Yamaha YFZ450X Service Manual

CHAPTER 1GENERAL INFORMATIONMACHINE IDENTIFICATION...1-1VEHICLE IDENTIFICATIO

3 - 29CHKADJCHANGING THE COOLANT5. Install: • coolant reservoir • coolant reservoir bolts 6. Connect: • coolant reservoir breather hose T R..7 Nm (0.7

3 - 30CHKADJCHANGING THE COOLANT12.Fill: • cooling system (with the specified amount of the recom-mended coolant)Handling notes for coolantCoolant is

3 - 31CHKADJCHANGING THE COOLANT14.Fill: • coolant reservoir (with the recommended coolant to the maxi-mum level mark a)15.Install: • coolant reservoi

3 - 32CHKADJCHECKING THE COOLANT TEMPERATURE WARNINGLIGHTEBS00077CHECKING THE COOLANT TEMPERATURE WARNING LIGHT1Coolant temperature warning light1Cool

3 - 33CHKADJCLEANING THE SPARK ARRESTER 1. Clean:• Spark arrester▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼WARNING• Select a well-ventilated area fre

3 - 34CHKADJADJUSTING THE FRONT BRAKE/ADJUSTING THEBRAKE LEVER/ADJUSTING THE REAR BRAKEEBS00080CHASSISADJUSTING THE FRONT BRAKE1. Measure: • brake lev

3 - 35CHKADJADJUSTING THE REAR BRAKE/ADJUSTING THE PARKING BRAKE2. Adjust: • rear brake pedal height▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Loos

3 - 36CHKADJADJUSTING THE PARKING BRAKE/CHECKING THE BRAKE FLUID LEVEL2. Adjust:• parking brake cable end length▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼

3 - 37CHKADJCHECKING THE BRAKE FLUID LEVEL/CHECKING THE FRONT BRAKE PADS2. Check: • brake fluid level Below the minimum level mark 1 → Addthe recomme

3 - 38CHKADJCHECKING THE FRONT BRAKE PADS/CHECKING THE REAR BRAKE PADS2. Check: • brake pads Wear indicators 1 almost touch the brakedisc → Replace th

CHAPTER 3PERIODIC CHECKS AND ADJUSTMENTSINTRODUCTION...3-1

3 - 39CHKADJADJUSTING THE REAR BRAKE LIGHT SWITCH/CHECKING THE BRAKE HOSESADJUSTING THE REAR BRAKE LIGHT SWITCHNOTE:• The rear brake light switch is o

3 - 40CHKADJCHECKING THE BRAKE HOSES/BLEEDING THE HYDRAULIC BRAKE SYSTEM2. Check: • front brake hoses 1 • rear brake hose 2 Cracks/wear/damage → Repla

3 - 41CHKADJBLEEDING THE HYDRAULIC BRAKE SYSTEMNOTE:_ • Be careful not to spill any brake fluid or allowthe brake master cylinder reservoir or brakefl

3 - 42CHKADJBLEEDING THE HYDRAULIC BRAKE SYSTEM/ADJUSTING THE SHIFT PEDALi. Repeat steps (e) to (h) until all of the airbubbles have disappeared from

3 - 43CHKADJADJUSTING THE DRIVE CHAIN SLACKADJUSTING THE DRIVE CHAIN SLACKNOTE:Measure the drive chain slack halfwaybetween the drive axle and the rea

3 - 44CHKADJADJUSTING THE DRIVE CHAIN SLACK/CHECKING THE STEERING SYSTEMCAUTION:Excessive chain slack will overload theengine and other vital parts; k

3 - 45CHKADJADJUSTING THE TOE-INEBS00108ADJUSTING THE TOE-IN1. Place the machine on a level surface.2. Measure: • toe-in Out of specification → Adjust

3 - 46CHKADJADJUSTING THE TOE-IN/CHECKING THE FRONT ANDREAR SHOCK ABSORBERS▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Mark both tie-rods ends. This

3 - 47CHKADJADJUSTING THE FRONT SHOCK ABSORBERSEBS00111ADJUSTING THE FRONT SHOCK ABSORBERSWARNING_ Always adjust the spring preload, rebounddamping fo

3 - 48CHKADJADJUSTING THE FRONT SHOCK ABSORBERSNOTE:_ Always tighten the locknut against the adjust-ing ring, then torque it to specification. ▲▲▲▲ ▲

CHECKING THE WHEELS ...3-55CHECKING AND LUBRICATING THE CABLES ...

