace.

Loose spoke Retighten.

  1. Tighten:

Spokes

YAMAHA YZ450F-2007 - SPOKES INSPECTION AND TIGHTENING - 1

3 Nm (0.3 m·kg, 2.2 ft·lb)

NOTE:

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

YAMAHA YZ450F-2007 - NOTE: - 1

EC36T000

WHEEL INSPECTION

  1. Inspect:

  2. Wheel runout

Elevate the wheel and turn it.

Abnormal runout Replace.

CONTROLE DE LA PRESSION DES PNEUS

1. Mesurer:

  • Pression des pneus Hors specifications Régler.

YAMAHA YZ450F-2007 - Mesurer: - 1

Pression des pneus standard: 100kPa (1,0kgf/cm^2, 15psi)

N.B.:

  1. Inspect:

  2. Bearing free play Exist play Replace.

STEERING HEAD INSPECTION AND ADJUSTMENT

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

  3. Steering shaft

  4. Grasp the bottom of the forks and gently rock the fork assembly back and forth.
  5. Free play Adjust steering head.

  6. Check:

  7. Steering smooth action

  8. Turn the handlebar lock to lock.
  9. Unsmooth action Adjust steering ring nut.

  10. Adjust:

  11. 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.
Ring nut wrench: YU-33975/90890-01403

2. Controller:

  • Apply the lithium soap base grease on the thread of the steering shaft.
  • Set the torque wrench to the ring nut wrench so that they form a right angle.

YAMAHA YZ450F-2007 - Controller: - 1

Ring nut wrench: YU-33975/90890-01403

YAMAHA YZ450F-2007 - Controller: - 2

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

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

WARNING

Avoid over-tightening.

YAMAHA YZ450F-2007 - 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 plain washer ⑤ , handle crown ⑥ , plain washer ⑦ , steering shaft nut ⑧ , handlebar ⑨ , handlebar holder (upper) ⑩ and number plate ⑪ .

NOTE:

  • The handlebar holder (upper) should be installed with the punched mark ④ forward.
  • Install the handlebar so that the marks ⑥ are in place on both sides.
  • Install the handlebar so that the projection © of the handlebar holder (upper) is positioned at the mark on the handlebar as shown.
  • Insert the end of fuel breather hose ⑫ into the hole in the steering shaft.

CAUTION:

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

CONTROLE ET REGLAGE DE LA TETE DE FOURCHE LENKKOPFLAGER KONTROLLIEREN UND EINSTellen

Hakenschlüssel: YU-33975/90890-01403

YAMAHA YZ450F-2007 - CONTROLE ET REGLAGE DE LA TETE DE FOURCHE LENKKOPFLAGER KONTROLLIEREN UND EINSTellen - 1

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

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

A Use Yamaha cable lube or equivalent on these areas.
Use SAE 10W-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 YZ450F-2007 - CAUTION: - 1

LUBRIFICATION

  1. Remove:

  2. Spark plug

  3. Inspect:

  4. 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:

  2. Plug gap @

Use a wire gauge or thickness gauge.

Out of specification Regap.

YAMAHA YZ450F-2007 - NOTE: - 1

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

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

YAMAHA YZ450F-2007 - NOTE: - 2

  1. Tighten:

  2. 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

  1. Déposer:

  2. Bougie

  3. Controller:

  4. Electrode ①

Usure/endommagement Remplacer.

IGNITION TIMING CHECK

  1. Remove:

  2. Timing plug ①

  3. Attach:

  4. Timing light

  5. Inductive tachometer To the ignition coil lead (orange lead ①).

YAMAHA YZ450F-2007 - IGNITION TIMING CHECK - 1

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

  1. Adjust:

  2. Engine idling speed Refer to "IDLE SPEED ADJUSTMENT".

YAMAHA YZ450F-2007 - IGNITION TIMING CHECK - 2

  1. Check:

  2. Ignition timing Visually check the stationary pointer (包) is within the firing range (包) on the rotor. Incorrect firing range Check rotor and pickup assembly.

  3. Install:

  4. Timing plug

CONTROLE DE L'AVANCE A L'ALLUMAGE

YAMAHA YZ450F-2007 - CONTROLE DE L'AVANCE A L'ALLUMAGE - 1
Extent of removal:
① Seat removal
③ Side covers removal
(2) Fuel tank removal
④ Number plate removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalSEAT, FUEL TANK AND SIDE COVERS REMOVAL Turn the fuel cock to “OFF”. Disconnect the fuel hose.
①↑ ③↓ ② ④↑1Seat1
2Air scoop (left and right)2
3Bolt (fuel tank)2
4Fuel tank1
5Side cover (left)1Refer to “REMOVAL POINTS”.
6Side cover (right)1
7Number plate1

MOTEUR

SELLE, RESERVOIR DE CARBURANT ET CACHES LATERAUX

YAMAHA YZ450F-2007 - SELLE, RESERVOIR DE CARBURANT ET CACHES LATERAUX - 1

REMOVAL POINTS Side cover

  1. Remove:

  2. Bolt (side cover)

  3. Side cover (left) ①
  4. Side cover (right) ②

NOTE: Draw the side cover downward to remove it because its claws (号) are inserted in the air filter case.

YAMAHA YZ450F-2007 - REMOVAL POINTS Side cover - 1

YAMAHA YZ450F-2007 - REMOVAL POINTS Side cover - 2

Number plate

  1. Remove:

  2. Bolt (number plate)

  3. Number plate ①

NOTE:

  • The projection is inserted into the band of the number plate. Pull the band off the projection before removal.
  • Remove the hot starter cable ② and clutch cable ③ from the cable guide ⑥ on the number plate.
  • The projection © on the under bracket is inserted into the number plate. Remove the number plate by pulling it off the projection.

ASSEMBLY AND INSTALLATION Air scoop

  1. Install:

Air scoop ①
- Bolt (air scoop)

7Nm(0.7m·kg,5.1ft·lb)

NOTE: Put the portion ⑧ of the flap of the air filter case on the inside of the air scoop.

POINTS DE DEPOSE

Cache létaléral

YAMAHA YZ450F-2007 - Cache létaléral - 1
Extent of removal:
① Silencer removal
② Exhaust pipe removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalEXHAUST PIPE AND SILENCER REMOVAL Side cover (right)Refer to “SEAT, FUEL TANK AND SIDE COVERS” section.
②↓1Bolt (clamp)1Only loosening.
2Bolt [silencer (front)]1
3Bolt [silencer (rear)]1
4Collar1
5Silencer1
6Clamp1
7Nut (exhaust pipe)1
8Bolt (exhaust pipe)1
9Exhaust pipe1
10Gasket2

TUBE D'ECHAPPEMENT ET SILENCIEUX AUSPUFFKRÜMMER UND SCHALLDÄMPFER

ENG

YAMAHA YZ450F-2007 - TUBE D'ECHAPPEMENT ET SILENCIEUX AUSPUFFKRÜMMER UND SCHALLDÄMPFER - 1

TUBE D'ECHAPPEMENT ET SILENCIEUX

INSPECTION Exhaust pipe and silencer

  1. Inspect:

  2. Gasket ①

Damage Replace.

Silencer fiber replacement

  1. Remove:

  2. Rivet(front) ①

  3. Inner pipe ②

CAUTION:

Take care not to damage the rivet fitting holes (ø4.9 mm) ⑧ in removal.

NOTE: Pull out the inner pipe while lightly tapping the stay ⑥ on the silencer using a soft hammer.

  1. Replace:

  2. Fiber ①

  3. Install:

  4. Inner pipe ①

  5. Rivet(front) ②

NOTE:

  • Apply heat resistant sealant along the plate edge ⑧ on the inside of the silencer and also along the silencer edge ⑥ as shown.
  • Take care not to allow the fiber out of place when installing the inner pipe.

CONTROLE

ASSEMBLY AND INSTALLATION

Exhaust pipe and silencer

  1. Install:

  2. Gasket New

  3. Exhaust pipe ①
  4. Nut (exhaust pipe) ②

20 Nm (2.0 m·kg, 14 ft·lb)

  • Bolt (exhaust pipe) ③

20 Nm (2.0 m·kg, 14 ft·lb)

NOTE:

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

YAMAHA YZ450F-2007 - NOTE: - 1

YAMAHA YZ450F-2007 - NOTE: - 2

  1. Install:

  2. Clamp ① 14Nm(1.4m·kg,10ft·lb)

  3. Gasket ② New
  4. Silencer ③
  5. Plain washer ④
  6. Bolt (silencer) ⑤

30 Nm (3.0 m·kg, 22 ft·lb)

NOTE:

Install the gasket with its meshed area ④ toward the exhaust pipe side.
- The gasket should be installed according to the dimension shown.

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalRADIATOR REMOVALDrain the coolant.Seat and fuel tankExhaust pipeRefer to “COOLANT REPLACEMENT”section in the CHAPTER 3.Refer to “SEAT, FUEL TANK AND SIDE COVERS” section.Refer to “EXHAUST PIPE ANDSILENCER” section.
11Panel2345678910112811111
2Clamp Radiator (right)Hose 2Hose 3Hose 4Hope 2/O-ringRadiator breather hoseRadiator (left)Hose 1Pipe 1/O-ring8111111
3
4
5
6
7
8
9
10
11

RADIATEUR

YAMAHA YZ450F-2007 - RADIATEUR - 1

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

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

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

YAMAHA YZ450F-2007 - RADIATEUR - 2

YAMAHA YZ450F-2007 - RADIATEUR - 3

YAMAHA YZ450F-2007 - RADIATEUR - 4

EC454000

INSPECTION

EC444100

Radiator

1. Inspect:

  • Radiator core ①

Obstruction Blow out with compressed air through rear of the radiator.

Bent fin Repair/replace.

EC455000

ASSEMBLY AND INSTALLATION

Radiator

1. Install:

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

10 Nm (1.0 m · kg, 7.2 ft · lb)
2 Nm (0.2 m · kg, 1.4 ft · lb)
10 Nm (1.0 m · kg, 7.2 ft · lb)
2 Nm (0.2 m · kg, 1.4 ft · lb)
2 Nm (0.2 m · kg, 1.4 ft · lb)

2. Install:

  • Hose 2 ①
    2Nm(0.2m·kg,1.4ft·lb)
  • Radiator (left) ②
    10 Nm (1.0 m·kg, 7.2 ft·lb)

REMARQUES CONCERNANT LA MANIPULATION

AVERTISSEMENT

  1. Install:

  2. Radiator breather hose ①

  3. Radiator (right) ②

10 Nm (1.0 m·kg, 7.2 ft·lb)

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

  1. Install:

  2. Panel ①

NOTE:

First fit the inner hook portion ⑧ and then the outer one 6 onto the radiator.

  1. Monter:

YAMAHA YZ450F-2007 - AVERTISSEMENT - 1
Extent of removal:
① Carburetor removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCARBURETOR REMOVALFuel tankRear shock absorberRefer to “SEAT, FUEL TANK AND SIDE COVERS” section.Refer to “REAR SHOCK ABSORBER” section in the CHAPTER 5.
1Band1
2TPS coupler1
3Throttle cable cover1
4Throttle cable2
5Clamp (air cleaner joint)1Loosen the screw (air cleaner joint).Loosen the screws (carburetor joint).
6Clamp (carburetor joint)1
7Hot starter plunger1
8Carburetor1
9Carburetor joint1

CARBURATEUR

YAMAHA YZ450F-2007 - CARBURATEUR - 1

YAMAHA YZ450F-2007 - CARBURATEUR - 2
Extent of removal:
① Carburetor disassembly

Extent of removalOrderPart nameQ'tyRemarks
1CARBURETOR DISASSEMBLY
Breather hose4
Valve lever housing cover1
Screw (throttle shaft)1
Throttle valve1
Needle holder1
Jet needle1
Cover1
Spring1
Diaphragm (accelerator pump)1
Float chamber1
Leak jet1
Pilot screw1Refer to “REMOVAL POINTS”.
Float pin1
Float1
Needle valve1

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.

REMOVAL POINTS

Pilot screw

  1. Remove:

  2. 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 YZ450F-2007 - NOTE: - 1

INSPECTION

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.

REMARQUES CONCERNANT LA MANIPULATION

ATTENTION:

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

YAMAHA YZ450F-2007 - ATTENTION: - 1

YAMAHA YZ450F-2007 - ATTENTION: - 2

YAMAHA YZ450F-2007 - ATTENTION: - 3

Needle valve

  1. Inspect:

  2. Needle valve ①

  3. Valve seat ② Grooved wear a Replace. Dust b Clean.
  4. Filter ⑤ Clogged Clean.

EC464300

Throttle valve

  1. Check:

  2. Free movement

  3. Stick Repair or replace.

NOTE:

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

EC464400

Jet needle

  1. Inspect:

  2. Jet needle ① Bends/wear Replace.

  3. Clip groove Free play exists/wear Replace.
  4. Clip position

YAMAHA YZ450F-2007 - Jet needle - 1

Standard clip position: No.4 Groove

  1. Measure:

  2. Float height @

Out of specification Adjust.

YAMAHA YZ450F-2007 - Jet needle - 2

Float height: 8.0 mm (0.31 in)

Measurement and adjustment steps:

  • Hold the carburetor in an upside down position.

NOTE:

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

NOTE:

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

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

YAMAHA YZ450F-2007 - NOTE: - 1

YAMAHA YZ450F-2007 - NOTE: - 2

EC464600

Float

  1. Inspect:

  2. Float ①

Damage Replace.

Hauteur du flotteur

  1. Mesurer:
  1. Inspect:

  2. Diaphragm (accelerator pump) ①
    Spring ②

  3. Cover ③
  4. O-ring ④
  5. Push rod ⑤ Tears (diaphragm)/damage Replace. Dirt Clean.

  6. Inspect:

  7. Throttle shaft ①
    Spring ②

  8. Lever 1 ③
    Spring 1④
  9. Lever 2 (5)
  10. Spring 2 ⑥

Dirt Clean.

ASSEMBLY AND INSTALLATION Carburetor

  1. Install:

Cold starter plunger ①

  1. Install:

  2. Pilot air jet ①

Plongeur de starter

NOTE: Make sure the spring 1 fits on the stopper ④ 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 ⑧ of the spring 2 fits into the recess 6 in the carburetor.

  1. Install:

  2. Plain washer ①
    Circlip ②

  3. Install:

Spring ①

To throttle shaft ②.

NOTE: Install the bigger hook ⑧ of the spring fits on the stopper 6 of the throttle shaft pulley.

  1. Monter:

  2. Ressort 1 ①
    Levier 1 ②

Sur le levier 2 ③

N.B.:

  • Apply the fluorochemical grease on the bearings.
  • Fit the projection ⑧ on the throttle shaft assembly into the slot ⑥ in the TPS (throttle position sensor).
  • Make sure the stopper © of the spring fits into the recess in the carburetor.
  • Turn the throttle shaft assembly left while holding down the lever 1 ⑤ and fit the throttle stop screw tip ⑥ to the stopper ⑧ of the throttle shaft assembly pulley.

9. Install:

  • Push rod ①

NOTE:

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

10. Install:

  • Needle valve ①
  • Float ②
  • Float pin ③

NOTE:

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

  • 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 YZ450F-2007 - Note the following installation points: - 1

Pilot screw (example):

1-1/4 turns out

YAMAHA YZ450F-2007 - 1-1/4 turns out - 1

13.Install:

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

11. Monter:

  • Diaphragm (accelerator pump) ①
    Spring ②
  • O-ring ③
  • Cover ④
  • Hose holder (drain hose) ⑤
  • Screw (cover) ⑥

NOTE:

Install the diaphragm (accelerator pump) with its mark ⑧ facing the spring.

15.Install:

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

16. Install:

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

NOTE:

Install the valve lever rollers ③ into the slits ⑧ of the throttle valve.

17. Install:

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

18. Install:

  • Carburetor breather hose ① Refer to "CABLE ROUTING DIAGRAM" section in the CHAPTER 2.

  • Monter:

  • Diaphragme (pompe de reprise) ①

  • Ressort ②
  • Joint torque ③
    Couvercle ④
  • Support de durit (durit de vidange) ⑤
  • Vis (covercle) ⑥

N.B.:

Accelerator pump timing adjustment

Adjustment steps:

NOTE:

In order for the throttle valve height ⑧ to achieve the specified value, tuck under the throttle valve plate ① the rod ② etc. with the same outer diameter as the specified value.

YAMAHA YZ450F-2007 - NOTE: - 1

Throttle valve height: 1.25 mm (0.049 in)

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

Carburetor installation

1. Install:

  • Carburetor joint ①

10 Nm (1.0 m·kg, 7.2 ft·lb)

2. Install:

  • Carburetor ①

NOTE:

Install the projection @ between the carburetor joint slots.

3. Install:

  • Hot starter plunger ①

2 Nm (0.2 m·kg, 1.4 ft·lb)

  • Bolt (carburetor joint) ①
    3Nm(0.3m·kg,2.2ft·lb)
  • Bolt (air cleaner joint) ②
    3Nm(0.3m·kg,2.2ft·lb)

5. Install:

  • Throttle cable (pull) ①
    4Nm(0.4m·kg,2.9ft·lb)
  • Throttle cable (return) ②
    11Nm(1.1m·kg,8.0ft·lb)

6. Adjust:

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

7. Install:

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

4Nm(0.4m·kg,2.9ft·lb)

8. Install:

  • TPS (throttle position sensor) coupler ①
  • Clamp ② Refer to "CABLE ROUTING DIAGRAM" section in the CHAPTER 2.

  • Serrer:

  • Boulon (raccord du carburateur) ①
    3Nm(0,3m·kg,2,2ft·lb)
  • Boulon (raccord du filtré à air) ②
    3Nm (0,3m· kg,2,2ft· lb)

  • Festziehen:

  • Schraube (Vergasereinlass-Anschluss) ①
    3Nm(0,3m·kg,2,2ft·lb)

  • Schraube (Vergasereinlass-Anschluss) ②
    3Nm(0,3m·kg,2,2ft·lb)

  • Monter:

Extent of removal:
① Cylinder head cover removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCYLINDER HEAD COVER REMOVALRefer to “SEAT, FUEL TANK AND SIDE COVERS” section. Refer to “CARBURETOR” section. Refer to “ENGINE REMOVAL” section.
Seat and fuel tank
Hot starter plunger
Engine upper bracket (right)
Engine upper bracket (left)
11Spark plug1
2Cylinder head breather hose1
3Bolt (cylinder head cover)2
4Cylinder head cover1
5Gasket1
6Timing chain guide (top)1

ARBRES A CAMES

COUVRE-CULASSE

YAMAHA YZ450F-2007 - COUVRE-CULASSE - 1
Extent of removal:
① Camshaft removal

Extent of removalOrderPart nameQ'tyRemarks
1CAMSHAFTS REMOVALRefer to “REMOVAL POINTS”.
1Timing plug1
2Straight plug1
3Tensioner cap bolt1
4Timing chain tensioner1
5Gasket1
6Bolt (camshaft cap)10
7Camshaft cap2
8Clip2
9Exhaust camshaft1
10Intake camshaft1

ARBRES A CAMES

REMOVAL POINTS Camshaft

  1. Remove:

  2. Timing plug ①

  3. Straight plug ②

  4. Align:

"l" mark

With stationary pointer.

