Yamaha WR250F(W) Service Manual

20085UM-28199-71WR250F(X)20085UM-28199-71WR250F(X)WR250F(X)2008OWNER’S SERVICE MANUALMANUEL D’ATELIER DUPROPRIETAIRE

1-2MACHINE IDENTIFICATIONMACHINE IDENTIFICATIONThere are two significant reasons for knowing the serial number of your machine:1. When ordering parts,

5-6CARBURETOR19 Needle jet 120 Spacer 121 Pilot jet 122 Starter jet 123 Push rod 1 Pull the push rod.24 Throttle shaft assembly 125 Push rod link leve

5-7CARBURETORHANDLING NOTEDo not loosen the screw (throttle position sensor) "1" except when changing the throttle position sen-sor due to f

5-8CARBURETORCHECKING THE ACCELERATOR PUMP1. Inspect:• Diaphragm (accelerator pump) "1"• Spring (accelerator pump) "2"• Accelerato

5-9CARBURETOR9. Install:• Push rod "1"While holding down the lever 1 "2", in-sert the push rod farthest into the car-buretor. 10.

5-10CARBURETORa. Fully turn in the accelerator pump adjusting screw "3".b. Check that the link lever "4" has free play "b&quo

5-11AIR INDICTOIN SYSTEMAIR INDICTOIN SYSTEMREMOVING THE AIR INDUCTION SYSTEMOrder Part name Q'ty Remarks1 Bracket 12 Air cut-off valve assembly

5-12AIR INDICTOIN SYSTEMCHECKING THE AIR INDUCTION SYSTEM1. Inspect:• Air induction hoseCrack/damage→ Replace.• Air induction pipeCrack/damage → Repla

5-13CAMSHAFTSCAMSHAFTSREMOVING THE CYLINDER HEAD COVEROrder Part name Q'ty RemarksSeat and fuel tank Refer to "SEAT, FUEL TANK AND SIDE COVE

5-14CAMSHAFTSREMOVING THE CAMSHAFTSOrder Part name Q'ty Remarks1 Timing mark accessing screw 1 Refer to removal section.2 Crankshaft end accessin

5-15CAMSHAFTSREMOVING THE CAMSHAFT1. Remove:• Timing mark accessing screw "1"• Crankshaft end accessing screw "2"2. Align:• T.D.C.

1-3CHECKING OF CONNECTIONALL REPLACEMENT PARTS1. We recommend to use Yamaha genuine parts for all replace-ments. Use oil and/or grease rec-ommended by

5-16CAMSHAFTSMeasurement steps:a. Install the camshaft onto the cylin-der head.b. Position a strip of Plastigauge® "1" onto the camshaft.c.

5-17CAMSHAFTSThe camshafts should be installed onto the cylinder head so that the punch mark "c" on the exhaust cam-shaft and the punch mark

5-18CYLINDER HEADCYLINDER HEADREMOVING THE CYLINDER HEADOrder Part name Q'ty RemarksSeat and fuel tank Refer to "SEAT, FUEL TANK AND SIDE CO

5-19CYLINDER HEADCHECKING THE CYLINDER HEAD1. Eliminate:• Carbon deposits (from the com-bustion chambers)Use a rounded scraper.Do not use a sharp inst

5-20VALVES AND VALVE SPRINGSVALVES AND VALVE SPRINGSREMOVING THE VALVES AND VALVE SPRINGSOrder Part name Q'ty RemarksCylinder head Refer to "

5-21VALVES AND VALVE SPRINGSREMOVING THE VALVE LIFTER AND VALVE COTTER1. Remove:• Valve lifter "1"• Pad "2"Identify each lifter &

5-22VALVES AND VALVE SPRINGS• Margin thickness "a"Out of specification→ Replace.5. Measure:• Runout (valve stem)Out of specification → Repla

5-23VALVES AND VALVE SPRINGS2. Measure:• Compressed spring force "a"Out of specification→ Replace.b. Installed length3. Measure:• Spring til

5-24CYLINDER AND PISTONCYLINDER AND PISTONREMOVING THE CYLINDER AND PISTONOrder Part name Q'ty RemarksCylinder head Refer to "CYLINDER HEAD

5-25CYLINDER AND PISTONREMOVING THE PISTON AND PISTON RING1. Remove:• Piston pin clip "1"• Piston pin "2"• Piston "3"• P

1-4SPECIAL TOOLSSPECIAL TOOLSThe proper special tools are necessary for complete and accurate tune-up and assembly. Using the correct special tool wil

5-26CYLINDER AND PISTON3. Measure:• Ring end gapOut of specification→ Replace.You cannot measure the end gap on the expander spacer of the oil control

5-27CYLINDER AND PISTON3. Install:• Cylinder gasket "1" • Cylinder "2"Install the cylinder with one hand while compressing the pis

5-28CLUTCHCLUTCHREMOVING THE CLUTCHOrder Part name Q'ty RemarksDrain the engine oil. Refer to "CHANGING THE ENGINE OIL" section in the

5-29CLUTCH14 Nut (clutch boss) 1 Refer to removal section.15 Lock washer 1 Refer to removal section.16 Clutch boss 1 Refer to removal section.17 Thrus

5-30CLUTCHREMOVING THE CLUTCH BOSS1. Remove:• Nut "1"• Lock washer "2"• Clutch boss "3"Straighten the lock washer tab an

5-31CLUTCH2. Install:• Lock washer "1" • Nut (clutch boss) "2"Use the clutch holding tool "3" to hold the clutch boss.A.