Checking steps:

  • Turn the crankshaft counterclockwise with a wrench.
  • Align the "l" mark ⑧ on the rotor with the stationary pointer ⑥ on the crankcase cover. When the "l" 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 ⑥ on the exhaust camshaft and the punch mark ① on the intake camshaft must align with the cylinder head surface, as shown in the illustration.
  • If there is no clearance, rotate the crankshaft counterclockwise one turn.

  • Loosen:

  • Tensioner cap bolt ①
  • Remove:
  • Timing chain tensioner ②

  • Remove:

  • Bolt (camshaft cap) ①

  • Camshaft caps ②

NOTE: Remove the bolts (camshaft cap) in a crisscross pattern, working from the outside in.

CAUTION:

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

POINTS DE DEPOSE

Arbre à cames

  1. Remove:

  2. Clips

  3. Exhaust camshaft ①
  4. Intake camshaft ②

NOTE:

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

INSPECTION

Camshaft

  1. Inspect:

  2. Cam lobes

Pitting/scratches/blue discoloration Replace.

  1. Measure:

  2. Cam lobes length ⑧ and ⑥

Out of specification Replace.

YAMAHA YZ450F-2007 - Camshaft - 1

Cam lobes length: Intake:

@ 31.200 ~ 31.300 mm

(1.2283 ~ 1.2323 in)

: 31.100 mm

(1.2244 in)

⑥ 22.550 ~ 22.650 mm

(0.8878 ~ 0.8917 in)

: 22.450 mm

(0.8839 in)

Exhaust:

@ 30.950 ~ 31.050 mm

(1.2185 ~ 1.2224 in)

: 30.850 mm

(1.2146 in)

⑥ 22.494\~22.594mm

(0.8856 ~ 0.8895 in)

: 22.394 mm

(0.8817 in)

YAMAHA YZ450F-2007 - Camshaft - 2

  1. Measure:

  2. Runout (camshaft)

Out of specification Replace.

YAMAHA YZ450F-2007 - Camshaft - 3

Runout (camshaft):

Less than 0.03 mm (0.0012 in)

  • Camshaft-to-cap clearance

Out of specification Measure camshaft journal diameter.

YAMAHA YZ450F-2007 - Camshaft - 4

YAMAHA YZ450F-2007 - Camshaft - 5

YAMAHA YZ450F-2007 - Camshaft - 6

YAMAHA YZ450F-2007 - Camshaft - 7

YAMAHA YZ450F-2007 - Camshaft - 8

Camshaft-to-cap clearance:

0.028 ~ 0.062 mm

(0.0011 ~ 0.0024 in)

: 0.08 mm (0.003 in)

Measurement steps:

  • 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 YZ450F-2007 - Measurement steps: - 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:

  • Camshaft journal diameter @

Out of specification Replace the camshaft.

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

YAMAHA YZ450F-2007 - Measure: - 1

Camshaft journal diameter:

21.959 ~ 21.972 mm

(0.8645 ~ 0.8650 in)

Camshaft sprocket

1. Inspect:

  • Camshaft sprocket ①

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

4. Mesurer:

Decompression system

  1. Check:

  2. Decompression system

Checking steps:

  • Check that the decompressor cam ① moves smoothly.
  • Check that the decompressor lever pin ② projects from the camshaft.

Timing chain tensioner

  1. Check:

  2. While pressing the tensioner rod lightly with fingers, use a thin screwdriver ① and wind the tensioner rod up fully clockwise.

  3. When releasing the screwdriver by pressing lightly with fingers, make sure that the tensioner rod will come out smoothly.
  4. If not, replace the tensioner assembly.

ASSEMBLY AND INSTALLATION

  1. Install:

  2. Exhaust camshaft ①

  3. Intake camshaft ②

Installation steps:

  • Turn the crankshaft counterclockwise until the "l" mark ⑧ on the rotor is aligned with the stationary pointer ⑥ on the crankcase cover.

NOTE:

  • Apply the molybdenum disulfide oil on the camshafts.
  • Apply the engine oil on the decompression system.

Décompresseur

  • 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 ⑥ and the intake cam sprocket punch mark ⑥ 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 clips and camshaft caps ④.

YAMAHA YZ450F-2007 - CAUTION: - 1

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

YAMAHA YZ450F-2007 - CAUTION: - 2

NOTE:

  • Apply the molybdenum disulfide oil on the thread of the bolts (camshaft cap) ⑤.
  • Tighten the bolts to the specified torque in two or three steps in the proper tightening sequence as shown.

CAUTION:

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

YAMAHA YZ450F-2007 - CAUTION: - 1

  1. Install:

  2. Timing chain tensioner

Installation steps:

  • With the rod fully wound and the chain tensioner UP mark ⑧ facing upward, install the gasket ① , the chain tensioner ② and the gasket ③ , and tighten the bolt ④ to the specified torque.

YAMAHA YZ450F-2007 - Installation steps: - 1

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 ⑤ and the cap bolt ⑥ to the specified torque.

YAMAHA YZ450F-2007 - Installation steps: - 2

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

  1. Turn:

Crankshaft

Counterclockwise several turns

  1. Check:

  2. Rotor "I" mark

Align with the crankcase stationary pointer.

  • Camshaft match marks

Align with the cylinder head surface.

Out of alignment Adjust.

Extent of removal:
① Cylinder head removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCYLINDER HEAD REMOVAL Seat and fuel tank Exhaust pipe and silencer Radiator Carburetor CamshaftRefer to “SEAT, FUEL TANK AND SIDE COVERS” section.Refer to “EXHAUST PIPE AND SILENCER” section.Refer to “RADIATOR” section.Refer to “CARBURETOR” section.Refer to “CAMSHAFTS” section.
112*3456BoltBoltCylinder headGasketDowel pinTiming chain guide (front)24111211

NOTE:

Tighten the cylinder head bolts to 30Nm ( 3.0m · kg, 22ft · lb ) in the proper tightening sequence, remove and retighten the cylinder head bolts to 20Nm ( 2.0m · kg, 14ft · lb ) in the proper tightening sequence, and then tighten the cylinder head bolts further to reach the specified angle 180^ in the proper tightening sequence.

CULASSE

CULASSE

  1. Eliminate:

  2. 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

  • Inspect:

  • Cylinder head

Scratches/damage Replace.

YAMAHA YZ450F-2007 - NOTE: - 1

  1. Measure:

  2. Cylinder head warpage

Out of specification Resurface.

YAMAHA YZ450F-2007 - NOTE: - 2

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

Warpage measurement and re-surface-ment steps:

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

NOTE:

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

CONTROLE

Culasse

ASSEMBLY AND INSTALLATION

  1. Install:

  2. Timing chain guide (front) ①
    Dowel pin ②

  3. Cylinder head gasket ③ New
  4. Cylinder head ④

NOTE: While pulling up the timing chain, install the timing chain guide (front) and cylinder head.

  1. Install:

  2. Plain washer ①

  3. Bolt ②

Installation steps:

CAUTION:

Tighten the cylinder head using the rotation angle procedure to obtain uniform tightening torque.

  • Wash the threads and contact surfaces of the bolts, the contact surfaces of the plain washers, the contact surface of the cylinder head, and the threads of the crankcase.
  • Apply the molybdenum disulfide grease on the threads and contact surfaces of the bolts and on both contact surfaces of the plain washers.
  • Install the plain washers and bolts.
  • Tighten the bolts to the specified torque in two or three steps in the proper tightening sequence as shown.

YAMAHA YZ450F-2007 - CAUTION: - 1

Bolts (cylinder head):

1st:

30 Nm (3.0 m • kg, 22 ft • lb)

ASSEMBLAGE ET MONTAGE

1. Monter:

  • Remove the bolts.
  • Again apply the molybdenum disulfide grease on the threads and contact surfaces of the bolts and on both contact surfaces of the plain washers.
  • Retighten the bolts.

NOTE:

Tighten the bolts to the specified torque in two or three steps in the proper tightening sequence as shown.

YAMAHA YZ450F-2007 - NOTE: - 1

Bolts (cylinder head):

2nd:

20 Nm (2.0 m • kg, 14 ft • lb)

  • Put a mark on the corner ① of the bolt (cylinder head) and the cylinder head ② as shown.

NOTE:

Tighten the bolts 90^ in each of the two steps to reach the specified angle of 180^ in the proper tightening sequence as shown.

YAMAHA YZ450F-2007 - NOTE: - 1

Bolts (cylinder head):

Final:

Specified angle 180^

3. Install:

  • Bolt (cylinder head) ①

10 Nm (1.0 m·kg, 7.2 ft·lb)

Extent of removal:
① Valve removal

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

SOUPAPES ET RESSORTS DE SOUPAPES VENTILE UND VENTILFEDERN

ENG

YAMAHA YZ450F-2007 - SOUPAPES ET RESSORTS DE SOUPAPES VENTILE UND VENTILFEDERN - 1

SOUPAPES ET RESSORTS DE SOUPAPES

SOUPAPES ET RESSORTS DE SOUPAPES

Valve lifter and valve cotter

  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 between the valve spring retainer and the cylinder head to remove the valve cotters.

YAMAHA YZ450F-2007 - Checking steps: - 1

Valve spring compressor: YM-4019/90890-04019

POINTS DE DEPOSE

  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 YZ450F-2007 - 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:

0.020 ~ 0.047 mm

(0.0008 ~ 0.0019 in)

: 0.10 mm (0.004 in)

  1. Replace:

  2. 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.

CONTROLE

Soupape

  1. Mesurer:

  2. Jeu queue-guide

Intake: 4.5 mm (0.18 in)

YM-4116/90890-04116

Exhaust: 5.0 mm (0.20 in)

YM-4097/90890-04097

Valve guide installer:

Intake:

YM-4117/90890-04117

Exhaust:

YM-4098/90890-04098

Valve guide reamer:

Intake: 4.5 mm (0.18 in)

YM-4118/90890-04118

Exhaust: 5.0 mm (0.20 in)

YM-4099/90890-04099

NOTE:

After replacing the valve guide reface the valve seat.

  1. Inspect:

  2. Valve face

Pitting/wear Grind the face.

  • Valve stem end

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

YAMAHA YZ450F-2007 - NOTE: - 1

  1. Measure:

  2. Margin thickness @

Out of specification Replace.

YAMAHA YZ450F-2007 - NOTE: - 2

Margin thickness:

Intake:

1.0 mm (0.039 in)

: 0.85 mm (0.033 in)

Exhaust:

1.0 mm (0.039 in)

: 0.85 mm (0.033 in)

YAMAHA YZ450F-2007 - NOTE: - 3

Echappement: 5,0 mm (0,20 in)

YM-4097/90890-04097

Echappement: 5,0 mm (0,20 in)

YM-4099/90890-04099

N.B.:

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

6. Eliminate:

  • Carbon deposits

(from the valve face and valve seat)

7. Inspect:

  • Valve seats

Pitting/wear Reface the valve seat.

YAMAHA YZ450F-2007 - Inspect: - 1

8. Measure:

  • Valve seat width @

Out of specification Reface the valve seat.

YAMAHA YZ450F-2007 - Measure: - 1

Valve seat width:

Intake:

$$ 0. 9 \sim 1. 1 \mathrm {m m} (0. 0 3 5 4 \sim 0. 0 4 3 3 \mathrm {i n}) $$

$$ < \text {L i m i t} >: 1. 6 \mathrm {m m} (0. 0 6 3 0 \mathrm {i n}) $$

Exhaust:

$$ 0. 9 \sim 1. 1 \mathrm {m m} (0. 0 3 5 4 \sim 0. 0 4 3 3 \mathrm {i n}) $$

$$ < \text {L i m i t} >: 1. 6 \mathrm {m m} (0. 0 6 3 0 \mathrm {i n}) $$

YAMAHA YZ450F-2007 - Valve seat width: - 1

Measurement steps:

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

SOUPAPES ET RESSORTS DE SOUPAPES VENTILE UND VENTILFEDERN

ENG

YAMAHA YZ450F-2007 - SOUPAPES ET RESSORTS DE SOUPAPES VENTILE UND VENTILFEDERN - 1

  1. Mesurer:

  2. Faux-rond (queue de soupape)
    Hors specifications Remplacer.

YAMAHA YZ450F-2007 - SOUPAPES ET RESSORTS DE SOUPAPES VENTILE UND VENTILFEDERN - 2

Limin de faux-rond: 0,01 mm (0,0004 in)

N.B.:

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

YAMAHA YZ450F-2007 - N.B.: - 1

YAMAHA YZ450F-2007 - N.B.: - 2

YAMAHA YZ450F-2007 - N.B.: - 3

Lapping steps:

  • Apply a coarse lapping compound to the valve face.

CAUTION:

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

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

NOTE:

For best lapping results, lightly tap the valve seat while rotating the valve back and forth between your hands.
- Apply a fine lapping compound to the valve face and repeat the above steps.

NOTE:

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

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

SOUPAPES ET RESSORTS DE SOUPAPES VENTILE UND VENTILFEDERN

9. Roder:

  1. Measure:

  2. Valve spring free length @

Out of specification Replace.

YAMAHA YZ450F-2007 - Roder: - 1

Free length (valve spring):

Intake:

37.03 mm (1.46 in)

: 36.03 mm (1.42 in)

Exhaust:

37.68 mm (1.48 in)

: 36.68 mm (1.44 in)

  1. Measure:

  2. Compressed spring force @

Out of specification Replace.

6 Installed length

YAMAHA YZ450F-2007 - Roder: - 2

Compressed spring force:

Intake:

111.3 ~ 127.9 N at 27.87 mm

(11.3 ~ 13.0 kg at 27.87 mm,

24.91 ~ 28.66 lb at 1.10 in)

Exhaust:

127.4 ~ 146.4 N at 27.38 mm

(13.0 ~ 14.9 kg at 27.38 mm,

28.66 ~ 32.85 lb at 1.08 in)

YAMAHA YZ450F-2007 - Roder: - 3

YAMAHA YZ450F-2007 - Roder: - 4

  1. Measure:

Spring tilt @

Out of specification Replace.

YAMAHA YZ450F-2007 - Roder: - 5

Spring tilt limit:

Intake:

2.5°/1.61 mm (0.063 in)

Exhaust:

2.5^ / 1.65 ~mm (0.065 in)

Valve lifter

  1. Inspect:

  2. Valve lifter

Scratches/damage Replace both lifters and cylinder head.

Ressort de soupape

1. Mesurer:

  • Force du ressort comprime @

Hors specifications Remplacer.

Force du ressort comprime:

Admission:

ASSEMBLY AND INSTALLATION

  1. Apply:

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

  3. Install:

  4. Valves ①

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

NOTE:

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

Intake (middle) @: blue

Intake (right/left) ⑥: gray

Exhaust: not paint

Install the valve springs with the larger pitch facing upward.

Smaller pitch

YAMAHA YZ450F-2007 - NOTE: - 1

YAMAHA YZ450F-2007 - NOTE: - 2

  1. Install:

  2. Valve cotters

NOTE:

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

YAMAHA YZ450F-2007 - NOTE: - 1

Valve spring compressor: YM-4019/90890-04019

  1. To secure the valve cotters onto the valve stem, lightly tap the valve tip with a piece of wood.

CAUTION:

Hitting the valve tip with excessive force could damage the valve.

ASSEMBLAGE ET MONTAGE

1. Appliquer:

  1. Install:

  2. Adjusting pad ①

  3. Valve lifter ②

NOTE:

  • Apply the engine oil on the valve lifters.
  • Apply the molybdenum disulfide oil on the valve stem end.
  • 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 SOUPAPES VENTILE UND VENTILFEDERN

YAMAHA YZ450F-2007 - SOUPAPES ET RESSORTS DE SOUPAPES VENTILE UND VENTILFEDERN - 1
Extent of removal:
① Cylinder removal
② Piston removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCYLINDER AND PISTON REMOVAL Cylinder headRefer to “CYLINDER HEAD” section.
11Bolt (cylinder)1
22Cylinder1
33Gasket1
44Dowel pin2
55Piston pin clip2
66Piston pin1Use special tool. Refer to “REMOVAL POINTS”.
77Piston1
88Piston ring set1

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 YZ450F-2007 - CYLINDRE ET PISTON - 1

Piston pin puller: YU-1304/90890-01304

CAUTION:

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

Piston ring

  1. Remove:

  2. 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:

  2. Cylinder and piston walls

Vertical scratches Replace cylinder and piston.

  1. Measure:
  2. Piston-to-cylinder clearance

YAMAHA YZ450F-2007 - 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

Cylinder bore “C”95.00 ~ 95.01 mm (3.7402 ~ 3.7406 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. @ 8 mm (0.315 in) from the piston bottom edge
Piston size “P”
Standard94.945 ~ 94.960 mm (3.738 ~ 3.739 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>: 0.1 mm (0.004 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)0.12 mm (0.005 in)
2nd ring0.020 ~ 0.055 mm (0.0008 ~ 0.0022 in)0.12 mm (0.005 in)

2. Position:

  • Piston ring

(in cylinder)

NOTE:

Insert a ring into the cylinder and push it approximately 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.

@ 10 mm (0.39 in)

3. Measure:

  • Ring end gap

Out of specification Replace.

NOTE:

You cannot measure the end gap on the expander spacer of the oil control ring. If the oil control ring rails show excessive gap, replace all three rings.

End gap:
Standard<Limit>
Top ring0.20 ~ 0.30 mm (0.008 ~ 0.012 in)0.55 mm (0.022 in)
2nd ring0.35 ~ 0.50 mm (0.014 ~ 0.020 in)0.85 mm (0.033 in)
Oil ring0.20 ~ 0.50 mm (0.01 ~ 0.02 in)

Segment de piston

1. Mesurer:

Blue discoloration/grooves Replace, then inspect the lubrication system.

  1. Measure:
  2. Piston pin-to-piston clearance

Measurement steps:

Measure the outside diameter (piston pin) ⑧ If out of specification, replace the piston pin.

YAMAHA YZ450F-2007 - Measurement steps: - 1

Outside diameter (piston pin):

17.991 ~ 18.000 mm

(0.7083 ~ 0.7087 in)

Measure the inside diameter (piston) ⑥.

YAMAHA YZ450F-2007 - 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 YZ450F-2007 - 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 YZ450F-2007 - Measurement steps: - 4

ASSEMBLY AND INSTALLATION

Piston

  1. Install:

  2. 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. Controller:

  • 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)

3. 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 () on the piston points to the exhaust side of the engine.
  • Before installing the piston pin clip, cover the crankcase with a clean rag to prevent the piston pin clip from falling into the crankcase.
  • Install the piston pin clips with their ends facing downward.

4. Lubricate:

Piston
- Piston rings
- Cylinder

NOTE:

Apply a liberal coating of engine oil.