5-32CLUTCHTighten the bolts in stage, using a crisscross pattern.

5-33OIL FILTER ELEMENT AND WATER PUMPOIL FILTER ELEMENT AND WATER PUMPREMOVING THE OIL FILTER ELEMENT AND WATER PUMPOrder Part name Q'ty RemarksD

5-34OIL FILTER ELEMENT AND WATER PUMP9 Washer 1 Refer to removal section.10 Impeller shaft 1 Refer to removal section.11 Oil seal 2 Refer to removal s

5-35OIL FILTER ELEMENT AND WATER PUMPREMOVING THE IMPELLER SHAFT1. Remove:• Impeller "1"• Washer "2"• Impeller shaft "3"

1-5SPECIAL TOOLSSteering nut wrenchYU-33975, 90890-01403 This tool is used when tighten the steering ring nut to specification.Damper rod holderYM-014

5-36OIL FILTER ELEMENT AND WATER PUMPINSTALLING THE RIGHT CRANKCASE COVER1. Install:• Dowel pin "1"• O-ring "2" • Collar "3&q

5-37BALANCERBALANCERREMOVING THE BALANCEROrder Part name Q'ty RemarksPrimary driven gear Refer to "CLUTCH" section.Right crankcase cov

5-38BALANCERREMOVING THE BALANCER1. Straighten the lock washer tab.2. Loosen:• Nut (primary drive gear) "1"• Nut (balancer shaft driven gear

5-39OIL PUMPOIL PUMPREMOVING THE OIL PUMPOrder Part name Q'ty RemarksPrimary driven gear Refer to "CLUTCH" section.Right crankcase cove

5-40OIL PUMPREMOVING THE OIL TANKOrder Part name Q'ty RemarksDrain the engine oil.Refer to "CHANGING THE ENGINE OIL" section in the CHA

5-41OIL PUMPCHECKING THE OIL PUMP1. Inspect:• Oil pump drive gear "1"• Oil pump drive shaft "2"• Rotor housing "3"• Oil

5-42KICK SHAFT AND SHIFT SHAFTKICK SHAFT AND SHIFT SHAFTREMOVING THE KICK SHAFT AND SHIFT SHAFTOrder Part name Q'ty RemarksOil pump Refer to &qu

5-43KICK SHAFT AND SHIFT SHAFT17 Pawl 218 Pawl pin 219 Spring 220 Bolt (stopper lever) 121 Stopper lever 122 Torsion spring 123 Segment 1 Refer to rem

5-44KICK SHAFT AND SHIFT SHAFTREMOVING THE KICK SHAFT ASSEMBLY1. Remove:• Kick shaft assembly "1"Unhook the torsion spring "2" fro

5-45KICK SHAFT AND SHIFT SHAFTINSTALLING THE SHIFT GUIDE AND SHIFT LEVER ASSEMBLY1. Install:• Spring "1"• Pawl pin "2"• Pawl "

1-6SPECIAL TOOLSValve spring compressorYM-4019, 90890-04019 This tool is needed to remove and install the valve assemblies.Clutch holding toolYM-91042

5-46KICK SHAFT AND SHIFT SHAFTINSTALLING THE KICK IDLE GEAR1. Install:• Kick idle gear "1"• Washer "2"• Circlip "3" • Ap

5-47AC MAGNETO AND STARTER CLUTCHAC MAGNETO AND STARTER CLUTCHREMOVING THE AC MAGNETO AND STARTER CLUTCHOrder Part name Q'ty RemarksDrain the eng

5-48AC MAGNETO AND STARTER CLUTCHTighten the rotor nut to 65 Nm (6.5 m•kg, 47 ft•lb), loosen and retighten the rotor nut to 65 Nm (6.5 m•kg, 47 ft•lb)

5-49AC MAGNETO AND STARTER CLUTCHREMOVING THE ROTOR1. Remove:• Nut (rotor) "1"• WasherUse the sheave holder "2".2. Remove:• Rotor

5-50AC MAGNETO AND STARTER CLUTCH2. Install:• Holder "1"• Bolt "2"Pass the pickup coil lead and charging coil lead under the holde

5-51AC MAGNETO AND STARTER CLUTCH• Bolt [crankcase cover (left)] "3"Tighten the bolts in stage, using a crisscross pattern.11. Install:• Was

5-52ENGINE REMOVALENGINE REMOVALREMOVING THE ENGINEOrder Part name Q'ty RemarksHold the machine by placing the suitable stand under the frame.Ref

5-53ENGINE REMOVALNegative battery lead Disconnect at the engine side.1 Engine guard 12 Neutral switch 13 Drive chain sprocket cover 14 Nut (drive spr

5-54ENGINE REMOVALHANDLING NOTESupport the machine securely so there is no danger of it falling over.REMOVING THE DRIVE SPROCKET1. Remove:• Nut (drive

5-55ENGINE REMOVALTighten the nut while applying the rear brake.3. Bend the lock washer tab to lock the nut.4. Install:• Drive chain sprocket guide &q

1-7SPECIAL TOOLSVacuum/pressure pump gauge setYB-35956-A, 90890-06756This tool is used to check the air in-duction system.YAMAHA Bond No. 1215 (ThreeB

5-56CRANKCASE AND CRANKSHAFTCRANKCASE AND CRANKSHAFTREMOVING THE CRANKSHAFTOrder Part name Q'ty RemarksEngie Refer to "ENGINE REMOVAL"

5-57CRANKCASE AND CRANKSHAFT9 Right crankcase 1 Refer to removal section.10 Left crankcase 1 Refer to removal section.11 Oil strainer 112 Crankshaft 1

5-58CRANKCASE AND CRANKSHAFTREMOVING THE CRANKCASE BEARINGOrder Part name Q'ty RemarksTransmissionRefer to "TRANSMISSION, SHIFT CAM AND SHIF

5-59CRANKCASE AND CRANKSHAFTDISASSEMBLING THE CRANKCASE1. Separate:• Right crankcase• Left crankcaseSeparation steps:a. Remove the crankcase bolts &qu

5-60CRANKCASE AND CRANKSHAFTCHECKING THE OIL STRAINER1. Inspect:• Oil strainerDamage→ Replace.CHECKING THE OIL DELIVERY PIPE 21. Inspect:• Oil deliver

5-61CRANKCASE AND CRANKSHAFT5. Install:• Dowel pin "1"• O-ring "2" • Right crankcaseTo left crankcase.• Apply the lithium soap bas

5-62TRANSMISSION, SHIFT CAM AND SHIFT FORKTRANSMISSION, SHIFT CAM AND SHIFT FORKREMOVING THE TRANSMISSION, SHIFT CAM AND SHIFT FORKOrder Part name Q&a

5-63TRANSMISSION, SHIFT CAM AND SHIFT FORKREMOVING THE TRANSMISSION1. Remove:• Main axle "1"• Drive axle "2"• Shift cam• Shift for

5-64TRANSMISSION, SHIFT CAM AND SHIFT FORK4. Install:• Collar "1"• Apply the lithium soap base grease on the oil seal lip.• When installing

6-1FRONT WHEEL AND REAR WHEELCHASSISFRONT WHEEL AND REAR WHEELREMOVING THE FRONT WHEELOrder Part name Q'ty RemarksHold the machine by placing the

1-8CONTROL FUNCTIONSCONTROL FUNCTIONSMAIN SWITCHFunctions of the respective switch po-sitions are as follows:ON:The engine can be started only at this

6-2FRONT WHEEL AND REAR WHEELREMOVING THE REAR WHEELOrder Part name Q'ty RemarksHold the machine by placing the suitable stand under the engine.R

6-3FRONT WHEEL AND REAR WHEELHANDLING NOTESupport the machine securely so there is no danger of it falling over.REMOVING THE REAR WHEEL1. Remove:• Whe

6-4FRONT WHEEL AND REAR WHEEL• Bolt (brake disc) "2" Tighten the bolts in stage, using a crisscross pattern.3. Install:• Collar "1"

6-5FRONT WHEEL AND REAR WHEEL2. Install:• Brake disc "1"• Bolt (brake disc) "2" Tighten the bolts in stage, using a crisscross pat

6-6FRONT BRAKE AND REAR BRAKEFRONT BRAKE AND REAR BRAKEREMOVING THE FRONT BRAKEOrder Part name Q'ty RemarksHold the machine by placing the suitab

6-7FRONT BRAKE AND REAR BRAKEREMOVING THE REAR BRAKEOrder Part name Q'ty RemarksHold the machine by placing the suitable stand under the engine.R

6-8FRONT BRAKE AND REAR BRAKEDISASSEMBLING THE BRAKE CALIPEROrder Part name Q'ty RemarksA. FrontB. RearAB1Pad pin 112 Brake pad 2 23 Pad support

6-9FRONT BRAKE AND REAR BRAKEDISASSEMBLING THE BRAKE MASTER CYLINDEROrder Part name Q'ty RemarksA. FrontB. Rear1 Brake master cylinder cap 12 Dia

6-10FRONT BRAKE AND REAR BRAKEHANDLING NOTESupport the machine securely so there is no danger of it falling over.DRAINING THE BRAKE FLUID1. Remove:• B

6-11FRONT BRAKE AND REAR BRAKEA. FrontB. RearCHECKING THE BRAKE CALIPER1. Inspect:• Brake caliper cylinder inner sur-face "a"Wear/score mark