Cylinder

  1. Install:

  2. Dowel pins

  3. Gasket ① New
  4. 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 guide ④ during installation.

2. Install:

  • Bolt (cylinder)

10 Nm (1.0 m · kg, 7.2 ft · lb)

  1. Position:

YAMAHA YZ450F-2007 - Install: - 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 removalOrderPart nameQ'tyRemarks
Preparation for removalCLUTCH REMOVALDrain the engine oil.Brake pedalClutch cableRefer to "ENGINE OIL REPLACEMENT"section in the CHAPTER 3.Refer to "ENGINE REMOVAL" section.Disconnect at engine side.
1241234Clutch coverGasketDowel pinClutch springPressure platePush rod 1CirclipPlain washerBearingBallPush rod 211261111

EMBRAYAGE

EMBRAYAGE

YAMAHA YZ450F-2007 - EMBRAYAGE - 1

  1. Remove:

  2. Nut ①

  3. Lock washer ②
  4. Clutch boss ③

NOTE:

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

YAMAHA YZ450F-2007 - NOTE: - 1

Clutch holding tool: YM-91042/90890-04086

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:

  2. Circumferential play Free play exists Replace.
    Gear teeth ④ Wear/damage Replace.

EC484400

Clutch spring

  1. Measure:

  2. Clutch spring free length ⑧ Out of specification Replace springs as a set.

YAMAHA YZ450F-2007 - Clutch spring - 1

Clutch spring free length:

Standard<Limit>
50.0 mm (1.97 in)49.0 mm (1.93 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 YZ450F-2007 - Noix d'embrayage - 1

Friction plate thickness:

2.92 ~ 3.08 mm

(0.115 ~ 0.121 in)

: 2.8 mm (0.110 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 YZ450F-2007 - Measure: - 1

Warp limit:

0.1 mm (0.004 in)

YAMAHA YZ450F-2007 - Measure: - 2

YAMAHA YZ450F-2007 - Measure: - 3

Push lever

1. Inspect:

  • Push lever ①

Wear/damage Replace.

EC484810

Push rod

1. Inspect:

  • Push rod 1 ①
  • Bearing ②
  • Plain washer ③
  • Push rod 2 ④
    Ball ⑤

Wear/damage/bend Replace.

Disque garni

1. Mesurer:

ASSEMBLY AND INSTALLATION

Push lever

  1. Install:

  2. Push lever ①

NOTE:

  • Apply the lithium soap base grease on the oil seal lip.
  • Apply the engine oil on the push lever.

Clutch

  1. Install:

  2. Primary driven gear ①

  3. Thrust washer ②
  4. Clutch boss ③

NOTE:

Apply the engine oil on the primary driven gear inner circumference.

  1. Install:

  2. Lock washer ①

YAMAHA YZ450F-2007 - NOTE: - 1

  • Nut (clutch boss) ②

YAMAHA YZ450F-2007 - NOTE: - 2

75Nm (7.5 m·kg, 54 ft·lb)

NOTE:

  • Install the lock washer with its concaves fitted over the convexes of the clutch boss.
  • Use the clutch holding tool ③ to hold the clutch boss.

YAMAHA YZ450F-2007 - NOTE: - 1

Clutch holding tool: YM-91042/90890-04086

For USA and CDN
Except for USA and CDN

  1. Bend the lock washer ① tab.

ASSEMBLAGE ET MONTAGE

Tige de poussée

  1. Monter:

Tige de poussée ①

N.B.:

  1. Install:

  2. Friction plate ①

  3. Clutch plate ②

NOTE:

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

YAMAHA YZ450F-2007 - NOTE: - 1

YAMAHA YZ450F-2007 - NOTE: - 2

YAMAHA YZ450F-2007 - NOTE: - 3

  1. Install:

  2. Bearing ①

  3. Plain washer ②
  4. Circlip ③ New

To push rod 1 ④.

NOTE:

Apply the engine oil on the bearing and plain washer.

  1. Install:

  2. Push rod 2 ①
    Ball ②

  3. Push rod 1 ③

NOTE:

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

  1. Install:

  2. Pressure plate ①

  3. Monter:

  4. Disque garni ①

  5. Plateau de pression ②

N.B.:

NOTE: Tighten the bolts in stage, using a crisscross pattern.

  1. Install:

  2. Gasket (clutch cover) ①
    Dowel pin ②

New

  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.

  1. Monter:

  2. Ressort d'embrayage

  3. Boulon (ressort d'embrayage)

10 Nm (1,0 m · kg, 7,2 ft · lb)

N.B.:

② Water pump removal
YAMAHA YZ450F-2007 - N.B.: - 1
① Oil filter removal

Extent of removal:

③ Crankcase cover (right) removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalOIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) REMOVALRefer to “ENGINE REMOVAL” section. Refer to “ENGINE OIL REPLACEMENT” section in the CHAPTER 3. Refer to “COOLANT REPLACEMENT” section in the CHAPTER 3. Refer to “EXHAUST PIPE AND SILENCER” section. Refer to “ENGINE REMOVAL” section. Refer to “CLUTCH” section.
Engine guard (right)
Drain the engine oil.
Drain the coolant.
Exhaust pipe
Brake pedal
Clutch cover
11Oil filter cover1
2Oil filter1
3Coolant pipe 21
4Water pump housing1
5Pin2

FILTRE A HUIL, POMPE A EAU ET COUVERCLE DE STARTER (DROIT)

YAMAHA YZ450F-2007 - FILTRE A HUIL, POMPE A EAU ET COUVERCLE DE STARTER (DROIT) - 1

FILTRE A HUIL, POMPE A EAU ET COUVERCLE DE STARTER (DROIT)

Hold the impeller shaft on its width across the flats 已 with spanners, etc. and remove the impeller.

EC4G3210

Oil seal

NOTE:

It is not necessary to disassemble the water pump, unless there is an abnormality such as excessive change in coolant level, discoloration of coolant, or milky transmission oil.

  1. Remove:

  2. Bearing ①

  3. Oil seal ②

INSPECTION

EC444200

Impeller shaft

  1. Inspect:

  2. Impeller shaft ①

Bend/wear/damage Replace.

Furdeposits Clean.

POINTS DE DEPOSE

Axe de pompe

  1. Inspect:

  2. Bearing

  3. Rotate inner race with a finger.
  4. Rough spot/seizure Replace.

Oil seal

  1. Inspect:

  2. Oil seal Wear/damage Replace.

YAMAHA YZ450F-2007 - Oil seal - 1

YAMAHA YZ450F-2007 - Oil seal - 2

ASSEMBLY AND INSTALLATION

EC4G5110

Oil seal

  1. Install:

  2. 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:

  2. Bearing ①

NOTE:

Install the bearing by pressing its outer race parallel.

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, bearing and impeller shaft. And install the shaft while turning it.
  • Hold the impeller shaft on its width across the flats ⑧ with spanners, etc. and install the impeller.

Crankcase cover (right)

  1. Install:

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

NOTE:

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

  1. Install:

  2. Crankcase cover (right) ①

  3. Bolt ②
  4. Bolt

12 Nm (1.2 m·kg, 8.7 ft·lb)
10 Nm (1.0 m·kg, 7.2 ft·lb)

NOTE:

  • Apply the engine oil on the impeller shaft end.
  • 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 pompe

  1. Monter:

  2. Axe de pompe ①
    Rondelle pleine ②

  3. Rotor ③

14 Nm (1,4 m·kg, 10 ft·lb)

N.B.:

  1. Install:

  2. Kick starter ①

  3. Plain washer
  4. Bolt (kick starter)

YAMAHA YZ450F-2007 - N.B.: - 1

33 Nm (3.3 m·kg, 24 ft·lb)

NOTE: Install so that there is a clearance ④ of 8mm (0.31 in) or more between the kick starter and frame and that the kick starter does not contact the crankcase cover when it is pulled.

YAMAHA YZ450F-2007 - N.B.: - 2

YAMAHA YZ450F-2007 - N.B.: - 3

YAMAHA YZ450F-2007 - N.B.: - 4

  1. Install:

  2. Oil tank breather hose ①

  3. Clamp ②

2Nm (0.2m·kg, 1.4 ft·lb)

Water pump housing

  1. Install:

Dowel pin ①
- O-ring ② New

NOTE:

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

  1. Install:

Water pump housing ①
- Bolt (water pump housing) ②

10 Nm (1.0 m·kg, 7.2 ft·lb)

  • Plain washer ③

YAMAHA YZ450F-2007 - Water pump housing - 1

Coolant drain bolt ④

10Nm(1.0m·kg,7.2ft·lb)

Lanceur au pied

  1. Monter:
  1. Install:

  2. O-ring New
    Coolant pipe ①

  3. Bolt (coolant pipe) ②

10 Nm (1.0 m·kg, 7.2 ft·lb)

NOTE:

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

Oil filter

  1. Install:

  2. Oil filter ①

  3. O-ring ②
  4. Oil filter cover ③
  5. Bolt (oil filter cover)

10 Nm (1.0 m·kg, 7.2 ft·lb)

NOTE:

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

FILTRE A HUIL, POMPE A EAU ET COUVERCLE DE STARTER (DROIT) ÖLFILTER, WASSERPUMPE UND KURBELGEHÄUSEDECKEL RECHTS

3. Monter:

Extent of removal:
① Balancer drive gear
② Balancer

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalBALANCER REMOVAL Clutch housing Crankcase cover (right) StatorRefer to “CLUTCH” section.Refer to “OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)” section.Refer to “CDI MAGNETO” section.
②↑1Nut (balancer)1Refer to “REMOVAL POINTS”.
2Nut (primary drive gear)1
3Nut (balancer driven gear)1
4Lock washer1
5Balancer1
6Straight key1
7Conical washer1
8Primary drive gear1
9Balancer drive gear1
10Lock washer1
11Balancer driven gear1

BALANCIER

BALANCIER

YAMAHA YZ450F-2007 - BALANCIER - 1

Balancer, balancer drive gear and balancer driven gear

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

  3. Nut (balancer) ①

  4. Nut (primary drive gear) ②
  5. Nut (balancer driven gear) ③

NOTE:

Place an aluminum plate ⑧ between the teeth of the balancer drive gear ④ and balancer driven gear ⑤ .

INSPECTION

Primary drive gear, balancer drive gear and balancer driven gear

  1. Inspect:

  2. Primary drive gear ①
    Balancer drive gear ②

  3. Balancer driven 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:

  2. Balancer driven gear ①

NOTE:

Install the balancer driven gear and balancer shaft with their lower splines ⑧ aligning with each other.

  1. Install:

  2. Balancer drive gear ①

NOTE:

  • Align the punched mark ④ on the balancer drive gear with the punched mark 6 on the balancer driven gear.
  • Install the balancer driven gear and crankshaft with the lower splines © aligning with each other.

  • Install:

  • Lock washer ①

  • Nut (balancer driven gear) ②

50 Nm (5.0 m · kg, 36 ft · lb)

Primary drive gear ③
- Conical washer ④
- Nut (primary drive gear) ⑤

110 Nm (11.0 m·kg, 80 ft·lb)

  • Straight key ⑥
  • Balancer ⑦
  • Lock washer ⑧
  • Nut (balancer) ⑨
  • Apply engine oil to the contact surface and threaded portion of the nut (primary drive gear).
  • Place an aluminum plate ⑧ between the teeth of the balancer drive gear ⑩ and balancer driven gear 11 .
  • Install the primary drive gear with its weight reduction holes ⑥ facing the engine.
    Install the conical washer with its convex surface outward.

  • Bend the lock washer tab.

ASSEMBLAGE ET MONTAGE

YAMAHA YZ450F-2007 - ASSEMBLAGE ET MONTAGE - 1
Extent of removal:
① Oil pump removal
② Oil pump disassembly

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalOIL PUMP REMOVAL AND DIS-ASSEMBLY Clutch housing Crankcase cover (right)Refer to “CLUTCH” section.Refer to “OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)” section.
121Circlip1
2Plate washer1
3Oil pump drive gear1
4Oil pump assembly1
5Dowel pin2
6Outer rotor 21
7Circlip1
8Inner rotor 21
9Pin1
10Oil pump cover1
11Outer rotor 11
12Inner rotor 11

POMPE A HUIL

POMPE A HUIL

  1. Inspect:

  2. Oil pump drive gear

  3. Oil pump driven gear
  4. Rotor housing
  5. Oil pump cover

Cracks/wear/damage Replace.

YAMAHA YZ450F-2007 - POMPE A HUIL - 1

YAMAHA YZ450F-2007 - POMPE A HUIL - 2

YAMAHA YZ450F-2007 - POMPE A HUIL - 3

  1. Measure:

  2. Tip clearance @

Between the inner rotor ① and the outer rotor ②.

  • Tip clearance ⑥

Between the outer rotor ② and the rotor housing ③

Out of specification Replace the oil pump.

YAMAHA YZ450F-2007 - POMPE A HUIL - 4

Tip clearance a:

0.12 mm or less

(0.0047 in or less)

: 0.20 mm (0.008 in)

Tip clearance ⑥

0.09 ~ 0.17 mm (0.0035 ~ 0.0067 in)

: 0.24 mm (0.009 in)

Side clearance

0.03 ~ 0.10 mm (0.0012 ~ 0.0039 in)

: 0.17 mm (0.007 in)

  1. Check:

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

ASSEMBLY AND INSTALLATION

Oil pump

  1. Install:

  2. Oil pump drive shaft ①

  3. Washer ②
    Pin ③
  4. Inner rotor 1 ④

NOTE:

  • Apply the engine oil on the oil pump drive shaft and inner rotor 1.
  • Fit the pin into the groove in the inner rotor 1.

CONTROLE

Pompe à huiè

1. Controller:

NOTE: Apply the engine oil on the outer rotor 1.

  1. Install:

  2. Oil pump cover ①

  3. Screw (oil pump cover) ②

2Nm(0.2m·kg,1.4ft·lb)

Pin ③
- Inner rotor 2 ④
- Circlip ⑤ New

NOTE:

  • Apply the engine oil on the oil pump drive shaft end and inner rotor 2.
  • Fit the pin into the groove in the inner rotor 2.

YAMAHA YZ450F-2007 - Controller: - 1

YAMAHA YZ450F-2007 - Controller: - 2

  1. Install:

  2. Outer rotor 2 ①
    Dowel pin ②

  3. Oil pump assembly ③
  4. Bolt (oil pump assembly) ④

10 Nm (1.0 m·kg, 7.2 ft·lb)

NOTE:

Apply the engine oil on the outer rotor 2.

  1. Install:

  2. Oil pump drive gear ①

  3. Plate washer ②
  4. Circlip ③ New

NOTE:

Apply the engine oil on the oil pump drive gear inner circumference.

  1. Monter:

  2. Rotor externe 1 (1)

N.B.:

KICK AXLE AND SHIFT SHAFT

KICK AXLE AND SHIFT SHAFT

YAMAHA YZ450F-2007 - KICK AXLE AND SHIFT SHAFT - 1

YAMAHA YZ450F-2007 - KICK AXLE AND SHIFT SHAFT - 2
Extent of removal:
① Kick axle removal
③ Shift shaft removal
② Kick axle disassembly
④ Segment removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalKICK AXLE AND SHIFT SHAFT REMOVAL Oil pumpRefer to “OIL PUMP” section.
121Kick idle gear1Refer to “REMOVAL POINTS”.
2Kick axle assembly1
3Spring guide1
4Torsion spring1
5Ratchet wheel1
6Kick gear1
7Kick axle1
8Plain washer1
9Shift pedal1
10Shift shaft1
11Collar1
12Torsion spring1
  1. Remove:

  2. Kick axle assembly ①

NOTE: Unhook the torsion spring ② from the hole ⑧ in the crankcase.

EC4C3101

Shift guide and shift lever assembly

  1. Remove:

  2. Bolt (shift guide)

  3. Shift guide ①
  4. 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

  3. Segment ②

NOTE:

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

CAUTION:

If the segment gets an impact, it may be damaged. Take care not to give an impact to the segment when removing the bolt.

YAMAHA YZ450F-2007 - CAUTION: - 1

INSPECTION

EC4C4200

Kick axle and ratchet wheel

  1. Check:

  2. Ratchet wheel ① smooth movement Unsmooth movement Replace.

  3. Kick axle ② Wear/damage Replace.
  4. Spring ③ Broken Replace.

POINTS DE DEPOSE

Arbre de kick complet

  1. Déposer:

  2. Boulon (segment) ①

  3. Segment ②

Kick gear, kick idle gear and ratchet wheel

  1. Inspect:

  2. Kick gear ①

  3. Kick idle gear ②
  4. Ratchet wheel ③
    Gear teeth
  5. Ratchet teeth ⑥

Wear/damage Replace.

EC4B4400

Shift shaft

  1. Inspect:

  2. Shift shaft ①

Bend/damage Replace.

Spring ②

Broken Replace.

EC4C4100

Shift guide and shift lever assembly

  1. Inspect:

  2. Shift guide ①

  3. Shift lever ②
  4. Pawl ③
  5. Pawl pin ④
    Spring ⑤

Wear/damage Replace.

EC4B4500

Stopper lever

  1. Inspect:

  2. Stopper lever ①
    Wear/damage Replace.

  3. Torsion spring ②
    Broken Replace.

ASSEMBLY AND INSTALLATION

Segment

  1. Install:

  2. Segment ①

  3. Bolt (segment)

30 Nm (3.0 m·kg, 22 ft·lb)

NOTE:

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

CAUTION:

If the segment gets an impact, it may be damaged. Take care not to give an impact to the segment when tightening the bolt.

YAMAHA YZ450F-2007 - CAUTION: - 1

YAMAHA YZ450F-2007 - CAUTION: - 2

YAMAHA YZ450F-2007 - CAUTION: - 3

EC4B5111

Stopper lever

  1. Install:

  2. Torsion spring ①

  3. Plain washer ②
  4. Stopper lever ③
  5. Bolt (stopper lever) ④

YAMAHA YZ450F-2007 - Stopper lever - 1

10Nm(1.0m·kg,7.2ft·lb)

NOTE:

Align the stopper lever roller with the slot on segment.

Shift guide and shift lever assembly

  1. Install:

Spring ①
- Pawl pin ②
- Pawl ③

To shift lever ④.

NOTE:

Apply the engine oil on the springs, pawl pins and pawls.

  1. Install:

  2. Shift lever assembly ①

To shift guide ②.

ASSEMBLAGE ET MONTAGE

Segment

  1. Monter:

  2. Segment ①

  3. Boulon (segment)

30Nm(3,0m·kg,22ft·lb)

N.B.:

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

4. Install:

  • Bolt (shift guide) ①

YAMAHA YZ450F-2007 - Install: - 1

10Nm(1.0m·kg,7.2ft·lb)

EC4C5301

Shift shaft

1. Install:

  • Roller ①
    Collar ②
  • Torsion spring ③
  • Plain washer ④
  • Shift shaft ⑤

NOTE:

Apply the engine oil on the roller and shift shaft.

2. Install:

  • Shift pedal ①
  • Bolt (shift pedal)

12 Nm (1.2 m·kg, 8.7 ft·lb)

NOTE:

When installing the shift pedal onto the shift shaft, be sure that the center of the shift pedal is about 4.4 ~mm (0.17 in) ④ above the top of the footrest.

  1. Install:

  2. Kick gear ①

  3. Plain washer ②
  4. Circlip ③ New
  5. Ratchet wheel ④
    Spring ⑤
  6. Plain washer ⑥
  7. Circlip ⑦ New

To kick axle ⑧.

NOTE:

  • Apply the molybdenum disulfide oil on the inner circumferences of the kick gear and ratchet wheel.
  • Align the punch mark ⑧ on the ratchet wheel with the punch mark ⑥ on the kick axle.

YAMAHA YZ450F-2007 - NOTE: - 1

  1. Install:

  2. Torsion spring ①

To kick axle ②.

NOTE:

Make sure the stopper ⑧ of the torsion spring fits into the hole ⑥ on the kick axle.

YAMAHA YZ450F-2007 - NOTE: - 1

  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.

  1. Install:

  2. Kick axle assembly ①

  3. Plain washer ②

NOTE:

  • Apply the molybdenum disulfide grease on the contacting surfaces of the kick axle stopper ⑧ and ratchet wheel guide ③ .
  • Apply the engine oil on the kick axle.
  • Slide the kick axle assembly into the crankcase and make sure the kick axle stopper fits into the ratchet wheel guide.

YAMAHA YZ450F-2007 - NOTE: - 1

Arbre de kick complet

Turn the torsion spring clockwise and hook into the proper hole ⑧ in the crankcase.

Kick idle gear

  1. Install:

  2. Kick idle gear ①

  3. Plain washer ②
  4. Circlip ③ New

NOTE:

Install the kick idle gear with its depressed side @ toward you.
- Apply the engine oil on the kick idle gear inner circumference.

① CDI magneto removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCDI MAGNETO REMOVALSeat and fuel tankDisconnect the CDI magneto lead.Refer to “SEAT, FUEL TANK AND SIDE COVERS” section.
11Crankcase cover (left)1Use special tool.Refer to “REMOVAL POINTS”.
2Gasket1
3Dowel pin2
4Nut (rotor)1
5Rotor1
6Stator1
7Woodruff key1

VOLANT MAGNETIQUE CDI

YAMAHA YZ450F-2007 - VOLANT MAGNETIQUE CDI - 1

  1. Remove:

  2. Nut (rotor) ①

  3. Plain washer

  4. Remove:

  5. Rotor ①

Use the rotor puller ②.

YAMAHA YZ450F-2007 - VOLANT MAGNETIQUE CDI - 2

EC4L4000

INSPECTION

EC4L4101

CDI magneto

  1. Inspect:

  2. Rotor inner surface @

  3. Stator outer surface 包

Damage Inspect the crankshaft runout and crankshaft bearing. If necessary, replace CDI magneto and/or stator.

EC4L4200

Woodruff key

  1. Inspect:

  2. Woodruff key ①

Damage Replace.

EC4L5000

ASSEMBLY AND INSTALLATION

CDI magneto

  1. Install:

  2. Stator ①

  3. Screw (stator) ②

10 Nm (1.0 m·kg, 7.2 ft·lb)

NOTE:

  • Apply the sealant to the grommet of the CDI magneto lead.
  • Tighten the screws using the T30 bit.

YAMAHA YZ450F-2007 - NOTE: - 1

YAMAHA Bond No. 1215

(ThreeBond No. 1215):

90890-85505

POINTS DE DEPOSE

Rotor

  1. Déposer:

  2. Ecrou (rotor) ①
    Rondelle pleine

  1. Monter:

  2. Stator ①

  3. Vis (stator) ②

10Nm (1,0m· kg,7,2 ft·lb)

N.B.:

  • Clean the tapered portions of the crankshaft and rotor.
  • When installing the woodruff key, make sure that its flat surface ④ is in parallel with the crankshaft center line ⑥ .
  • When installing the rotor, align the keyway © of the rotor with the woodruff key.

YAMAHA YZ450F-2007 - Rotor - 1

YAMAHA YZ450F-2007 - Rotor - 2

YAMAHA YZ450F-2007 - Rotor - 3

3. Install:

  • Plain washer
  • Nut (rotor) ①

56 Nm (5.6 m·kg, 40 ft·lb)

4. Connect:

  • CDI magneto lead Refer to "CABLE ROUTING DIAGRAM" section in the CHAPTER 2.

5. Install:

Dowel pin
- O-ring New
- Gasket [crankcase cover (left)] New
- Crankcase cover (left) ①
- Hose holder (cylinder head breather hose) ②
- Bolt [crankcase cover (left)]

10Nm(1.0m·kg,7.2ft·lb)

NOTE:

  • Apply the lithium soap base grease on the O-ring.
  • Tighten the bolts in stage, using a crisscross pattern.

  • Monter:

  • Clavette demi-lune ①

  • Rotor ②

N.B.:

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalENGINE REMOVALHold the machine by placing the suitable stand under the frame.![]('img_url') Support the machine securely so there is no danger of it falling over.![]('img_url') Refer to "SEAT, FUEL TANK AND SIDE COVERS" section.
Seat and fuel tankRear shock absorberCarburetorExhaust pipe and silencerClutch cableRadiatorShift pedalCylinder head breather hoseDrain the engine oilIgnition coilDisconnect the CDI magneto lead.Engine guardRefer to "REAR SHOCK ABSORBER" section in the CHAPTER 5.Refer to "CARBURETOR" section.Refer to "EXHAUST PIPE AND SILENCER" section.Disconnect at engine side.Refer to "RADIATOR" section.Refer to "KICK AXLE AND SHIFT SHAFT" section.Refer to "CAMSHAFTS" section.Refer to "ENGINE OIL REPLACEMENT" section in the CHAPTER 3.

DEPOSE DU MOTEUR

Extent of removalOrderPart nameQ'tyRemarks
11Neutral switch1Refer to “REMOVAL POINTS”.
2Chain cover1
3Nut (drive sprocket)1
4Lock washer1
5Drive sprocket1
6Clip1
7Bolt (brake pedal)1
8Brake pedal1
9Engine upper bracket (right)1
10Engine upper bracket (left)1
11Engine lower bracket2
12Engine mounting bolt3
13Pivot shaft1Refer to “REMOVAL POINTS”.
14Engine1
  1. Remove:

  2. Nut (drive sprocket) ①

  3. Lock washer ②

NOTE:

  • Straighten the lock washer tab.
  • Loosen the nut while applying the rear brake.

  • Remove:

  • Drive sprocket ①

  • Drive chain ②

NOTE:

Remove the drive sprocket together with the drive chain.

EC4M3301

Engine removal

  1. Remove:

  2. 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:

  2. Engine ①

From right side.

NOTE:

Make sure that the couplers, hoses and cables are disconnected.

POINTS DE DEPOSE

Couronne arrière

ASSEMBLY AND INSTALLATION

Engine installation

  1. Install:

  2. Engine ①
    Install the engine from right side.

  3. Pivot shaft ②
    85 Nm (8.5 m·kg, 61 ft·lb)
  4. Engine mounting bolt (lower) ③
    53 Nm (5.3 m·kg, 38 ft·lb)
  5. Engine lower bracket ④
  6. Bolt (engine lower bracket) ⑤
    34 Nm (3.4 m·kg, 24 ft·lb)
  7. Patch ⑥
  8. Engine mounting bolt (front) ⑦
    53 Nm (5.3 m · kg, 38 ft · lb)
  9. Engine upper bracket (right) ⑧
  10. Engine upper bracket (left) ⑨
  11. Bolt (engine upper bracket) 10
    55Nm(5.5m·kg,40ft·lb)
  12. Engine mounting bolt (upper) ⑪
    55Nm (5.5m· kg,40ft· lb)

NOTE:

  • Apply the molybdenum disulfide grease on the pivot shaft.
    Install the patch with the claw ⑧ facing outside the chassis.

YAMAHA YZ450F-2007 - NOTE: - 1

Brake pedal

  1. Install:

Spring ①
- Brake pedal ②
- O-ring ③ New
- Bolt (brake pedal) ④

26 Nm (2.6 m·kg, 19 ft·lb)

  • Clip ⑤

NOTE:

Apply the lithium soap base grease on the bolt, O-rings and brake pedal bracket.

YAMAHA YZ450F-2007 - NOTE: - 1

Drive sprocket

  1. Install:

  2. Drive sprocket ①

  3. Drive chain ②

NOTE:

Install the drive sprocket together with the drive chain.

26Nm(2,6m·kg,19ft·lb)

  • Clip ⑤

N.B.:

Tighten the nut while applying the rear brake.

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

  2. Install:

  3. Chain guide

  4. Chain cover ①
  5. Screw (chain cover) ②

8Nm(0.8m·kg,5.8ft·lb)

  1. Install:

Spring ①
Pin ②
- O-ring ③ New
- Neutral switch ④
- Screw (neutral switch) ⑤

YAMAHA YZ450F-2007 - N.B.: - 1

4Nm(0.4m·kg,2.9ft·lb)

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

  1. Monter:

CRANKCASE AND CRANKSHAFT

CRANKCASE AND CRANKSHAFT

YAMAHA YZ450F-2007 - CRANKCASE AND CRANKSHAFT - 1

Extent of removal:
① Crankcase separation
② Crankshaft removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCRANKCASE SEPARATIONEnginePistonBalancerKick axle assemblySegmentStatorRefer to “ENGINE REMOVAL” section.Refer to “CYLINDER AND PISTON” section.Refer to “BALANCER” section.Refer to “KICK AXLE AND SHIFT SHAFT” section.Refer to “CDI MAGNETO” section.
12Timing chain guide (rear)1Refer to “REMOVAL POINTS”.
34Timing chainBolt (50 mm)7
56Bolt (60 mm)2
6Hose guideBolt (80 mm)3
Hose guide1
Extent of removalOrderPart nameQ'tyRemarks
7Crankcase (right)1Refer to “REMOVAL POINTS”.
8Crankcase (left)1
9Oil strainer1
10Balancer shaft1Refer to “REMOVAL POINTS”.
11Crankshaft1Use special tool.
Refer to “REMOVAL POINTS”.

Extent of removal:
① Crankcase bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalCRANKCASE BEARING REMOVALTransmissionShift cam and shift forkRefer to “TRANSMISSION, SHIFT CAM AND SHIFT FORK” section.
1212Oil sealBearing310Refer to “REMOVAL POINTS”.
  1. Separate:

  2. Crankcase (right)

  3. 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:

  • Place the crankcase with its left side downward and split it by inserting a screwdriver tip into the splitting slit ⑧ in the crankcase.
  • Lift the crankcase (right) horizontally while lightly patting the case splitting slit and engine mounting boss using a soft hammer, and leave the crankshaft and transmission with the crankcase (left).

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 the cases do not separate, check for a remaining case screw or fitting. Do not force.

  • Remove the dowel pins and O-ring.

YAMAHA YZ450F-2007 - CAUTION: - 1

Balancer shaft

  1. Remove:

Balancer shaft ①

NOTE:

Remove the balancer shaft with its flat side ⑧ facing the crankshaft.

NOTE: Install the crankcase separating tool as shown.

CAUTION:

Do not use a hammer to drive out the crankshaft.

Crankshaft bearing

  1. Remove:

  2. Bearing ①

NOTE:

  • Remove the bearing from the crankcase by pressing its inner race.
  • Do not use the removed bearing.

INSPECTION

Timing chain and timing chain guide

  1. Inspect:

  2. Timing chain

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

  1. Inspect:

  2. Timing chain guide

Wear/damage Replace.

EC4N4101

Crankcase

  1. Inspect:

  2. Contacting surface @

Scratches Replace.

  • Engine mounting boss ⑥, crankcase

Cracks/damage Replace.

Vilebrequin

  1. Déposer:

Vilebreguin ①

  1. Inspect:

  2. Bearing

  3. Rotate inner race with a finger.
  4. Rough spot/seizure Replace.

  5. Inspect:

  6. Oil seal Wear/damage Replace.

EC4N4201 Crankshaft

  1. Measure:

  2. Runout limit (a)

  3. Small end free play limit ⑥
  4. Connecting rod big end side clearance ©
  5. Crank width ⑥ Out of specification Replace. Use the dial gauge and a thickness gauge.
Dial gauge and stand: YU-3097/90890-01252
Standard<Limit>
Runout limit:0.03 mm (0.0012 in)0.05 mm (0.002 in)
Small end free play:0.4 ~ 1.0 mm (0.016 ~ 0.039 in)2.0 mm (0.08 in)
Side clearance:0.15 ~ 0.45 mm (0.0059 ~ 0.0177 in)0.50 mm (0.02 in)
Crack width:61.95 ~ 62.00 mm (2.439 ~ 2.441 in)-

YAMAHA YZ450F-2007 - EC4N4201 Crankshaft - 1

Oil strainer

  1. Inspect:

  2. Oil strainer Damage Replace.

  3. Controller:

Roulement

ASSEMBLY AND INSTALLATION

Crankshaft bearing

  1. Install:

  2. Bearing
    New

  3. Bearing stopper
  4. Bolt (bearing stopper)

YAMAHA YZ450F-2007 - Crankshaft bearing - 1

10Nm(1.0m·kg,7.2ft·lb)

  • Screw (bearing stopper)

YAMAHA YZ450F-2007 - Crankshaft bearing - 2

10Nm(1.0m·kg,7.2ft·lb)

  • Screw [bearing stopper (crankshaft)] ①
    14 Nm (1.4 m · kg, 10 ft · lb)

To crankcase (left and right).

NOTE:

  • Install the bearing by pressing its outer race parallel.
  • To prevent the screw [bearing stopper (crankshaft)] from becoming loose, crush the screw head periphery ④ into the concave ⑥ using a punch etc. In so doing, take care not to damage the screwdriver receiving hole in the screw head.

YAMAHA YZ450F-2007 - NOTE: - 1

Crankshaft

  1. Install:

Crankshaft ①

Use the crankshaft installing tool ②, ③, ④ and ⑤.

YAMAHA YZ450F-2007 - Crankshaft - 1

Crankshaft installing pot ② : YU- 90050/90890- 01274

Crankshaft installing bolt ③ : YU-90050/90890-01275

Adaptor (M12) ④: YU-90063/90890-01278

Spacer (crankshaft installer) ⑤ : YM-91044/90890-04081

YAMAHA YZ450F-2007 - Crankshaft - 2

YAMAHA YZ450F-2007 - Crankshaft - 3

For USA and CDN
Except for USA and CDN

ASSEMBLAGE ET MONTAGE

  • Hold the connecting rod at top dead center with one hand while turning the nut of the installing tool with the other. Operate the installing tool until the crankshaft bottoms against the bearing.
  • Before installing the crankshaft, clean the contacting surface of crankcase.

CAUTION:

Do not use a hammer to drive in the crankshaft.

YAMAHA YZ450F-2007 - CAUTION: - 1

YAMAHA YZ450F-2007 - CAUTION: - 2

YAMAHA YZ450F-2007 - CAUTION: - 3

2. Check:

  • Shifter operation
    Transmission operation

Unsmooth operation Repair.

3. Install:

  • Oil strainer ①
  • Bolt (oil strainer) ②

10 Nm (1.0 m·kg, 7.2 ft·lb)

4. Apply:

  • Sealant

On the crankcase (right).

YAMAHA YZ450F-2007 - Apply: - 1

YAMAHA Bond No. 1215

(ThreeBond 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:

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

6. Tighten:

  • Bolt (hose guide) ①
  • Bolt (crankcase)

12 Nm (1.2 m·kg, 8.7 ft·lb)

NOTE:

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

7. Install:

  • Timing chain
  • Timing chain guide (rear)
  • Bolt (timing chain guide)

10 Nm (1.0 m·kg, 7.2 ft·lb)

8. Remove:

  • Sealant

Forced out on the cylinder mating surface.

9. Apply:

Engine oil

To the crank pin, bearing and oil delivery hole.

10. Check:

  • Crankshaft and transmission operation.

Unsmooth operation Repair.

  1. Monter:

Goujon ①
- Joint torque ②
Carter (droit)

New

TRANSMISSION, SHIFT CAM AND SHIFT FORK

TRANSMISSION, SHIFT CAM AND SHIFT FORK

YAMAHA YZ450F-2007 - TRANSMISSION, SHIFT CAM AND SHIFT FORK - 1
Extent of removal:

① Shift fork, shift cam, main axle and drive axle removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalTRANSMISSION, SHIFT CAM AND SHIFT FORK REMOVAL Engine Separate the crankcase.Refer to “ENGINE REMOVAL” section. Refer to “CRANKCASE AND CRANK-SHAFT” section.
11Main axle1Refer to “REMOVAL POINTS”.
2Drive axle1
3Shift cam1
4Shift fork 31
5Shift fork 21
6Shift fork 11
7Collar1

BOITE DE VITESSES, TAMBOUR ET FOURCHETTES DE SELECTION BOITE DE VITESSES, TAMBOUR ET FOURCHETTES DE SELECTION

  1. Remove:

  2. Main axle ①

  3. Drive axle ②
  4. Shift cam
  5. Shift fork 3
  6. Shift fork 2
  7. Shift fork 1

NOTE:

  • Remove assembly with the collar ③ installed to the crankcase.
  • Remove assembly carefully. Note the position of each part. Pay particular attention to the location and direction of shift forks.
  • Remove the main axle, drive axle, shift cam and shift fork all together by tapping lightly on the transmission drive axle with a soft hammer.

YAMAHA YZ450F-2007 - NOTE: - 1

EC4H4000

INSPECTION

EC4H4200

Gears

  1. Inspect:

  2. Matching dog @
    Gear teeth

  3. Shift fork groove © Wear/damage Replace.

YAMAHA YZ450F-2007 - Gears - 1

  1. Inspect:

  2. O-ring ① Damage → Replace.

  3. Check:

  4. Gears movement Unsmooth movement → Repair or replace.

YAMAHA YZ450F-2007 - Gears - 2

EC4H4600

Bearing

  1. Inspect:

  2. Bearing ①

    • Rotate inner race with a finger.
    • Rough spot/seizure Replace.

POINTS DE DEPOSE

Boîte de vitesses

  1. Inspect:

  2. Shift fork ①

Wear/damage/scratches Replace.

  1. Inspect:

  2. Shift cam ①

  3. Segment ②

Bend/wear/damage Replace.

  1. Check:

  2. Shift fork movement

Unsmooth operation Replace shift fork.

NOTE:

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

ASSEMBLY AND INSTALLATION

Transmission

  1. Install:

  2. 5th pinion gear (21T) ①

  3. 3rd pinion gear (18T) ②
  4. Collar ③
  5. 4th pinion gear (22T) ④
  6. 2nd pinion gear (15T) ⑤

To main axle ⑥.

NOTE:

Apply the molybdenum disulfide oil on the inner and end surface of the idler gear and on the inner surface of the sliding gear, then install.

  • Collar ①
  • 2nd wheel gear (23T) ②
  • 4th wheel gear (24T) ③
  • 3rd wheel gear (23T) ④
  • 5th wheel gear (20T) ⑤
    Collar ⑥
  • 1st wheel gear (27T) ⑦
  • O-ring ⑧ New

To drive axle ⑨.