1-9MULTI-FUNCTION DISPLAYCOLD STARTER KNOBWhen cold, the engine requires a richer air-fuel mixture for starting. A separate starter circuit, which is

6-12FRONT BRAKE AND REAR BRAKE• Pad pin plug "4"INSTALLING THE REAR BRAKE CALIPER1. Install:• Pad support "1"• Brake pad "2&q

6-13FRONT BRAKE AND REAR BRAKE2. Install:• Brake lever "1"• Bolt (brake lever) "2"• Nut (brake lever) "3"Apply the silic

6-14FRONT BRAKE AND REAR BRAKE• Nut (brake hose holder) "2"Align the top "a" of the brake hose holder with the paint "b"

6-15FRONT BRAKE AND REAR BRAKE3. Inspect:• Brake fluid levelFluid at lower level→ Fill up.Refer to "CHECKING THE BRAKE FLUID LEVEL" section

6-16FRONT FORKFRONT FORKREMOVING THE FRONT FORKOrder Part name Q'ty RemarksHold the machine by placing the suitable stand under the engine.Refer

6-17FRONT FORKDISASSEMBLING THE FRONT FORKOrder Part name Q'ty Remarks1 Front fork cap bolt 1 Refer to removal section.2 Fork spring 1 Drain the

6-18FRONT FORKHANDLING NOTESupport the machine securely so there is no danger of it falling over.The front fork requires careful atten-tion. So it is

6-19FRONT FORKThe bending value is shown by one half of the dial gauge reading.Do not attempt to straighten a bent inner tube as this may dangerous-ly

6-20FRONT FORK9. Install:• Slide metal "1"• Oil seal washer "2"To outer tube slot.Press the slide metal into the outer tube with f

6-21FRONT FORKBe sure to install the spring guide "2" when checking the oil level.Never fail to make the oil level ad-justment between the m

1-10MULTI-FUNCTION DISPLAYTo reset the digits, select the tripme-ter involved and push the "RST" but-ton for 2 seconds or more.CHANGEOVER TO

6-22FRONT FORK4. Tighten:• Pinch bolt (upper bracket) "1"• Pinch bolt (lower bracket) "2"Tighten the lower bracket to speci-fied t

6-23HANDLEBARHANDLEBARREMOVING THE HANDLEBAROrder Part name Q'ty RemarksHeadlight 1 Hot starter cable 1 Disconnect at the lever side.2 Hot starte

6-24HANDLEBARREMOVING THE BRAKE MASTER CYLINDER1. Remove:• Brake master cylinder bracket "1"• Brake master cylinder "2"• Do not le

6-25HANDLEBAR5. Install:• Right grip "1"• Collar "2"Apply the adhesive on the tube guide "3".• Before applying the adhes

6-26HANDLEBARApply the lithium soap base grease on the clutch cable end and hot start-er cable end.13. Adjust:• Clutch lever free playRefer to "A

6-27STEERINGSTEERINGREMOVING THE STEERINGOrder Part name Q'ty RemarksTIGHTENING STEPS:• Tighten ring nut. 38 Nm (3.8 m•kg, 27 ft•lb)• Loosen it o

6-28STEERING9 Bearing race cover 110 Upper bearing 111 Lower bearing 1 Refer to removal section.12 Bearing race 2 Refer to removal section.Order Part

6-29STEERINGHANDLING NOTESupport the machine securely so there is no danger of it falling over.REMOVING THE STEERING RING NUT1. Remove:• Steering ring

6-30STEERING7. Install:• Front fork "1"• Upper bracket "2"• Main switch "3"• Front brake hose guide bracket "4"

6-31SWINGARMSWINGARMREMOVING THE SWINGARMOrder Part name Q'ty RemarksHold the machine by placing the suitable stand under the engine.Refer to &qu

1-11MULTI-FUNCTION DISPLAY3. Run the machine and start timer measurement.4. To stop timer measurement, pushing the "SLCT1" button and "

6-32SWINGARMDISASSEMBLING THE SWINGARMOrder Part name Q'ty Remarks1 Cap 2 Refer to removal section.2 Relay arm 13 Connecting rod 14 Collar 25 Oil

6-33SWINGARMHANDLING NOTESupport the machine securely so there is no danger of it falling over.REMOVING THE CAP1. Remove:• Left cap "1"Remov

6-34SWINGARMINSTALLING THE SWINGARM1. Install:• Bushing "1"• Thrust bearing "2"• Oil seal "3"• Collar "4"To sw

6-35SWINGARM11. Tighten:• Nut (relay arm) "1"12. Install:• Cap "1"Install the right cap with its mark "a" facing forward

6-36REAR SHOCK ABSORBERREAR SHOCK ABSORBERREMOVING THE REAR SHOCK ABSORBEROrder Part name Q'ty RemarksHold the machine by placing the suitable st