NOTE:

  • Apply the molybdenum disulfide oil on the inner and end surface of the idler gear and on the inner surface of the sliding gear, then install.
  • Apply the lithium soap base grease on the O-ring.

3. Install:

  • Plain washer ①
  • Circlip ② New

NOTE:

  • Be sure the circlip sharp-edged corner ④ is positioned opposite side to the plain washer and gear ⑥ .
    Install the circlip with its ends © settled evenly on the spline crests.

4. Install:

  • Collar ①

NOTE:

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

  • Monter:

  • Entretoise épaulée ①

  • Pignon de 2ème (23T) ②
  • Pignon de 4ème (24T) ③
  • Pignon de 3ème (23T) ④
  • Pignon de 5ère (20T) ⑤
  • Entretoise épaulée ⑥
  • Pignon de 1ère (27T) ⑦
  • Joint torque ⑧ New
  • Shift fork 1 (L) ①
  • Shift fork 2 (C) ②
  • Shift fork 3 (R) ③
  • Shift cam ④ To main axle and drive axle.

NOTE:

  • Apply the molybdenum disulfide oil on the shift fork grooves.
  • Apply engine oil to the shift cam groove, bearing contact surface and shift fork shaft.
  • Mesh the shift fork #1 (L) with the 4th wheel gear ⑤ and #3 (R) with the 5th wheel gear ⑦ on the drive axle.
  • Mesh the shift fork #2 (C) with the 3rd pinion gear ⑥ on the main axle.

6. Install:

Transmission assembly ①

To crankcase (left) ②.

NOTE:

Apply the engine oil on the bearings and guide bars.

7. Check:

  • Shifter operation
    Transmission operation Unsmooth operation Repair.

  • Monter:

  • Fourchette de seLECTION 1 (G) ①

  • Fourchette 2 (C) ②
  • Fourchette 3 (D) ③
    Tambour ④

① Front wheel removal
③ Brake disc removal

② Wheel bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalFRONT WHEEL REMOVALHold the machine by placing the suitable stand under the engine.WARNINGSupport the machine securely so there is no danger of it falling over.
1312345678Bolt (axle holder)4Only loosening.
Nut (front wheel axle)1
Front wheel axle1
Front wheel1
Collar2
Oil seal2
Bearing2Refer to “REMOVAL POINTS”.
Brake disc1

CHÄSSIS

ROUE AVANT ET ROUE ARRIERE

ROUE AVANT

Extent of removal:
YAMAHA YZ450F-2007 - ROUE AVANT - 1
① Rear wheel removal
③ Brake disc removal

② Wheel bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalREAR WHEEL REMOVALHold the machine by placing the suitable stand under the engine.WARNINGSupport the machine securely so there is no danger of it falling over.
131Nut (rear wheel axle)1Refer to “REMOVAL POINTS”.
2Rear wheel axle1
3Chain puller2
4Rear wheel1
5Collar2
6Driven sprocket1
7Oil seal2
8Circlip1
9Bearing2Refer to “REMOVAL POINTS”.
10Brake disc1

ROUE AVANT ET ROUE ARRIERE VORDER- UND HINTERRAD

YAMAHA YZ450F-2007 - ROUE AVANT ET ROUE ARRIERE VORDER- UND HINTERRAD - 1

ROUE ARRIERE

Push the wheel forward and remove the drive chain ②.

EC513201

Wheel bearing (if necessary)

  1. Remove:

  2. Bearing ①

NOTE:

Remove the bearing using a general bearing puller ②.

EC594000

INSPECTION

EC514100

Wheel

  1. Measure:

  2. Wheel runout

Out of limit Repair/replace.

YAMAHA YZ450F-2007 - Wheel - 1

Wheel runout limit:

Radial ①: 2.0 mm (0.08 in)

Lateral ②: 2.0 ~mm (0.08 in)

  1. Inspect:

  2. Bearing

Rotate inner race with a finger.

Rough spot/seizure Replace.

NOTE:

Replace the bearings, oil seal and wheel collar as a set.

POINTS DE DEPOSE

Roue arrière

  1. Déposer:

  2. Roue ①

N.B.:

  1. Measure:

  2. Wheel axle bends

Out of specification Replace.

Use the dial gauge ①.

YAMAHA YZ450F-2007 - Roue arrière - 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 YZ450F-2007 - Roue arrière - 2

WARNING

Do not attempt to straighten a bent axle.

YAMAHA YZ450F-2007 - Roue arrière - 3

EC594200

Brake disc

  1. Measure:

  2. Brake disc deflection (only rear brake disc)

Use the dial gauge ①.

Out of specification Inspect wheel runout.

If wheel runout is in good condition, replace the brake disc.

Disc deflection limit:
Standard<Limit>
Rear0.15 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)

Axe de roue

1. Mesurer:

ASSEMBLY AND INSTALLATION

Front wheel

  1. Install:

  2. Bearing (left) ①

  3. Spacer ②
  4. Bearing (right) ③
  5. Oil seal ④ New

NOTE:

  • Apply the lithium soap base grease on the bearing and oil seal lip when installing.
  • Use a socket that matches the outside diameter of the race of the bearing.
  • Left side of bearing shall be installed first.
  • Install the oil seal with its manufacture's marks or numbers facing outward.

CAUTION:

Do not strike the inner race of the bearing. Contact should be made only with the outer race.

  1. Install:

  2. Brake disc ①

  3. Bolt (brake disc) ②

YAMAHA YZ450F-2007 - CAUTION: - 1

12 Nm (1.2 m·kg, 8.7 ft·lb)

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

  1. Install:

  2. Collar ①

NOTE:

  • Apply the lithium soap base grease on the oil seal lip.
    Install the collars with their projections ⑧ facing the wheel.

  • Install:

  • Wheel

NOTE:

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

ASSEMBLAGE ET MONTAGE

Roue avant

1. Monter:

  1. Install:

  2. Wheel axle ①

NOTE: Apply the lithium soap base grease on the wheel axle.

  1. Install:

  2. Nut (wheel axle) ①

105 Nm (10.5 m·kg, 75 ft·lb)

  1. Tighten:

  2. Bolt (axle holder) ①

21Nm(2.1m·kg,15ft·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. Bearing (right) ①

  3. Circlip ② N
  4. Spacer ③
  5. Bearing (left) ④
  6. Oil seal ⑤ New

NOTE:

  • Apply the lithium soap base grease on the bearing and oil seal lip when installing.
  • Install the bearing with seal facing outward.
  • Use a socket that matches the outside diameter of the race of the bearing.
  • Right side of bearing shall be installed first.
  • Install the oil seal with its manufacture's marks or numbers facing outward.

CAUTION:

Do not strike the inner race of the bearing. Contact should be made only with the outer race.

YAMAHA YZ450F-2007 - CAUTION: - 1

YAMAHA YZ450F-2007 - CAUTION: - 2

  1. Install:

  2. Brake disc ①

  3. Bolt (brake disc) ②

YAMAHA YZ450F-2007 - CAUTION: - 3

14 Nm (1.4 m·kg, 10 ft·lb)

NOTE:

Tighten the bolts in stage, using a crisscross pattern.

  1. Install:

  2. Driven sprocket ①

  3. Bolt (driven sprocket) ②
  4. Plain washer (driven sprocket) ③
  5. Nut (driven sprocket) ④

42 Nm (4.2 m · kg, 30 ft · lb)

NOTE:

Tighten the nuts in stage, using a crisscross pattern.

Roue arrière

1. Monter:

Apply the lithium soap base grease on the oil seal lip.

  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.

  1. Install:

  2. Chain puller (left) ①

  3. Wheel axle ②

NOTE:

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

  • Install:

  • Chain puller (right) ①

  • Plain washer ②
  • Nut (wheel axle) ③

NOTE:

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

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

19 Nm (1.9 m · kg, 13 ft · lb)

ROUE AVANT ET ROUE ARRIERE VORDER- UND HINTERRAD

YAMAHA YZ450F-2007 - ROUE AVANT ET ROUE ARRIERE VORDER- UND HINTERRAD - 1

9. Régler:

  • Tension de la châne de transmission @

YAMAHA YZ450F-2007 - Régler: - 1

② Caliper removal
YAMAHA YZ450F-2007 - Régler: - 2
(1) Brake hose removal
③ Master cylinder removal

Extent of removal:

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalFRONT BRAKE REMOVALHold the machine by placing the suitable stand under the engine.Drain the brake fluid.WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “REMOVAL POINTS”.
123123Brake hose holder (protector)2
2Brake hose holder (caliper)1
3Union bolt2
4Brake hose1
5Pad pin plug1Remove when loosening the pad pin. Loosen when disassembling the caliper.
6Pad pin1
7Caliper1
8Brake lever1
9Master cylinder bracket1
10Master cylinder1

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN

YAMAHA YZ450F-2007 - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN - 1

FREIN AVANT ET FREIN ARRIERE

FREIN AVANT

① Master cylinder removal
③ Caliper removal

② Brake hose removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalREAR BRAKE REMOVALHold the machine by placing the suitable stand under the engine.Rear wheelDrain the brake fluid.WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “FRONT WHEEL AND REAR WHEEL” section.Refer to “REMOVAL POINTS”.
1234567812345678Brake pedalMaster cylinderBrake hose holderUnion boltBrake hosePad pin plugPad pinCaliper112221111Remove when loosening the pad pin.Loonen when disassembling the caliper.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN

YAMAHA YZ450F-2007 - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN - 1

FREIN ARRIERE

① Front caliper disassembly

② Rear caliper disassembly

Extent of removalOrderPart nameQ'tyRemarks
1 2① ② ③ ④ ⑤ ⑥CALIPER DISASSEMBLY Pad pin Brake pad Pad support Caliper piston Dust seal Piston sealABRefer to “REMOVAL POINTS”.
11
22
11
21
21
21

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN

YAMAHA YZ450F-2007 - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN - 1

DEMONTAGE DE L'ETRIER DE FREIN

A Avant
[8] Arrière

① Front master cylinder disassembly

② Rear master cylinder disassembly

Extent of removalOrderPart nameQ'tyRemarks
1 2 3 4 5 6 7 8① ② ③ ④ ⑤ ⑥ ⑦ ⑧MASTER CYLINDER DISAS-SEMBLY Master cylinder cap Diaphragm Reservoir float Master cylinder boot Circlip Plain washer Push rod Master cylinder kit1 1 1 1 1 1 1 1 1 1 1 1 1Use a long nose circlip pliers.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN

YAMAHA YZ450F-2007 - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN - 1

DEMONTAGE DU MAITRE-CYLINDRE DE FREIN

A Avant
[8] Arrière

  • Master cylinder cap ① [Rear]
  • Master cylinder cap ①
  • Protector

NOTE:

Do not remove the diaphragm.

A Front
Rear

  1. Connect the transparent hose ② to the bleed screw ① 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:

  2. 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

POINTS DE DEPOSE

Liquide de frein

  1. Remove:

  2. Dust seal ①

  3. Piston seal ②

NOTE:

Remove the piston seals and dust seals by pushing them with a finger.

CAUTION:

Never attempt to pry out piston seals and dust seals.

WARNING

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

A Front
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:

  2. Diaphragm ① Crack/damage Replace.

A Front
Rear

  1. Inspect: (front brake only)

  2. Reservoir float ① Damage Replace.

Kit joint de piston

  1. Déposer:

  2. Joint antipoussière ①

  3. Joint de piston ②

N.B.:

  1. Inspect:

  2. Master cylinder piston ①

  3. Master cylinder cup ②

Wear/damage/score marks Replace master cylinder kit.

A Front
Rear

EC534214

Caliper

  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.

YAMAHA YZ450F-2007 - Caliper - 1

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

YAMAHA YZ450F-2007 - ASSEMBLY AND INSTALLATION - 1

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.

  • Controller:

  • Piston du maître-cylindre ①
    Coupelle du maître-cylindre ②

  1. Clean:

  2. Caliper

  3. Piston seal
  4. Dust seal
  5. Caliper piston Clean them with brake fluid.

  6. Install:

  7. Piston seal ① New

  8. Dust seal ② New

WARNING

Always use new piston seals and dust seals.

NOTE:

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

A Front
Rear

  1. Install:

  2. Caliper piston ①

NOTE:

Apply the brake fluid on the piston wall.

CAUTION:

  • Install the piston with its shallow depressed side ⑧ facing the caliper.
  • Never force to insert.

A Front
Rear

EC5A5700

Front caliper

  1. Install:

  2. Pad support ①

  3. Brake pad ②
  4. Pad pin ③

NOTE:

Install the brake pads with their projections into the caliper recesses ⑥
- Temporarily tighten the pad pin at this point.

  1. Install:

  2. Pad support ①

  3. Brake pad ②
  4. Pad pin ③

NOTE:

Install the brake pads with their projections 包 into the caliper recesses ⑥
- Temporarily tighten the pad pin at this point.

YAMAHA YZ450F-2007 - NOTE: - 1

  1. Install:

  2. Disc cover ①

  3. Bolt (disc cover) ②

10Nm(1.0m·kg,7.2ft·lb)

  1. Install:

  2. Caliper ①
    Rear wheel ②

Refer to “FRONT WHEEL AND REAR WHEEL” section.

  1. Tighten:

  2. Pad pin ③

18 Nm (1.8 m·kg, 13 ft·lb)

  1. Install:

  2. Pad pin plug ④

3Nm(0.3m·kg,2.2ft·lb)

YAMAHA YZ450F-2007 - NOTE: - 2

Master cylinder kit

  1. Clean:

  2. Master cylinder

  3. Master cylinder kit

Clean them with brake fluid.

  1. Install:

  2. Master cylinder cup (primary) ①

  3. 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 dia. side.

A Front
Rear

  • Master cylinder kit ①
  • Plain washer ②
  • Circlip ③
  • Master cylinder boot ④

To master cylinder ⑤.

[Rear]

  • Master cylinder kit ①
  • Push rod ②
  • Circlip ③
  • Master cylinder boot ④

To master cylinder ⑤.

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 YZ450F-2007 - WARNING - 1

EC5A5310

Front master cylinder

  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 ⑧ face upward.
- First tighten the bolts on the upper side of the master cylinder bracket, and then tighten the bolts on the lower side.

  1. Monter:

[Avant]

NOTE: Apply the lithium soap base grease on the brake lever sliding surface, bolt and contacting surface of the master cylinder piston.

Rear master cylinder

1. Install:

Copper washer ① New
- Brake hose ②
- Union bolt ③

30 Nm (3.0 m · kg, 22 ft · lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose so that its pipe portion ⑧ directs as shown and lightly touches the projection ⑥ on the master cylinder.

2. Install:

  • Master cylinder ①
  • Bolt (master cylinder) ②

10 Nm (1.0 m·kg, 7.2 ft·lb)

3. Install:

Spring ①
- Brake pedal ②
- O-ring ③ New
- Bolt (brake pedal) ④

26 Nm (2.6 m·kg, 19 ft·lb)

  • Clip ⑤

NOTE: Apply the lithium soap base grease on the bolt, O-ring and brake pedal bracket.

2. Monter:

6Nm(0,6m·kg,4,3ft·lb)

26Nm(2,6m·kg,19ft·lb)

  • Clip ⑤

N.B.:

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

Front brake hose

1. Install:

Copper washer ① New
- Brake hose ②
- Union bolt ③

30 Nm (3.0 m · kg, 22 ft · lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose so that its pipe portion ⑧ directs as shown and lightly touches the projection 6 on the caliper.

2. Install:

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

10Nm(1.0m·kg,7.2ft·lb)

3. Install:

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

7Nm(0.7m·kg,5.1ft·lb)

NOTE:

Align the top ⑧ of the brake hose holder with the paint ⑥ of the brake hose.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN

YAMAHA YZ450F-2007 - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN - 1

4. Monter:

  1. Pass the brake hose through the cable guide ①.

  2. Install:

Copper washer ① New
- Brake hose ②
- Union bolt ③

30 Nm (3.0 m·kg, 22 ft·lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose so that its pipe portion ⑧ directs as shown and lightly touches the projection ⑥ on the master cylinder.

Rear brake hose

  1. Install:

Copper washer ① New
- Brake hose ②
- Union bolt ③

30 Nm (3.0 m · kg, 22 ft · lb)

WARNING

Always use new copper washers.

CAUTION:

Install the brake hose so that its pipe portion ⑧ directs as shown and lightly touches the projection 6 on the caliper.

FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN

YAMAHA YZ450F-2007 - FREIN AVANT ET FREIN ARRIERE VORDER- UND HINTERRADBREMSEN - 1

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

2Nm(0.2m·kg,1.4ft·lb)

CAUTION:

After installing the brake hose holders, make sure the brake hose does not contact the spring (rear shock absorber). If it does, correct its twist.

Brake fluid

1. Fill:

  • Brake fluid

Until the fluid level reaches "LOWER" level line (a) .

YAMAHA YZ450F-2007 - Fill: - 1

Recommended brake fluid: DOT #4

WARNING

  • Use only the designated quality brake fluid:

otherwise, the rubber seals may deteriorate, causing leakage and poor brake performance.

  • Refill with the same type of brake fluid; mixing fluids may result in a harmful chemical reaction and lead to poor performance.
  • Be careful that water does not enter the master cylinder when refilling. Water will significantly lower the boiling point of the fluid and may result in vapor lock.

CAUTION:

Brake fluid may erode painted surfaces or plastic parts. Always clean up spilled fluid immediately.

A Front
Rear

2. Monter:

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

2Nm (0,2m· kg,1,4ft· lb)

ATTENTION:

ING" section in the CHAPTER 3.

3. Inspect:

  • Brake fluid level

Fluid at lower level Fill up.

Refer to "BRAKE FLUID LEVEL INSPEC-

TION" section in the CHAPTER 3.

YAMAHA YZ450F-2007 - Inspect: - 1

YAMAHA YZ450F-2007 - Inspect: - 2

YAMAHA YZ450F-2007 - Inspect: - 3

4. Install:

[Front]

  • Reservoir float
  • Diaphragm
  • Master cylinder cap ①
  • Screw (master cylinder cap) ②

2Nm(0.2m·kg,1.4ft·lb)

[Rear]

  • Diaphragm
  • Master cylinder cap ①
  • Bolt (master cylinder cap) ②

2Nm(0.2m·kg,1.4ft·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. Protector ①

  3. Bolt (protector) ②

7Nm(0.7m·kg,5.1ft·lb)

YAMAHA YZ450F-2007 - CAUTION: - 1
Extent of removal:
① Front fork removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalFRONT FORK REMOVALHold the machine by placing the suitable stand under the engine.WARNINGSupport the machine securely so there is no danger of it falling over.Refer to “FRONT WHEEL AND REAR WHEEL” section.Refer to “FRONT BRAKE AND REAR BRAKE” section.Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4.
Front wheel
Front caliper
Number plate
12Protector1Only loosening.
Pinch bolt (handle crown)2Loosen when disassembling the front fork.Use special tool.Refer to “REMOVAL POINTS”.
3Damper assembly1
4Pinch bolt (under bracket)2Only loosening.
5Front fork1

FOURCHE

YAMAHA YZ450F-2007 - FOURCHE - 1
Extent of removal:
① Oil seal removal
② Damper assembly removal

Extent of removalOrderPart nameQ'tyRemarks
12FRONT FORK DISASSEMBLY ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫Adjuster Fork spring Dust seal Stopper ring Inner tube Outer tube Piston metal Slide metal Oil seal washer Oil seal Base valve Damper assembly1 1 1 1 1 1 1 1 1 1 1 1 1 1Drain the fork oil. Use special tool. Refer to “REMOVAL POINTS”. Refer to “REMOVAL POINTS”. Drain the fork oil. Use special tool. Refer to “REMOVAL POINTS”.

DEMONTAGE DE LA FOURCHE

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 base valves or front forks, be sure to extract the air from the air chamber completely.

YAMAHA YZ450F-2007 - CAUTION: - 1

EC553000

REMOVAL POINTS

Damper assembly

  1. Loosen:

  2. Damper assembly ①

NOTE:

Before removing the front fork from the machine, loosen the damper assembly with the cap bolt ring wrench ②.

YAMAHA YZ450F-2007 - Damper assembly - 1

Cap bolt ring wrench:

YM-01501/90890-01501

REMARQUES CONCERNANT LA MANIPULATION

N.B.:

  1. Drain the outer tube of its front fork oil at its top.
  2. Loosen:

  3. Adjuster ①

  4. Remove:

  5. Adjuster ①

NOTE:

While compressing the inner tube ②, set the cap bolt ring wrench ④ between the inner tube and locknut ③.
- Hold the locknut and remove the adjuster.

CAUTION:

Do not remove the locknut as the damper rod may go into the damper assembly and not be taken out.

YAMAHA YZ450F-2007 - CAUTION: - 1

Cap bolt ring wrench: YM-01501/90890-01501

YAMAHA YZ450F-2007 - CAUTION: - 2

YAMAHA YZ450F-2007 - CAUTION: - 3

EC553201

Inner tube

  1. Remove:

  2. Dust seal ①

  3. Stopper ring ②

Using slotted-head screwdriver.

CAUTION:

Take care not to scratch the inner tube.

  1. Remove:

  2. Inner tube ①

Oil seal removal steps:

  • Push in slowly ⑧ 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.
  1. Remove:

  2. Base valve ①

From damper assembly ②.

NOTE:

Hold the damper assembly with the cap bolt ring wrench ③ and use the cap bolt wrench ④ to remove the base valve.

YAMAHA YZ450F-2007 - NOTE: - 1

Cap bolt wrench:

YM-01500/90890-01500

Cap bolt ring wrench:

YM-01501/90890-01501

YAMAHA YZ450F-2007 - NOTE: - 2

EC554000

INSPECTION

Damper assembly

  1. Inspect:

  2. Damper assembly ①

Bend/damage Replace.

  • O-ring ②

Wear/damage Replace.

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.

Soupape de base

  • Fork spring free length @

Out of specification Replace.

Fork spring free length:
Standard<Limit>
454 mm (17.9 in)449 mm (17.7 in)

Soupape de base

  1. Controller:

  2. Soupape de base ①

Usure/endommagement Remplacer.

Encrasse Nettoyer.

  • Joint torque ②

Usure/endommagement Remplacer.

  1. Inspect:

  2. Inner tube surface Score marks Repair or replace. Use #1,000 grit wet sandpaper. Damaged oil lock piece Replace.

  3. Inner tube bends Out of specification Replace. Use the dial gauge ①.

YAMAHA YZ450F-2007 - Soupape de base - 1

Inner tube bending limit: 0.2 mm (0.008 in)

NOTE:

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

YAMAHA YZ450F-2007 - Soupape de base - 2

WARNING

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

YAMAHA YZ450F-2007 - WARNING - 1

EC554600

Outer tube

  1. Inspect:

  2. Outer tube ① Score marks/wear/damage Replace.

YAMAHA YZ450F-2007 - Outer tube - 1

Adjuster

  1. Inspect:

  2. Adjuster ①

  3. O-ring ② Wear/damage Replace.

Tube plongeur

1. Controller:

ASSEMBLY AND INSTALLATION

Front fork assembly

  1. Wash the all parts in a clean solvent.
  2. Stretch the damper assembly fully.

YAMAHA YZ450F-2007 - Front fork assembly - 1

  1. Fill:

  2. Front fork oil ①

To damper assembly.

YAMAHA YZ450F-2007 - Front fork assembly - 2

Recommended oil:

Suspension oil "S1"

Oil capacity:

195 cm³ (6.86 Imp oz, 6.59 US oz)

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 YZ450F-2007 - CAUTION: - 1

  1. After filling, pump the damper assembly ① slowly up and down (about 200 ~mm (7.9 in) stroke) several times to bleed the damper assembly of air.

NOTE:

Be careful not to excessive full stroke. A stroke of 200 ~mm (7.9 in) or more will cause air to enter. In this case, repeat the steps 2 to 4.

ASSEMBLAGE ET MONTAGE

Fourche complete

  1. Measure:

  2. Oil level (left and right) ⑧

Out of specification Adjust.

YAMAHA YZ450F-2007 - Fourche complete - 1

Standard oil level: 145 ~ 148 mm (5.71 ~ 5.83 in)

From top of fully stretched damper assembly.

YAMAHA YZ450F-2007 - Fourche complete - 2

YAMAHA YZ450F-2007 - Fourche complete - 3

YAMAHA YZ450F-2007 - Fourche complete - 4

YAMAHA YZ450F-2007 - Fourche complete - 5

  1. Tighten:

  2. Locknut ①

NOTE:

Fully finger tighten the locknut onto the damper assembly.

  1. Loosen:

  2. Compression damping adjuster ①

NOTE:

  • Loosen the compression damping adjuster finger tight.

  • Record the set position of the adjuster (the amount of turning out the fully turned in position).

  • Install:

  • Base valve ①

To damper assembly ②.

NOTE:

First bring the damper rod pressure to a maximum. Then install the base valve while releasing the damper rod pressure.

  1. Check that the damper assembly is fully stretched.

Not fully stretched Repeat the steps 2 to 8.

YAMAHA YZ450F-2007 - Fourche complete - 6

YAMAHA YZ450F-2007 - Fourche complete - 7

YAMAHA YZ450F-2007 - Fourche complete - 8

YAMAHA YZ450F-2007 - Fourche complete - 9

  1. Tighten:

  2. Base valve ①

29 Nm (2.9 m·kg, 21 ft·lb)

NOTE:

Hold the damper assembly with the cap bolt ring wrench ② and use the cap bolt wrench ③ to tighten the base valve with specified torque.

YAMAHA YZ450F-2007 - NOTE: - 1

Cap bolt wrench: YM-01500/90890-01500

Cap bolt ring wrench: YM-01501/90890-01501

  1. After filling, pump the damper assembly ① slowly up and down more than 10 times to distribute the fork oil.
  2. While protecting the damper assembly ① with a rag and compressing fully, allow excessive oil to overflow on the base valve side.

CAUTION:

Take care not to damage the damper assembly.

  • Damper assembly smooth movement Tightness/binding/rough spots Repeat the steps 2 to 13.

15. Install:

  • Dust seal ①
  • Stopper ring ②
  • Oil seal ③ New
  • Oil seal washer ④
  • Slide metal ⑤ New To inner tube ⑥.

NOTE:

  • Apply the fork oil on the inner tube.
  • When installing the oil seal, use vinyl seat ⑧ 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 the oil seal washer with its projections ⑥ facing upward.

16. Install:

  • Piston metal ①

New

NOTE:

Install the piston metal onto the slot on inner tube.

17. Install:

  • Outer tube ①

To inner tube ②.

  • Slide metal ①
  • Oil seal washer ②

To outer tube slot.

NOTE:

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

YAMAHA YZ450F-2007 - Install: - 1

  1. Install:

  2. Oil seal ①

NOTE:

Press the oil seal into the outer tube with fork seal driver ②.

YAMAHA YZ450F-2007 - Install: - 2

  1. Install:

  2. Stopper ring ①

NOTE:

Fit the stopper ring correctly in the groove in the outer tube.

21.Install:

  • Dust seal ①

NOTE:

Apply the lithium soap base grease on the inner tube.

  1. Check:

  2. Inner tube smooth movement

Tightness/binding/rough spots Repeat the steps 15 to 21.

  1. Measure:

  2. Distance @

Out of specification Turn into the locknut.

YAMAHA YZ450F-2007 - Install: - 3

Distance @:

19 mm (0.75 in) or more

Between the damper assembly

① bottom and locknut ②

bottom.

  1. Install:

  2. Collar ①

  3. Fork spring ②

To damper assembly ③.

NOTE:

Install the collar with its larger dia. end ⑧ facing the fork spring.

  1. Install:

  2. Damper assembly ①

To inner tube ②.

CAUTION:

To install the damper assembly into the inner tube, hold the inner tube aslant. If the inner tube is held vertically, the damper assembly may fall into it, damaging the valve inside.

  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).

  • Controller:

  • Mouvement régulier du tube plongeur Raideur/coincement/rugosités Répéter les étapes 15 à 21.

  • Kontrollieren:

  • Leichtgangigkeit des Gleitrohrs Schwergängig/fest/stockend Schritte 15-21 wiederholen.

  • Mesurer:

  • Distance @

  • While compressing the inner tube ⑤, set the cap bolt ring wrench ⑦ between the inner tube and locknut ⑥.
  • Fully finger tighten the adjuster onto the damper assembly.

YAMAHA YZ450F-2007 - NOTE: - 1

Cap bolt ring wrench: YM-01501/90890-01501

YAMAHA YZ450F-2007 - NOTE: - 2

  1. Inspect:

  2. Gap @ between the adjuster ① and locknut ②.

Out of specification Retighten and readjust the locknut.

YAMAHA YZ450F-2007 - NOTE: - 3

Gap ⑧ between the adjuster and locknut: 0.5 1.0 ~mm (0.02 0.04 in)

NOTE:

If the adjuster is installed out of specification, proper damping force cannot be obtained.

YAMAHA YZ450F-2007 - NOTE: - 4

  1. Tighten:

  2. Adjuster (locknut) ①

29Nm (2.9 m·kg, 21 ft·lb)

NOTE: Hold the locknut ② and tighten the adjuster with specified torque.

27. Monter:

  1. Fill:

  2. Front fork oil ①

From outer tube top.

YAMAHA YZ450F-2007 - Monter: - 1

Recommended oil:

Suspension oil "S1"

Standard oil amount:

340~cm^3 (12.0 Imp oz, 11.5 US oz)

*350 cm³ (12.3 Imp oz, 11.8 US oz)

Extent of adjustment:

300 380~cm^3

(10.6 ~ 13.4 Imp oz,

10.1 ~ 12.8 US oz)

  • For EUROPE

YAMAHA YZ450F-2007 - Monter: - 2

ARNING

Never fail to make the oil amount adjustment between the maximum and minimum amount and always adjust each front fork to the same setting. Uneven adjustment can cause poor handling and loss of stability.

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 YZ450F-2007 - CAUTION: - 1

  1. Install:

  2. Damper assembly ①

To outer tube.

NOTE:

Temporarily tighten the damper assembly.

30. Monter:

NOTE: Install the protector guide with its wider side ⑧ facing downward.

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:

  • Damper assembly ①

30 Nm (3.0 m·kg, 22 ft·lb)

NOTE: Use the cap bolt ring wrench ② to tighten the damper assembly with specified torque.

YAMAHA YZ450F-2007 - Installation - 1

Cap bolt ring wrench: YM-01501/90890-01501

YAMAHA YZ450F-2007 - Installation - 2

  1. Adjust:

  2. Front fork top end ⑧

YAMAHA YZ450F-2007 - Installation - 3

Front fork top end (standard) @: Zero mm (Zero in)

  1. Monter:

  2. Guide de protection ①

N.B.:

  • Pinch bolt (under bracket) ②

21 Nm (2.1 m·kg, 15 ft·lb)

CAUTION:

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

YAMAHA YZ450F-2007 - CAUTION: - 1

YAMAHA YZ450F-2007 - CAUTION: - 2

YAMAHA YZ450F-2007 - CAUTION: - 3

  1. Install:

  2. Protector ①

  3. Bolt (protector) ②

7Nm (0.7m·kg, 5.1 ft·lb)

  1. Adjust:

  2. Rebound damping force

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

  1. Adjust:

  2. Compression damping force

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

YAMAHA YZ450F-2007 - CAUTION: - 4
Extent of removal:
① Handlebar removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalHANDLEBAR REMOVAL Number plateRemove the band only.
11Hot starter cable1Disconnect at the lever side.
2Hot starter lever holder1
3Clutch cable1Disconnect at the lever side.
4Clutch lever holder1
5"ENGINE STOP" button1
6Master cylinder1Refer to "REMOVAL POINTS".
7Throttle cable cap1
8Throttle cable #1 (pulled)1Disconnect at the throttle side.
9Throttle cable #2 (pushed)1Disconnect at the throttle side.
10Grip (right)1Refer to "REMOVAL POINTS".
11Tube guide1
12Collar1Refer to "REMOVAL POINTS".
13Grip (left)1
14Handlebar holder (upper)2
15Handlebar1
16Handlebar holder (lower)2

GUIDON

  1. Remove:

  2. Master cylinder bracket ①

  3. 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:

  2. 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

Handlebar

  1. Install:

  2. Handlebar holder (lower) ①

  3. Plain washer ②
  4. Nut [handlebar holder (lower)] ③

NOTE:

  • Install the handlebar holder (lower) with its side having the greater distance ⑧ from the mounting bolt center facing forward.
  • Apply the lithium soap base grease on the thread of the handlebar holder (lower).
  • Installing the handlebar holder (lower) in the reverse direction allows the front-to-rear offset amount of the handlebar position to be changed.
  • Do not tighten the nut yet.

POINTS DE DEPOSE

Maitre-cylindre

  • Handlebar ①
  • Handlebar holder (upper) ②
  • Bolt [handlebar holder (upper)] ③
  • The handlebar holder (upper) should be installed with the punched mark ⑧ forward.
  • Install the handlebar so that the marks ⑥ are in place on both sides.
  • Install the handlebar so that the projection © of the handlebar holder (upper) is positioned at the mark on the handlebar as shown.
  • First tighten the bolts on the front side of the handlebar holder (upper), and then tighten the bolts on the rear side.

3. Tighten:

  • Nut [handlebar holder (lower)] ①

34 Nm (3.4 m·kg, 24 ft·lb)

2. Monter:

34Nm(3,4m·kg,24ft·lb)

YAMAHA YZ450F-2007 - Monter: - 1

YAMAHA YZ450F-2007 - Monter: - 2

YAMAHA YZ450F-2007 - Monter: - 3

YAMAHA YZ450F-2007 - Monter: - 4

YAMAHA YZ450F-2007 - Monter: - 5

  1. Install:

  2. Grip (left) ①

Apply the adhesive to the handlebar ②.

NOTE:

  • Before applying the adhesive, wipe off grease or oil on the handlebar surface @ with a lacquer thinner.
  • Install the grip (left) to the handlebar so that the line ⑥ between the two arrow marks faces straight upward.

  • 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 @ 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.

  • Install:

  • Collar ①

  • Cover (grip cap) ②
  • Throttle grip ③

NOTE:

Apply the lithium soap base grease on the throttle grip sliding surface.

  1. Install:

  2. Throttle cables ①

To tube guide ②.

NOTE:

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

  1. Install:

  2. Throttle cable cap ①

  3. Screw (throttle cable cap) ②

4 Nm (0.4 m·kg, 2.9 ft·lb)

WARNING

After tightening the screws, check that the throttle grip ③ moves smoothly. If it does not, retighten the bolts for adjustment.

YAMAHA YZ450F-2007 - WARNING - 1

YAMAHA YZ450F-2007 - WARNING - 2

YAMAHA YZ450F-2007 - WARNING - 3

  1. Install:

  2. Cover (grip cap) ①

  3. Cover (throttle cable cap) ②

  4. Install:

  5. Master cylinder ①

  6. Master cylinder bracket ②
  7. Bolt (master cylinder bracket) ③

9Nm (0.9m· kg,6.5ft· lb)

NOTE:

Install the bracket so that the arrow mark ⑧ faces upward.
- First tighten the bolt on the upper side of the master cylinder bracket, and then tighten the bolt on the lower side.

  • 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 lever holder.

12. Install:

  • Clutch cable ①
    Hot starter cable ②

NOTE:

Apply the lithium soap base grease on the clutch cable end and hot starter cable end.

13. Adjust:

  • Clutch lever free play Refer to "CLUTCH ADJUSTMENT" section in the CHAPTER 3.
  • Hot starter lever free play Refer to “HOT STARTER LEVER ADJUSTMENT” section in the CHAPTER 3.

11. Monter:

YAMAHA YZ450F-2007 - Monter: - 1
Extent of removal:
① Under bracket removal
② Bearing removal

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalSTEERING REMOVALHold the machine by placing the suitable stand under the engine.Number plateHandlebarFront fenderWARNINGSupport the machine securely so there is no danger of it falling over.Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4.Refer to “HANDLEBAR” section.
123456789123456789Steering shaft nutFront forkHandle crownRing nutUnder bracketBearing race coverBearing (upper)Bearing (lower)Bearing race12111112Refer to “FRONT FORK” section.Use special tool.Refer to “REMOVAL POINTS”.Refer to “REMOVAL POINTS”.- Refer to “REMOVAL POINTS”.

DIRECTION

Ring nut wrench: YU-33975/90890-01403

WARNING

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

YAMAHA YZ450F-2007 - WARNING - 1

EC563300

Bearing (lower)

  1. Remove:

  2. Bearing (lower) ①

Use the floor chisel ②.

CAUTION:

Take care not to damage the steering shaft thread.

YAMAHA YZ450F-2007 - CAUTION: - 1

Bearing race

  1. Remove:

  2. Bearing race ①

Remove the bearing race using long rod

② and the hammer.

YAMAHA YZ450F-2007 - Bearing race - 1

EC564000

INSPECTION

EC564200

Steering shaft

  1. Inspect:

  2. Steering shaft ①

Bend/damage Replace.

POINTS DE DEPOSE

Ecrou de direction

  1. Déposer:

  2. Ecrou de direction ①

Hakenschlüssel: YU-33975/90890-01403

YAMAHA YZ450F-2007 - Ecrou de direction - 1

WARNING

Bearing and bearing race

  1. Wash the bearings and bearing races with a solvent.

  2. Inspect:

  3. Bearing ①

  4. Bearing race

Pitting/damage Replace bearings and bearing races as a set.

Install the bearing in the bearing races. Spin the bearings by hand. If the bearings hang up or are not smooth in their operation in the bearing races, replace bearings and bearing races as a set.