6-37REAR SHOCK ABSORBER3 CDI unit coupler 34 Plastic band 15 Clamp (air filter joint) 1 Only loosening.6Rear frame 17 Bolt (rear shock absorber-relay

6-38REAR SHOCK ABSORBERHANDLING NOTE• Support the machine securely so there is no danger of it falling over.• This rear shock absorber is pro-vided wi

6-39REAR SHOCK ABSORBER3. Install:• Lower bearing "1"Install the bearing by pressing it on the side having the manufacture's marks or n

6-40REAR SHOCK ABSORBER8. Install:• Plastic band• Taillight coupler• Locking tie

7-1ELECTRICAL COMPONENTS AND WIRING DIAGRAMELECTRICALELECTRICAL COMPONENTS AND WIRING DIAGRAMELECTRICAL COMPONENTS1. Headlight2. Multi-function displa

1-12MULTI-FUNCTION DISPLAYFUNCTION DIAGRAMA short push on the button changes the operation in the arrowed direction.A short push on the button changes

7-2ELECTRICAL COMPONENTS AND WIRING DIAGRAMWIRING DIAGRAM1. Headlight2. Multi-function display3. Engine stop switch4. Clutch switch5. Diode6. Starter

7-3IGNITION SYSTEMIGNITION SYSTEMINSPECTION STEPSUse the following steps for checking the possibility of the malfunctioning engine being attributable

7-4IGNITION SYSTEMSPARK GAP TEST1. Disconnect the ignition coil from spark plug.2. Remove the ignition coil cap.3. Connect the dynamic spark tester &q

7-5ELECTRIC STARTING SYSTEM4. Inspect:• Sealed portion of ignition coil "a"• Spark plug terminal pin "b"• Threaded portion of spar

7-6ELECTRIC STARTING SYSTEMINSPECTION STEPSIf the starter motor will not operate, use the following inspection steps.*1 marked: Refer to "CHECKIN

7-7ELECTRIC STARTING SYSTEMCHECKING THE COUPLERS AND LEADS CONNECTION1. Check:• Couplers and leads connectionRust/dust/looseness/short-circuit→ Repair

7-8ELECTRIC STARTING SYSTEM2. Inspect:• Rubber part "a"Tears/damage→ Replace.

7-9ELECTRIC STARTING SYSTEMREMOVING THE STARTER MOTOROrder Part name Q'ty RemarksExhaust pipeRefer to "EXHAUST PIPE AND SILENCER" secti

7-10ELECTRIC STARTING SYSTEMDISASSEMBLING THE STARTER MOTOROrder Part name Q'ty Remarks1 Starter motor front cover 12 Washer (starter motor front

7-11ELECTRIC STARTING SYSTEMCHECKING AND REPAIRING THE STARTER MOTOR1. Check:• CommutatorDirt→Clean with 600 grit sandpa-per.2. Measure:• Commutator d

1-13MULTI-FUNCTION DISPLAYThe following diagram illustrates the multi-function display regarding the direction and operation condition in-volved in ea

7-12ELECTRIC STARTING SYSTEM5. Install:• Gasket• Bolt "1"• O-ring "2" Apply the lithium soap base grease on the O-ring.

7-13CHARGING SYSTEMCHARGING SYSTEMINSPECTION STEPSIf the battery is not charged, use the following inspection steps.*1 marked: Refer to "CHECKING

7-14CHARGING SYSTEMCHECKING THE COUPLERS AND LEADS CONNECTION1. Check:• Couplers and leads connectionRust/dust/looseness/short-circuit→ Repair or repl

7-15THROTTLE POSITION SENSOR SYSTEMTHROTTLE POSITION SENSOR SYSTEMINSPECTION STEPSIf the throttle position sensor will not operate, use the following

7-16THROTTLE POSITION SENSOR SYSTEMHANDLING NOTEDo not loosen the screw (throttle position sensor) "1" except when changing the throttle pos

7-17THROTTLE POSITION SENSOR SYSTEM10. Put the aligning marks "a" on the throttle position sensor and car-buretor.11. Stop the engine.12. Re

7-18LIGHTING SYSTEMLIGHTING SYSTEMINSPECTION STEPSRefer to the following flow chart when inspecting the lighting system for possible problems.• Remove

7-19LIGHTING SYSTEMCHECKING THE TAILLIGHT (LEDs)1. Disconnect the taillight coupler.2. Connect two jumper leads "1" from the battery termina

7-20SIGNALING SYSTEMSIGNALING SYSTEMINSPECTION STEPSIf the speedometer will not operate, use the following inspection steps.*1 marked: Refer to "

7-21SIGNALING SYSTEMCHECKING THE COUPLERS AND LEADS CONNECTION1. Check:• Couplers and leads connectionRust/dust/looseness/short-circuit→ Repair or rep

1-14STARTING AND BREAK-INSTARTING AND BREAK-INFUELAlways use the recommended fuel as stated below. Also, be sure to use new gasoline the day of a race

YAMAHA MOTOR CO., LTD.2500 SHINGAI IWATA SHIZUOKA JAPANPRINTED ON RECYCLED PAPER PRINTED IN JAPAN2007.08-0.8×1 CR(E)