YAMAHA YZ450F-2007 - Bearing and bearing race - 1

YAMAHA YZ450F-2007 - Bearing and bearing race - 2

YAMAHA YZ450F-2007 - Bearing and bearing race - 3

EC565000

ASSEMBLY AND INSTALLATION

Under bracket

  1. Install:

  2. Bearing (lower) ①

NOTE:

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

  1. Install:

  2. Bearing race

  3. Bearing (upper) ①
  4. Bearing race cover ②

NOTE:

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

  1. Install:

  2. Under bracket ①

NOTE:

Apply the lithium soap base grease on the bearing, the portion ④ and thread 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:

  3. Plain washer ①

  4. Install:

  5. Front fork ①

  6. 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

145 Nm (14.5 m·kg, 105 ft·lb)

  1. Monter:

  2. Ecrou de direction ①

7Nm (0,7m· kg,5,1 ft·lb)

  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 YZ450F-2007 - Under bracket - 1

Front fork top end (standard) @: Zero mm (Zero in)

  1. Tighten:

  2. Pinch bolt (handle crown) ①

21Nm(2.1m·kg,15ft·lb)

  • Pinch bolt (under bracket) ②

21Nm(2.1m·kg,15ft·lb)

CAUTION:

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

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalSWINGARM REMOVALHold the machine by placing the suitable stand under the engine.Brake hose holderRear caliperBolt (brake pedal)Drive chainWARNINGSupport the machine securely so there is no danger of it falling over.Refer to “FRONT BRAKE AND REAR BRAKE” section.Shift the brake pedal backward.
1123456Chain supportChain tensioner (lower)Bolt (rear shock absorber-relay arm)Bolt (connecting rod)Pivot shaftSwingarm111111

BRAS OSCILLANT

Extent of removal:
YAMAHA YZ450F-2007 - BRAS OSCILLANT - 1
① Swingarm disassembly
③ Relay arm removal and disassembly

② Connecting rod removal and disassembly

Extent of removalOrderPart nameQ'tyRemarks
SWINGARM DISASSEMBLYRefer to “REMOVAL POINTS”.
2
1
1
2
2
2
2
8
10Refer to “REMOVAL POINTS”.

DEMONTAGE DU BRAS OSCILLANT

  1. Remove:

  2. Cap (left) ①

NOTE:

Remove with a slotted-head screwdriver inserted under the mark @ on the cap (left).

EC573200

Bearing

  1. Remove:

  2. Bearing ①

NOTE:

Remove the bearing by pressing its outer race.

EC574010

INSPECTION

Wash the bearings, bushes and collars in a solvent.

EC574111

Swingarm

  1. Inspect:

  2. Bearing ①

  3. Bush ②

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

  1. Inspect:

  2. Oil seal ③

Damage Replace.

Relay arm

  1. Inspect:

  2. Bearing ①

  3. Collar ②

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

  1. Inspect:

  2. Oil seal ③

Damage Replace.

POINTS DE DEPOSE

Capuchon

  1. Inspect:

  2. Bearing ①

  3. Collar ② Free play exists/unsmooth revolution/rust Replace bearing and collar as a set.

  4. Inspect:

  5. Oil seal ③ Damage Replace.

EC575000 ASSEMBLY AND INSTALLATION Bearing and oil seal

  1. Install:

  2. Bearing ①

  3. Oil seal ② To swingarm.

NOTE:

  • Apply the molybdenum disulfide grease on the bearing when installing.
  • Install the bearing by pressing it on the side having the manufacture's marks or numbers.
  • First install the outer and then the inner bearings to a specified depth from inside.

YAMAHA YZ450F-2007 - NOTE: - 1

Installed depth of bearings: Outer a: Zero mm (Zero in) Inner b: 6.5 mm (0.26 in)

  1. Install:

  2. Bearing ①

  3. Plain washer ②
  4. Oil seal ③ 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.
  • Apply the molybdenum disulfide grease on the plain washer.

YAMAHA YZ450F-2007 - NOTE: - 1

Installed depth of bearings @: Zero mm (Zero in)

Bielle

  1. Install:

  2. Bearing ①

  3. Oil seal ②

To connecting rod.

NOTE:

  • Apply the molybdenum disulfide grease on the bearing when installing.
  • Install the bearing by pressing it on the side having the manufacture's marks or numbers.

YAMAHA YZ450F-2007 - NOTE: - 1

Installed depth of bearings ④ : Zero mm (Zero in)

YAMAHA YZ450F-2007 - NOTE: - 2

Swingarm

  1. Install:

  2. Bush ①

  3. Thrust bearing ②
  4. Oil seal ③
    Collar ④

To swingarm ⑤.

NOTE:

Apply the molybdenum disulfide grease on the bushes, thrust bearings, oil seal lips and contact surfaces of the collar and thrust bearing.

YAMAHA YZ450F-2007 - NOTE: - 1

  1. Install:

  2. Collar ①

  3. Washer ②

To relay arm ③.

NOTE:

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

To connecting rod ②.

NOTE:

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

  1. Install:

  2. Connecting rod ①

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

YAMAHA YZ450F-2007 - NOTE: - 1

80Nm(8.0m·kg,58ft·lb)

To relay arm ⑤.

NOTE:

Apply the molybdenum disulfide grease on the bolt.

  1. Install:

Relay arm ①
- Bolt(relayarm) ②
- Plain washer ③
- Nut (relay arm) ④

To swingarm.

NOTE:

  • Apply the molybdenum disulfide grease on the bolt circumference and threaded portion.
  • Do not tighten the nut yet.

  • Install:

  • Swingarm ①

  • Pivot shaft ②

YAMAHA YZ450F-2007 - NOTE: - 2

85 Nm (8.5 m·kg, 61 ft·lb)

NOTE:

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

  • 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.

  • Monter:

  • Entretoise épaulée ① Sur la bielle ②.

N.B.:

80 Nm (8,0 m·kg, 58 ft·lb)

(am Umlenkhebel ⑤)

HINWEIS:

  • 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.

9. Install:

  • Bolt (rear shock absorber-relay arm) ①
  • Nut (rear shock absorber-relay arm) ②

53 Nm (5.3 m·kg, 38 ft·lb)

NOTE:

Apply the molybdenum disulfide grease on the bolt.

10. Tighten:

  • Nut (connecting rod) ①

80Nm(8.0m·kg,58ft·lb)

11. Tighten:

  • Nut (relay arm) ①

70 Nm (7.0 m · kg, 50 ft · lb)

12. Install:

  • Cap ①

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

  1. Monter:

  2. Boulon (bielle) ①
    Rondelle pleine ②

  3. Ecrou (bielle) ③

N.B.:

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

16 Nm (1.6 m·kg, 11 ft·lb)

14. Install:

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

7Nm(0.7m·kg,5.1ft·lb)

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

⑤ 7Nm(0.7m·kg,5.1ft·lb)

13. Monter:

YAMAHA YZ450F-2007 - Monter: - 1
Extent of removal:
① Rear shock absorber removal
② Rear shock absorber disassembly

Extent of removalOrderPart nameQ'tyRemarks
Preparation for removalREAR SHOCK ABSORBER REMOVAL Hold the machine by placing the suitable stand under the engine. Seat SilencerWARNING Support the machine securely so there is no danger of it falling over. Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4. Refer to “EXHAUST PIPE AND SILENCER” section in the CHAPTER 4.
11Clamp (air filter joint)1Only loosening.
2Rear frame1
3Bolt (rear shock absorber-relay arm)1Hold the swingarm.
4Bolt (rear shock absorber-frame)1
5Rear shock absorber1
6Locknut1Only loosening.
7Adjuster1Only loosening.
8Spring seat2

AMORTISSEUR ARRIERE

Extent of removalOrderPart nameQ'tyRemarks
9Spring guide (lower)1
10Spring guide (upper)1
11Spring (rear shock absorber)1
12Bearing2Refer to “REMOVAL POINTS”.

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 YZ450F-2007 - 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.

YAMAHA YZ450F-2007 - NOTES ON DISPOSAL (YAMAHA DEALERS ONLY) - 1

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 (upper bearing) ①

NOTE:

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

  1. Remove:

  2. Upper bearing ①

NOTE:

Remove the bearing by pressing its outer race.

  1. Remove:

  2. Lower bearing ①

NOTE:

Remove the bearing by pressing its outer race.

EC584000

INSPECTION

Rear shock absorber

  1. Inspect:

  2. Damper rod ①

Bends/damage Replace 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.

  • Spring seat ⑤

Cracks/damage Replace.

  • Bearing ⑥

Free play exists/unsmooth revolution/rust Replace.

POINTS DE DEPOSE

Roulement

ASSEMBLY AND INSTALLATION

EC585300

Bearing

  1. Install:

  2. Upper bearing ①

NOTE: Install the bearing parallel until the stopper ring groove appears by pressing its outer race.

CAUTION:

Do not apply the grease on the bearing outer race because it will wear the rear shock absorber surface on which the bearing is press fitted.

YAMAHA YZ450F-2007 - CAUTION: - 1

YAMAHA YZ450F-2007 - CAUTION: - 2

YAMAHA YZ450F-2007 - CAUTION: - 3

  1. Install:

  2. Stopper ring (upper bearing) ①

New

NOTE:

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

  1. Install:

  2. Lower bearing ①

NOTE:

Install the bearing by pressing it on the side having the manufacture's marks or numbers.

YAMAHA YZ450F-2007 - CAUTION: - 4

Installed depth of the bearing ④ : 4 mm (0.16 in)

EC585111

Spring (rear shock absorber)

  1. Install:

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

ASSEMBLAGE ET MONTAGE

Roulement

NOTE: Install the spring seat with the projection ⑧ brought into contact with the spring end, as shown.

  1. Tighten:

  2. Adjuster ①

  3. Adjust:

  4. Spring length (installed)

Refer to "REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT" section in the CHAPTER 3.

YAMAHA YZ450F-2007 - Roulement - 1

YAMAHA YZ450F-2007 - Roulement - 2

  1. Tighten:

  2. Locknut ①

Rear shock absorber

  1. Install:

  2. Dust seal ①

  3. O-ring ②
    New
    Collar ③

NOTE:

  • Apply the molybdenum disulfide grease on the dust seal lips and collars.
  • Apply the lithium soap base grease on the O-rings.

  • Monter:

  • Siège de ressort ①

N.B.:

  • Bush ①
  • Collar ②
  • Dust seal ③

NOTE:

  • Apply the molybdenum disulfide grease on the bearing and dust seal lips.
  • Install the dust seals with their lips facing outward.

3. Install:

Rear shock absorber

4. Install:

  • Bolt (rear shock absorber-frame) ①
  • Plain washer ②
  • Nut (rear shock absorber-frame) ③

56 Nm (5.6 m·kg, 40 ft·lb)

NOTE:

Apply the molybdenum disulfide grease on the bolt.

5. Install:

  • Bolt (rear shock absorber-relay arm) ①
  • Nut (rear shock absorber-relay arm) ②

53 Nm (5.3 m · kg, 38 ft · lb)

NOTE:

Apply the molybdenum disulfide grease on the bolt.

6. Install:

  • Rear frame ①
  • Bolt (rear frame) ②

32 Nm (3.2 m · kg, 23 ft · lb)

7. Tighten:

  • Bolt (air filter joint) ①

3 Nm (0.3 m · kg, 2.2 ft · lb)

A map-controlled, CDI ignition system is used in the YZ450F.

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 YZ450F-2007 - Tighten: - 1

Function of Component

ComponentFunction
TPS(throttle position sensor)Detects throttle valve opening and inputs it into the computer in the CDI unit as a throttle opening signal.
Pickup coilDetects signal rotor revolutions and inputs them into the computer in the CDI unit as engine revolution signals.
CDI unitThe signals of the 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 YZ450F-2007 - Principal of 3-Dimensional Control - 1
3-D Image Map of Ignition Timing (different from actual characteristics)

BOITIER CDI COMMANDE PAR PRESSION ABSOLUE DE LA TUBULURE D'ADMISSION

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 YZ450F-2007 - BOITIER CDI COMMANDE PAR PRESSION ABSOLUE DE LA TUBULURE D'ADMISSION - 1
*marked: Only when the ignition checker is used.

NOTE:

  • Remove the following parts before inspection.
    1) Seat
    2) Fuel tank
  • Use the following special tools in this inspection.

YAMAHA YZ450F-2007 - NOTE: - 1
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754

YAMAHA YZ450F-2007 - NOTE: - 2
Pocket tester: YU-3112-C/90890-03112

SYSTEME D'ALLUMAGE

ETAPES DU CONTROLE

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

  4. Ignition coil ③

  5. 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 YZ450F-2007 - ETAPES DU CONTROLE - 1

Minimum spark gap: 6.0 mm (0.24 in)

COUPLERS, LEADS AND IGNITION COIL CONNECTION INSPECTION

  1. Check:

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

  3. Ignition coil and spark plug as they are fitted Push in the ignition coil until it closely contacts the spark plug hole in the cylinder head cover.

EC625001

"ENGINE STOP" BUTTON INSPECTION

  1. Inspect:

  2. "ENGINE STOP" button conduct

Tester (+) lead → Black/White lead ① Tester (-) lead → Black lead ②
0B/W ①B ②Tester selec- tor position
PUSH IN○—○Ω×1
FREE

No continuity while being pushed Replace.

Continuity while being freed Replace.

TEST DE LA LONGUEUR D'ETINCELLE

IGNITION COIL INSPECTION

  1. Remove the ignition coil cap.
  2. Inspect:

Primary coil resistance

Out of specification Replace.

Tester (+) lead → Orange lead ① Tester (-) lead → Black lead ②
Primary coil resistanceTester selector position
0.08 ~ 0.10 Ω at 20 °C (68 °F)Ω × 1

YAMAHA YZ450F-2007 - IGNITION COIL INSPECTION - 1

YAMAHA YZ450F-2007 - IGNITION COIL INSPECTION - 2

YAMAHA YZ450F-2007 - IGNITION COIL INSPECTION - 3

  1. Inspect:

  2. Secondary coil resistance

Out of specification Replace.

Tester (+) lead → Orange lead ① Tester (-) lead → Spark plug terminal ②
Secondary coil resistanceTester selector position
4.6 ~ 6.8 kΩ at 20 °C (68 °F)kΩ × 1
  1. Inspect:

  2. Sealed portion of ignition coil @

  3. Spark plug terminal pin ⑥
  4. Threaded portion of spark plug ©

Wear Replace.

EC62701:

CDI MAGNETO INSPECTION

  1. Inspect:

Pick-up coil resistance

Out of specification Replace.

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
720 ~ 1,080 Ω at 20 °C (68 °F)Ω × 100

3. Inspect:

Source coil 2 resistance

Out of specification Replace.

Tester (+) lead → Pink lead ① Tester (-) lead → Black lead ②
Source coil 2 resistanceTester selector position
44 ~ 66 Ω at 20 °C (68 °F)Ω × 10

YAMAHA YZ450F-2007 - Inspect: - 1

NEUTRAL SWITCH INSPECTION

1. Inspect:

  • Neutral switch conduct
Tester (+) lead → Sky blue lead ① Tester (-) lead → Ground ②
Sb ①Ground ②Tester selec- tor position
NEUTRAL○-○Ω×1
IN GEAR

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.

SYSTEME D'ALLUMAGE ZUNDSYSTEM

YAMAHA YZ450F-2007 - SYSTEME D'ALLUMAGE ZUNDSYSTEM - 1

2. Controller:

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

YAMAHA YZ450F-2007 - Controller: - 1

*marked: Refer to "IGNITION SYSTEM" section.

NOTE:

Use the following special tools in this inspection.

YAMAHA YZ450F-2007 - NOTE: - 1

Pocket tester: YU-3112-C/90890-03112

SYSTEME TPS (CAPTEUR DE POSITION DE PAPILLON DES GAZ)

ETAPES DU CONTROL

Do not loosen the screw {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.

EC624000

COUPLERS AND LEADS CONNECTION INSPECTION

  1. Check:

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

YAMAHA YZ450F-2007 - COUPLERS AND LEADS CONNECTION INSPECTION - 1

YAMAHA YZ450F-2007 - COUPLERS AND LEADS CONNECTION INSPECTION - 2

TPS COIL INSPECTION

  1. Inspect:

  2. 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 ①

NOTE:

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

REMARQUES CONCERNANT LA MANIPULATION

ATTENTION:

  1. Inspect:

  2. 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)

YAMAHA YZ450F-2007 - ATTENTION: - 1

YAMAHA YZ450F-2007 - ATTENTION: - 2

TPS REPLACEMENT AND ADJUSTMENT

  1. Remove:

  2. TPS coupler

  3. Carburetor

  4. Remove:

  5. Screw (TPS) ①

  6. TPS ②

NOTE:

Loosen the screw (TPS) using the T25 bit.

  1. Replace:

TPS

  1. Install:

  2. TPS ①

  3. Screw (TPS) ②

NOTE:

  • Align the slot ⑧ in the TPS with the projection ⑥ on the carburetor.
  • Temporarily tighten the screw (TPS).

  • Install:

  • Carburetor
    TPS coupler

3. Controller:

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

YAMAHA YZ450F-2007 - Controller: - 1

  1. Insert the thin electric conductors (2) (lead) into the TPS coupler (1), as shown, and connect the tester to them.

Tester (+) lead Yellow lead ③ Tester (-) lead Black lead ④

CAUTION:

  • Do not insert the electric conductors more than required because it may reduce the waterproof function of the coupler.
  • Make sure that a short-circuit does not develop between the terminals because it may cause damage to electrical components.

  • Start the engine.

  • Adjust:

TPS output voltage

YAMAHA YZ450F-2007 - CAUTION: - 1

Adjustment steps:

Adjust the installation angle of the TPS ① to obtain the specified output voltage.

NOTE:

Measure the output voltage accurately with a digital electronic voltmeter that gives an easy reading of a small voltage.

TPS output voltageTester selector position
0.58 ~ 0.78 VDCV
  1. Régler:

  2. Ralenti

Se reporter à la section “REGLAGE DU REGIME DE RALENTI” au CHAPITRE 3.

  1. Put the aligning marks @ on the TPS and carburetor.
  2. Stop the engine.
  3. Remove the carburetor.

  4. Tighten:

  5. Screw (TPS) ①

NOTE: Tighten the screw (TPS) using the T25 bit.

  1. Install the carburetor.

EC694000

TPS INPUT VOLTAGE INSPECTION

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

  4. TPS input voltage

Out of specification Replace the CDI unit.

Tester (+) lead → Blue lead ① Tester (-) lead → Black/Blue lead ②
TPS input voltageTester selector position
4 ~ 6 VDCV-20
  • 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 YZ450F-2007 - 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.

MISE AU POINT MOTEUR

  • The carburetor is extremely sensitive to foreign matter (dirt, sand, water, etc.). During installation, do not allow foreign matter to get into the carburetor.
  • Always handle the carburetor and its components carefully. Even slight scratches, bends or damage to carburetor parts may prevent the carburetor from functioning correctly. Carefully perform all servicing with the appropriate tools and without applying excessive force.
  • When the engine is stopped or when riding at no load, do not open and close the throttle unnecessarily. Otherwise, too much fuel may be discharged, starting may become difficult or the engine may not run well.
  • After installing the carburetor, check that the throttle operates correctly and opens and closes smoothly.