1-15STARTING AND BREAK-INThe engine fails to startPull the hot starter lever all the way out and while holding the lever, kick the kickstarter crank 1

1-16TORQUE-CHECK POINTSTORQUE-CHECK POINTSConcerning the tightening torque, refer to "TIGHTENING TORQUES" section in the CHAPTER 2.Frame con

1-17CLEANING AND STORAGECLEANING AND STORAGECLEANINGFrequent cleaning of your machine will enhance its appearance, maintain good overall performance,

2-1GENERAL SPECIFICATIONSSPECIFICATIONSGENERAL SPECIFICATIONSModel name: WR250FX (USA, CDN, AUS, NZ)WR250F (ZA)Model code number: 5UMH (USA)5UMK (CDN)

2-2GENERAL SPECIFICATIONSAir filter: Wet type elementFuel:Type Premium unleaded gasoline only with a research octane number of 95 or higher.Tank capac

2-3MAINTENANCE SPECIFICATIONSMAINTENANCE SPECIFICATIONSENGINEShock absorber:Front shock absorber Coil spring/oil damperRear shock absorber Coil spring

2-4MAINTENANCE SPECIFICATIONSIntake "A" 29.65–29.75 mm (1.1673–1.1713 in) 29.55 mm (1.1634 in)Intake "B" 22.45–22.55 mm (0.8839–0.

WR250F (X)OWNER'S SERVICE MANUAL©2007 by Yamaha Motor Co., Ltd.1st Edition, July 2007All rights reserved. Any reprinting orunauthorized use witho

2-5MAINTENANCE SPECIFICATIONS"D" margin thickness (IN) 0.8 mm (0.0315 in) ----"D" margin thickness (EX) 0.7 mm (0.0276 in) ----Ste

2-6MAINTENANCE SPECIFICATIONSTilt limit* (IN) ---- 2.5°/1.6 mm (2.5°/0.063 in)Tilt limit* (EX) ---- 2.5°/1.6 mm (2.5°/0.063 in)Direction of winding (t

2-7MAINTENANCE SPECIFICATIONSOil ring:Dimensions (B × T) 1.50 × 2.25 mm (0.06 × 0.09 in) ----End gap (installed) 0.10–0.40 mm (0.004–0.016 in) ----Cra

2-8MAINTENANCE SPECIFICATIONSCarburetor:Type/manufacturer FCR-MX37/KEIHIN ----I. D. mark 5UME E0 ----Main jet (M.J) #170 ----Main air jet (M.A.J) #115

2-9MAINTENANCE SPECIFICATIONSCHASSISItem Standard LimitSteering system:Steering bearing type Taper roller bearing ----Front suspension:Front fork trav

2-10MAINTENANCE SPECIFICATIONSELECTRICALFront disc brake:Disc outside dia.×Thickness 250 × 3.0 mm (9.84 × 0.12 in) 250 × 2.5 mm (9.84 × 0.10 in)Pad th

2-11TIGHTENING TORQUESTIGHTENING TORQUESENGINE△ - marked portion shall be checked for torque tightening after break-in or before each race.Rectifier/r

2-12TIGHTENING TORQUESCylinder M6 × 1.0 1 10 1.0 7.2Balancer weight M6 × 1.0 2 10 1.0 7.2Balancer shaft driven gear M14 × 1.0 1 50 5.0 36Timing chain

2-13TIGHTENING TORQUESCHASSIS△ - marked portion shall be checked for torque tightening after break-in or before each race.Air induction pipe M6 × 1.0

2-14TIGHTENING TORQUES△ Front fork and front fork protector M6 × 1.0 6 7 0.7 5.1△ Front fork protector and brake hose holder M6 × 1.0 2 7 0.7 5.1Throt

FOREWORDINTRODUCTIONCongratulations on your purchase of a Yamaha WR series. This model is the culmination of Yamaha's vast ex-perience in the pro

2-15TIGHTENING TORQUES1. First, tighten the steering ring nut approximately 38 Nm (3.8 m•kg, 27 ft•lb) by using the steering nut wrench, then loosen t

2-16TIGHTENING TORQUESELECTRICALTighten the rotor nut to 65 Nm (6.5 m•kg, 47 ft•lb), loosen and retighten the rotor nut to 65 Nm (6.5 m •kg, 47 ft•lb)

2-17TIGHTENING TORQUESGENERAL TORQUE SPECIFICATIONSThis chart specifies torque for stan-dard fasteners with standard I.S.O. pitch threads. Torque spec

2-18TIGHTENING TORQUES

2-19LUBRICATION DIAGRAMSLUBRICATION DIAGRAMS1. Oil filter element2. Oil pump3. Drive axle4. Main axle5. Intake camshaft6. Exhaust camshaft7. Oil tank8

2-20LUBRICATION DIAGRAMS1. Crankshaft2. Oil filter element3. Oil tank4. Oil hoseA. From oil pump