Atmospheric conditions and carburetor settings

Air temp.HumidityAir pressure (altitude)MixtureSetting
HighHighLow (high)RicherLeaner
LowLowHigh (low)LeanerRicher

The air density (i.e., concentration of oxygen in the air) determines the richness or leanness of the air/fuel mixture. Therefore, refer to the above table for mixture settings.

That is:

  • Higher temperature expands the air with its resultant reduced density.
  • Higher humidity reduces the amount of oxygen in the air by so much of the water vapor in the same air.
  • Lower atmospheric pressure (at a high altitude) reduces the density of the air.

ATTENTION:

Effects of the setting parts on the throttle valve opening
YAMAHA YZ450F-2007 - ATTENTION: - 1
① Pilot screw/pilot jet
② Throttle valve cutaway
③ Jet needle
(4) Main jet

YAMAHA YZ450F-2007 - ATTENTION: - 2

Main system

The FLATCR carburetor has a primary main jet. This type of main jet is perfect for racing machines since it supplies an even flow of fuel, even at full load. Use the main jet and the jet needle to set the carburetor.

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

The FLATCR carburetor is manufactured with a pilot screw. The pilot screw adjustment ranges from fully closed throttle to 1/4 open throttle.

YAMAHA YZ450F-2007 - Main system - 1

Main jet adjustment

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

Standard main jet#160

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 YZ450F-2007 - Main jet adjustment - 1
A Idle
Fully open

Système de ralenti

Pilot screw adjustment

The richness of the air-fuel mixture with the throttle fully closed to 1/4 open can be set by turning the pilot screw ① . Turning in the pilot screw will make the mixture lean at low speeds, and turning it out will enrich it.

Standard pilot screw position (example)1-1/4

NOTE:

  • If the idling speed fluctuates, turn the pilot screw only 1 / 2 of a turn in either direction.
  • To optimize the fuel flow at a smaller throttle opening, each machine's pilot screw has been individually set at the factory. Before adjusting the pilot screw, turn it in fully and count the number of turns. Record this number as the factory-set number of turns out.

YAMAHA YZ450F-2007 - NOTE: - 1
Effects of adjusting the pilot screw (reference)

A Idle
Fully open
① 1-3/4 turns out
(2) 3 / 4 turns out
(3) 1-1/4 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 ①.

Standard pilot jet#45

Effects of adjusting the pilot jet (reference)

YAMAHA YZ450F-2007 - Effects of adjusting the pilot jet (reference) - 1

A Idle B Fully open

YAMAHA YZ450F-2007 - Effects of adjusting the pilot jet (reference) - 2

Jet needle groove position adjustment

Adjusting the jet needle ① position affects the acceleration when the throttle is 1/8 to 3/4 open.

  1. Too rich at intermediate speeds

Rough engine operation is felt and the engine will not pick up speed smoothly. In this case, step up the jet needle clip by one groove and move down the needle to lean out the mixture.

  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.4 groove

Effects of changing the jet needle groove position (reference)

YAMAHA YZ450F-2007 - Effects of changing the jet needle groove position (reference) - 1

A Idle
Fully open
① No.5 groove
② No.3 groove
③ No.4 groove

Jet needle adjustment

The jet needle is adjusted by changing it.

Standard jet needleNFLR

The jet needle setting parts, having the same taper angle, are available in different straight portion diameters and in different taper starting positions.

YAMAHA YZ450F-2007 - Jet needle adjustment - 1

包 Reference needle
0.5 leaner

Changing from NFLR-4 to NFPR-4 has the same effect as a rising of 0.5 clip position.

Diameter of straight portion Clip positionRich← Lean
NPQRSTU
Rich Lean1 richerNFLN-5NFLP-5NFLQ-5NFLR-5NFLS-5NFLT-5NFLU-5
0.5 richerNFPN-4NFPP-4NFPQ-4NFPR-4NFPS-4NFPT-4NFPU-4
STDNFLN-4NFLP-4NFLQ-4NFLR-4NFLS-4NFLT-4NFLU-4
0.5 leanerNFPN-3NFPP-3NFPQ-3NFPR-3NFPS-3NFPT-3NFPU-3
1 leanerNFLN-3NFLP-3NFLQ-3NFLR-3NFLS-3NFLT-3NFLU-3

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 YZ450F-2007 - Effects of changing the jet needle (reference) - 1

A Idle

Fully open

Relationship with throttle opening

The flow of the fuel through the carburetor main system is controlled by the main jet and then, it is further regulated by the area between the main nozzle and the jet needle.

The fuel flow relates to the diameter of the straight portion of the jet needle with the throttle 1/8 to 1/4 open and relates to the clip position with the throttle 1/8 to 3/4 open.

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

YAMAHA YZ450F-2007 - Relationship with throttle opening - 1

Leak jet adjustment (accelerator pump adjustment)

The leak jet ① is a setting part that adjusts the flow of fuel discharged by the accelerator pump. Since the accelerator pump operates only when throttle is open, the leak jet is used to adjust a fuel mixture ratio for quick throttle opening and is therefore different from other setting parts that adjust a fuel mixture for each throttle opening (each engine speed).

  1. The engine breathes hard in quick throttle opening.

Select a leak jet having lower calibrating No. than standard to enrich the mixture.

#55 → #50

  1. Rough engine operation is felt in quick throttle opening.

Select a leak jet having higher calibrating No. than standard to lean out the mixture.

#55 → #60

Standard leak jet#55

Carburetor setting parts

Part nameSizePart number
Main jet Rich#1724MX-14943-92
#1704MX-14943-41
(STD)#1684MX-14943-91
#1654MX-14943-40
#1624MX-14943-90
#1604MX-14943-39
#1584MX-14943-89
#1554MX-14943-38
#1524MX-14943-88
#1504MX-14943-37
#1484MX-14943-87
Pilot jet Rich#524MX-14948-08
#504MX-14948-07
(STD)#484MX-14948-06
#454MX-14948-05
#424MX-14948-04
#404MX-14948-03
#384MX-14948-02
Jet needle RichNFPN5TA-14916-PN
NFPP5TA-14916-PP
NFPQ5TA-14916-P1
NFPR5TA-14916-PR
NFPS5TA-14916-PS
NFPT5TA-14916-PT
NFPU5TA-14916-PU
(STD)NFLN5TA-14916-LN
NFLP5TA-14916-LP
NFLQ5TA-14916-L1
NFLR5TA-14916-LR
NFLS5TA-14916-LS
NFLT5TA-14916-LT
NFLU5TA-14916-LU
Leak jet Rich#454JT-1494F-05
#504JT-1494F-07
(STD)#554JT-1494F-09
#604JT-1494F-11
#654JT-1494F-13

Examples of carburetor setting depending on symptom

SymptomSettingChecking
At full throttleHard breathingShearing noiseWhitish spark plug\(\downarrow\)Lean mixtureIncrease main jet calibration no.(Gradually)Discoloration of spark plug →If tan color, it is in good condition.If cannot be corrected:Clogged float valve seatClogged fuel hoseClogged fuel cockCheck that the accelerator pump operates smoothly.
At full throttleSpeed pick-up stopsSlow speed pick-upSlow responseSooty spark plug\(\downarrow\)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 mixtureLower jet needle clip position.(1 groove down)Groove 1Groove 2Groove 3Groove 4Groove 5Groove 6Grove 7JET needleClip(Standard)RicherLeaner↑(Standard)↓
Rich mixtureRaise jet needle clip position.(1 groove up)
1/4 ~ 3/4 throttleHard breathingLack of speedLower jet needle clip position.(1 groove down)
1/4 ~ 1/2 throttleSlow speed pick-upPoor accelerationRaise jet needle clip position.(1 groove up)The clip position is the jet needle groove on which the clip is installed.The positions are numbered from the top Check that the accelerator pump operates smoothly (except for rich mixture symptom).
Closed to 1/4 throttleHard breathingSpeed downUse jet needle with a smaller diameter.Slow-speed-circuit passageClogged → Clean.Overflow from carburetor
Closed to 1/4 throttlePoor accelerationUse jet needle with a larger diameterRaise jet needle clip position.(1 groove up)
Poor response in the low to intermediate speedsRaise jet needle clip position.If this has no effect, lower the jet needle clip position.
Poor response when throttle is opened quicklyCheck overall settings.Use main jet with a lower calibration no.Raise jet needle clip position.(1 groove up)If these have no effect, use a main jet with a higher calibration no. and lower the jet needle clip position.Check air cleaner for fouling.Check that the accelerator pump operates smoothly.
  • This should be taken simply for an example. It is necessary to set the carburetor while checking the operating conditions of the engine.

Selection of the secondary reduction ratio (Sprocket)

Secondary

reduction

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

ratio

$$ N u m b e r o f d r i v e s p r o c k e t t e e t h $$

Standard secondary reduction ratio

49/13 (3.769)

  • 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.

CHÂSSIS

Drive and driven sprockets setting parts

Part nameSizePart number
Drive sprocket ① (STD)13T9383E-13233
Driven sprocket ② (STD)47T1C3-25447-00
48T1C3-25448-00
49T1C3-25449-00
50T1C3-25450-00
51T1C3-25451-00
52T1C3-25452-00

EC721002

Tire pressure

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

YAMAHA YZ450F-2007 - Tire pressure - 1

Standard tire pressure: 100 kPa (1.0 kgf/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 YZ450F-2007 - Tire pressure - 2

Extent of adjustment: 60 80 kPa (0.6 0.8 ~kgf / 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 YZ450F-2007 - Tire pressure - 3

Extent of adjustment: 100 120 kPa (1.0 ~ 1.2 kgf/cm ^2 , 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 amount.

  3. Setting of spring preload

  4. Change the spring.

  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 amount and characteristics of fork oil

Damping characteristic near the final stroke can be changed by changing the fork oil amount.

CAUTION:

Adjust the oil amount in 5cm^3 (0.2 Imp oz, 0.2 US oz) increments or decrements. Too small oil amount 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 large oil amount will cause the air spring characteristics to have a tendency to be stiffer with the consequent deteriorated performance and characteristics. Therefore, adjust the front fork within the specified range.

YAMAHA YZ450F-2007 - CAUTION: - 1

Standard oil amount: 340~cm^3 (12.0 Imp oz, 11.5 US oz) *350 cm³ (12.3 Imp oz, 11.8 US oz)

Extent of adjustment: 300 380 ~cm^3 (10.6 ~ 13.4 Imp oz, 10.1 ~ 12.8 US oz)

  • For EUROPE
    A Air spring characteristics in relation to oil amount change
    Load
    Stroke
    ① Max. oil amount
    ② Standard oil amount
    ③ Min. oil amount

YAMAHA YZ450F-2007 - CAUTION: - 2

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.

  • Use of stiff spring

Generally a stiff spring gives a stiff riding feeling. Rebound damping tends to become weaker, resulting in lack of a sense of contact with the road surface or in a vibrating handlebar.

To set a stiff spring:

  • Change the rebound damping.
    Turn in one or two clicks.
  • Change the compression damping.
    Turn out one or two clicks.

Front fork setting parts

  • Front fork spring ①
TYPESPRING RATESPRING PART NUMBERI.D. MARK (slits)
SOFT0.3981C3-23141-A1I
0.4081C3-23141-B1II
0.4181C3-23141-C1III
0.4281C3-23141-D1III
0.4381C3-23141-E1III
0.4491C3-23141-F1I-I
0.4591C3-23141-G1I-II
STD0.4692S2-23141-L1-
STIFF0.4791C3-23141-J1I-III

NOTE:

The I.D. mark (slits) ⑧ is proved on the end of the spring.

EC72B000

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.
  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 ⑥ between the rear wheel axle center and the rear fender holding bolt.
  3. Loosen the locknut ① and make adjustment by turning the spring adjuster ② to achieve the standard figure from the subtraction of the length ⑥ from the length ⑧.

YAMAHA YZ450F-2007 - Rear suspension setting - 1

Standard figure: 90 100 ~mm (3.5 ~ 3.9 in)

NOTE:

  • If the machine is new and after it is broken in, the same set length of the spring may change because of the initial fatigue, etc. of the spring. Therefore, be sure to make re-evaluation.
  • If the standard figure cannot be achieved by adjusting the spring adjuster and changing the spring set length, replace the spring with an optional one and make re-adjustment.

Setting of spring after replacement

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

  1. Use of soft spring

  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.

CAUTION:

When using a rear cushion other than currently installed, use the one whose overall length ⑧ does not exceed the standard as it may result in faulty performance. Never use one whose overall length is greater than standard.

YAMAHA YZ450F-2007 - CAUTION: - 1

Length ⑧ of standard shock: 490 mm (19.29 in)

Rear shock absorber setting parts

  • Rear shock spring ①

[Equal-pitch titanium spring]

TYPESPRING RATESPRING PART NUMBERI.D. MARKSPRING FREE LENGTH (approx.)
SOFT4.51C3-22212-00Green265
4.71C3-22212-10Red265
4.91C3-22212-20Black265
5.11C3-22212-30Blue265
5.31C3-22212-40Yellow275
STD5.51C3-22212-50Pink275
STIFF5.71C3-22212-60White275

[Equal-pitch steel spring]

TYPESPRING RATESPRING PART NUMBERI.D. MARK/Q'TYSPRING FREE LENGTH
4.35UN-22212-00Brown/1260

[Unequal-pitch steel spring]

TYPESPRING RATE (approx.)SPRING PART NUMBERI.D. MARK/ Q'TYSPRING FREE LENGTH
SOFT4.55UN-22212-A0Green/2275
4.75UN-22212-B0Red/2275
4.95UN-22212-C0Black/2275
5.15UN-22212-D0Blue/2275
5.35UN-22212-E0Yellow/2275
5.55UN-22212-F0Pink/2275
STIFF5.75UN-22212-G0White/2275

CAUTION:

Install the spring seat ② to the titanium spring.

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 ⑧ is marked at the end of the spring.
  • Spring specification varies according to the color and quantity of I.D. marks.
  • Extent of adjustment (spring length)

[Titanium spring]

SPRING FREE LENGTHEXTENT OF ADJUSTMENT®
Approx. 265 mm (10.43 in)One I.D. mark 245.5 ~ 263.5 mm (9.67 ~ 10.37 in) Two I.D. marks 251.5 ~ 269.5 mm (9.90 ~ 10.61 in) Three I.D. marks 243.0 ~ 261.0 mm (9.57 ~ 10.28 in)
Approx. 275 mm (10.83 in)One I.D. mark 255.5 ~ 273.5 mm (10.06 ~ 10.77 in) Two I.D. marks 261.5 ~ 279.5 mm (10.30 ~ 11.00 in) Three I.D. marks 253.0 ~ 271.0 mm (9.96 ~ 10.67 in)

[Steel spring]

SPRING FREE LENGTHEXTENT OF ADJUSTMENT⑥
260 mm (10.24 in)240.5 ~ 258.5 mm (9.47 ~ 10.18 in)
275 mm (10.83 in)255.5 ~ 273.5 mm (10.06 ~ 10.77 in)
  • If any of the following symptoms is experienced with the standard position as the base, make resetting by reference to the adjustment procedure given in the same chart.
  • Before any change, set the rear shock absorber sunken length to the standard figure 90 100 ~mm (3.5 ~ 3.9 in).
SymptomSectionCheckAdjust
JumpLarge gapMedium gapSmall gap
Stiff over entire rangeCompression dampingTurn adjuster counterclockwise (about 2 clicks) to decrease damping.
Oil amountDecrease oil amount by about 5 ~ 10 cm3(0.2 ~ 0.4 Imp oz, 0.2 ~ 0.3 US oz).
SpringReplace with soft spring.
Unsmooth movement over entire rangeOuter tubeCheck for any bends, dents, and other noticeable scars, etc. If any, replace affected parts.
Inner tubeReplace with a new one for extended use.
Slide metalReplace with a new one for extended use.
Piston metalRettigen to specified torque.
Under bracket tightening torque
Poor initial movementRebound dampingTurn adjuster counterclockwise (about 2 clicks) to decrease damping.
Oil sealApply grease in oil seal wall.
Soft over entire range, bottoming outCompression dampingTurn adjuster clockwise (about 2 clicks) to increase damping.
Oil amountIncrease oil amount by about 5 ~ 10 cm3(0.2 ~ 0.4 Imp oz, 0.2 ~ 0.3 US oz).
SpringReplace with stiff spring.
Stiff toward stroke endOil amountDecrease oil amount by about 5 cm3(0.2 Imp oz, 0.2 US oz).
Soft toward stroke end, bottoming outOil amountIncrease oil amount by about 5 cm3(0.2 Imp oz, 0.2 US oz).
Stiff initial movementCompression dampingTurn adjuster counterclockwise (about 2 clicks) to decrease damping.
Low front, tending to lower front postureCompression dampingTurn adjuster clockwise (about 2 clicks) to increase damping.
Rebound dampingTurn adjuster counterclockwise (about 2 clicks) to decrease damping.
Balance with rear endSet sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when one passenger is astride seat (lower rear posture).
Oil amountIncrease oil amount by about 5 cm3(0.2 Imp oz, 0.2 US oz).
“Obtrusive” front, tending to upper front postureCompression dampingTurn adjuster counterclockwise (about 2 clicks) to decrease damping.
Balance with rear endSet sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in) when one passenger is astride seat (upper rear posture).
SpringReplace with soft spring.
Oil amountDecrease oil amount by about 5 ~ 10 cm3(0.2 ~ 0.4 Imp oz, 0.2 ~ 0.3 US oz).

Rear shock absorber

NOTE:

  • If any of the following symptoms is experienced with the standard position as the base, make resetting by reference to the adjustment procedure given in the same chart.
  • Adjust the rebound damping in 2-click increments or decrements.
  • Adjust the low compression damping in 1-click increments or decrements.
  • Adjust the high compression damping in 1/6 turn increments or decrements.
SymptomSectionCheckAdjust
JumpLarge gapMedium gapSmall gap
Stiff, tending to sinkRebound dampingSpring set lengthTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger is astride seat.
Spongy and unstableRebound dampingLow compression dampingSpringTurn adjuster clockwise (about 2 clicks) to increase damping.Turn adjuster clockwise (about 1 click) to increase damping.Replace with stiff spring.
Heavy and draggingRebound dampingSpringTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Replace with soft spring.
Poor road grippingRebound dampingLow compression dampingHigh compression dampingSpring set lengthSpringTurn adjuster counterclockwise (about 2 clicks) to decrease damping.Turn adjuster clockwise (about 1 clicks) to increase damping.Turn adjuster clockwise (about 1/6 clicks) to increase damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger is astride seat.Replace with soft spring.
Bottoming outHigh compression dampingSpring set lengthSpringTurn adjuster clockwise (about 1/6 turn) to increase damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger in astride seat.Replace with stiff spring.
BouncingRebound dampingSpringTurn adjuster clockwise (about 2 clicks) to increase damping.Replace with soft spring.
Stiff travelHigh compression dampingSpring set lengthSpringTurn adjuster counterclockwise (about 1/6 turn) to decrease damping.Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when one passenger is astride seat.Replace with soft spring.
Table of contents Click a title to access it
Manual assistant
Powered by Anthropic
Waiting for your message
Product information

Brand : YAMAHA

Model : YZ450F-2007

Category : Off-road motorcycle