2-21CABLE ROUTING DIAGRAMCABLE ROUTING DIAGRAM1. Fuel tank breather hose2. Clamp3. Diode4. Hot starter cable5. Wire harness6. Hump (frame)7. Cylinder

2-22CABLE ROUTING DIAGRAMB. Fasten the throttle cable, hot starter cable and rectifier/regula-tor lead onto the frame. Locate the clamp end facing the

2-23CABLE ROUTING DIAGRAM1. Throttle cable (pull)2. Throttle cable (return)3. Catch tank hose4. Ignition coil5. Clamp6. Air induction hose (air cut-of

2-24CABLE ROUTING DIAGRAM1. Brake master cylinder2. Brake hose holder3. Brake hoseA. Install the brake hose so that its pipe portion directs as shown

TO THE NEW OWNERThis manual will provide you with a good basic understanding of fea-tures, operation, and basic mainte-nance and inspection items of t

2-25CABLE ROUTING DIAGRAM1. Clamp2. Positive battery lead3. Battery4. Negative battery lead5. Taillight coupler6. CDI unit coupler (6-pin)7. CDI unit

2-26CABLE ROUTING DIAGRAMC. Pass the starter motor lead through the hole in the relay holder.D. Fit the cover securely.E. Connect the wire harness to

2-27CABLE ROUTING DIAGRAM1. Throttle cable2. Clamp3. Brake hose4. Clutch cable5. Hose guide6. Main switch coupler7. Wire harness8. Headlight coupler9.

2-28CABLE ROUTING DIAGRAME. Pass the throttle cables, clutch cable and hot starter cable be-tween the upper bracket and multi-function display bracket

3-1MAINTENANCE INTERVALSREGULAR INSPECTION AND ADJUSTMENTSMAINTENANCE INTERVALSThe following schedule is intended as a general guide to maintenance an

3-2MAINTENANCE INTERVALSCLUTCHInspect and adjust●● Inspect housing, friction plate, clutch plate and spring.Replace●TRANSMISSIONInspect●Replace bearin

3-3MAINTENANCE INTERVALSFUEL TANK, COCKClean and inspect●●BRAKESAdjust lever position and pedal height●●Lubricate pivot point ●●Check brake disc surfa

3-4MAINTENANCE INTERVALSTIRE, WHEELSInspect air pressure, wheel run-out, tire wear and spoke loose-ness●●Retighten sprocket bolt ●●Inspect bearings ●R

3-5PRE-OPERATION INSPECTION AND MAINTENANCEPRE-OPERATION INSPECTION AND MAINTENANCEBefore riding for break-in operation or practice, make sure the mac

3-6ENGINEENGINEREMOVING THE SEAT, FUEL TANK AND SIDE COVERSOrder Part name Q'ty RemarksTurn the fuel cock to "OFF".Disconnect the fuel

HOW TO READ DESCRIPTIONSTo help identify parts and clarify pro-cedure steps, there are exploded dia-grams at the start of each removal and disassembly

3-7ENGINEREMOVING THE SIDE COVER1. Remove:• Bolt (side cover)• Right side cover "1"Draw the side cover backward to re-move it because its cl

3-8ENGINEREMOVING THE EXHAUST PIPE AND SILENCEROrder Part name Q'ty RemarksRight side coverRefer to "SEAT, FUEL TANK AND SIDE COVERS" s

3-9ENGINECHECKING THE SILENCER AND EXHAUST PIPE1. Inspect:• Gasket "1"Damage→ Replace.INSTALLING THE SILENCER AND EXHAUST PIPE1. Install:• G

3-10ENGINEHandling notes of coolant:The coolant is harmful so it should be handled with special care.• When coolant splashes to your eye.Thoroughly wa

3-11ENGINE2. Adjust:• Throttle grip free playThrottle grip free play adjustment steps:a. Slide the adjuster cover.b. Loosen the locknut "1".

3-12ENGINE5. Inspect:• Air filter elementDamage→ Replace.6. Apply:• Foam-air-filter oil or equivalent oil to the element• Squeeze out the excess oil.

3-13ENGINE• Oil filler cap "4"• Oil tank drain bolt "5"• Crankcase oil drain bolt "6"• Oil filter element drain bolt &qu

3-14ENGINEADJUSTING THE ENGINE IDLING SPEED1. Start the engine and thoroughly warm it up.2. Adjust:• Engine idling speedAdjustment steps:a. Turn the t

3-15ENGINE• Place a rag in the timing chain space to prevent pads from falling into the crankcase.• Identity each valve lifter and pad position very c

3-16ENGINEINTAKEEXHAUST

TABLE OF CONTENTSGENERAL INFORMATION1SPECIFICATIONS2REGULAR INSPECTION AND ADJUSTMENTS3TUNING4ENGINE5CHASSIS6ELECTRICAL7

3-17CHASSISCLEANING THE SPARK ARRESTER (For USA)• Be sure the exhaust pipe and si-lencer are cool before cleaning the spark arrester.• Do not start th

3-18CHASSIS2. Remove:• Brake lever cover3. Adjust:• Brake lever positionBrake lever position adjustment steps:a. Loosen the locknut "1".b. T

3-19CHASSISi. Install the brake caliper "8" and tighten the pad pin "9".j. Install the pad pin plug "10".3. Inspect:• Br

3-20CHASSIS3. Inspect:• Brake fluid levelRefer to "CHECKING THE BRAKE FLUID LEVEL" section.4. Check:• Brake pedal operationA softy or spongy

3-21CHASSISWhen installing the drive chain, apply the lithium soap base grease on the chain joint and O-rings.7. Install:• Link plate• Press the link

3-22CHASSIS1. Elevate the front wheel by placing a suitable stand under the engine.2. Remove the air bleed screw "1" and release the interna

3-23CHASSISNever attempt to turn the adjuster beyond the maximum or minimum setting.5. Tighten:• Locknut6. Install:• Rear frame (upper)• Rear frame (l

3-24CHASSISCHECKING THE TIRE PRESSURE1. Measure:• Tire pressureOut of specification→ Adjust.• Check the tire while it is cold.• Loose bead stoppers al

3-25CHASSIS• Install the collar "6" with the larger inside diameter facing downward.• The handlebar upper holder should be installed with th

3-26CHASSISLUBRICATIONTo ensure smooth operation of all components, lubricate your machine during setup, after break-in, and after every race.1. All c

CONTENTSCHAPTER 1GENERAL INFOR-MATIONDESCRIPTION ... 1-1MACHINE IDENTIFICATION ... 1-2INCLUDED PARTS ... 1-2IMPORTANT I

3-27ELECTRICALELECTRICALCHECKING THE SPARK PLUG1. Remove:• Spark plug2. Inspect:• Electrode "1"Wear/damage→ Replace.• Insulator color "

3-28ELECTRICAL3. Remove:• Battery band• Battery4. Measure:• Battery chargeMeasurement steps:a. Connect a pocket tester "1" to the battery te

3-29ELECTRICALCharging method using a variable voltage charger

3-30ELECTRICALCharging method using a constant voltage charger

3-31ELECTRICAL6. Install:• Battery• Battery band7. Connect:• Battery leads(to the battery terminals)First, connect the positive lead "1", th

3-32ELECTRICALADJUSTING THE HEADLIGHT BEAMS1. Adjust:• Headlight beam (vertically)Adjusting steps:a. Turn the adjusting screw "1" in di-rect

4-1ENGINETUNINGENGINECARBURETOR SETTING• The air/fuel mixture will vary de-pending on atmospheric conditions. Therefore, it is necessary to take into

4-2ENGINEADJUSTING THE PILOT JETThe richness of the air-fuel mixture with the throttle open 1/4 or less can be set by adjusting the pilot jet "1&

4-3ENGINECARBURETOR SETTING PARTSMain jet SizePart number (-14943-)Rich #182 4MX-94#180 4MX-43#178 4MX-93#175 4MX-42#172 4MX-92(STD) #170 4MX-41#168 4

4-4ENGINEEXAMPLES OF CARBURETOR SETTING DEPENDING ON SYMPTOM* This should be taken simply for an example. It is necessary to set the carburetor while

1-1DESCRIPTIONGENERAL INFORMATIONDESCRIPTION• The machine you have purchased may differ slightly from those shown in the following.• Designs and speci

4-5CHASSISCHASSISSELECTION OF THE SECONDARY REDUCTION RATIO (SPROCKET)<Requirement for selection of sec-ondary gear reduction ratio>• It is gene

4-6CHASSISA. Air spring characteristics in relation to oil level changeB. LoadC. Stroke1. Max. oil level2. Standard oil level3. Min. oil levelADJUSTIN

4-7CHASSISCHOOSING SET LENGTH1. Place a stand or block under the engine to put the rear wheel above the floor, and measure the length "a" be

4-8CHASSISSUSPENSION SETTING (FRONT FORK)• If any of the following symptoms is experienced with the standard position as the base, make resetting by r

4-9CHASSISSUSPENSION SETTING (REAR SHOCK ABSORBER)• If any of the following symptoms is experienced with the standard position as the base, make reset

5-1RADIATORENGINERADIATORREMOVING THE RADIATOROrder Part name Q'ty RemarksDrain the coolant.Refer to "CHECKING THE COOLANT" sec-tion in

5-2RADIATOR13 Catch tank breather hose 114 Catch tank 1Order Part name Q'ty Remarks

5-3RADIATORHANDLING NOTEDo not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be blown out under press

5-4CARBURETORCARBURETORREMOVING THE CARBURETOROrder Part name Q'ty RemarksSeat and fuel tank Refer to "SEAT, FUEL TANK AND SIDE COVERS"

5-5CARBURETORDISASSEMBLING THE CARBURETOROrder Part name Q'ty Remarks1 Carburetor breather hose 42 Valve lever housing cover 13 Screw (throttle s