3 - 49CHKADJADJUSTING THE FRONT SHOCK ABSORBERS/ADJUSTING THE REAR SHOCK ABSORBER3. Adjust: • compression damping force▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼

3 - 50CHKADJADJUSTING THE REAR SHOCK ABSORBER3. Disconnect the air filter case breather hose1, and then remove the air filter case 2with the air intak

3 - 51CHKADJADJUSTING THE REAR SHOCK ABSORBERNOTE:_ Always tighten the locknut against the adjust-ing ring, then torque it to specification. ▲▲▲▲ ▲ ▲▲

3 - 52CHKADJADJUSTING THE REAR SHOCK ABSORBER7. Adjust: • compression damping force▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Turn the adjusting sc

3 - 53CHKADJCHECKING THE TIRESEBS00114CHECKING THE TIRESWARNING_ This model is equipped with low pressuretires. It is important that they be inflatedc

3 - 54CHKADJCHECKING THE TIRES1. Measure: • tire pressure Out of specification → Adjust. NOTE:_ • The low-pressure tire gauge 1 is includedas standard

3 - 55CHKADJCHECKING THE WHEELS/CHECKING ANDLUBRICATING THE CABLESEBS00116CHECKING THE WHEELS1. Check: • wheel 1 Damage/bends → Replace.NOTE:_ Always

3 - 56CHKADJLUBRICATING THE LEVERS AND PEDALSEBS00118LUBRICATING THE LEVERS AND PEDALS Lubricate the pivoting point and metal-to-metalmoving parts of

3 - 57CHKADJEBS00120ELECTRICAL SYSTEMCHECKING AND CHARGING THE BATTERYWARNING_ Batteries generate explosive hydrogen gasand contain electrolyte which

3 - 58CHKADJCHECKING AND CHARGING THE BATTERYNOTE:_ Since MF batteries are sealed, it is not possi-ble to check the charge state of the battery bymeas

CYLINDER AND PISTON...4-34REMOVING THE PISTON ...

3 - 59CHKADJCHECKING AND CHARGING THE BATTERYNOTE:_ • The charge state of an MF battery can bechecked by measuring its open-circuit volt-age (i.e., th

3 - 60CHKADJCHECKING AND CHARGING THE BATTERY• Before removing the battery charger leadclips from the battery terminals, be sureto turn off the batter

3 - 61CHKADJCHECKING AND CHARGING THE BATTERYCharging method using a variable-current (voltage) chargerMeasure the open-circuitvoltage prior to chargi

3 - 62CHKADJCHECKING AND CHARGING THE BATTERYCharging method using a constant voltage chargerMeasure the open-circuitvoltage prior to charging.NOTE:Se

3 - 63CHKADJCHECKING AND CHARGING THE BATTERY7. Install: • battery8. Install: • battery holding bracketRefer to “SEAT, FENDERS AND FUELTANK”.9. Connec

3 - 64CHKADJCHECKING THE FUSESEBS00121CHECKING THE FUSES The following procedure applies to all of thefuses. CAUTION:_ To avoid a short circuit, alway

3 - 65CHKADJCHECKING THE FUSES/ADJUSTING THE HEADLIGHT BEAMWARNING_ Never use a fuse with an amperage ratingother than that specified. Improvising oru

3 - 66CHKADJREPLACING A HEADLIGHT BULBEBS00124REPLACING A HEADLIGHT BULB1. Remove: • headlightRefer to “SEAT, FENDERS AND FUELTANK”.2. Disconnect: • h

3 - 67CHKADJREPLACING A HEADLIGHT BULB6. Install: • bulb holder • headlight bulb holder cover 1NOTE:After installing the bulb holder cover, makesure t

4 - 1ENGENGINE REMOVALEBS00198ENGINE ENGINE REMOVALMUFFLER AND EXHAUST PIPET R..13 Nm (1.3 m • kg, 9.4 ft • Ib)T R..20 Nm (2.0 m • kg, 14 ft • Ib)T R.

CRANKCASE ...4-65OIL SEAL AND BEARING...

4 - 2ENGENGINE REMOVALINSTALLING THE EXHAUST PIPE AND MUFFLER1. Install:• gasket 1(to muffler)NOTE:Install the gasket with the chamfer a, locatedon an

4 - 3ENG4. Install:• clampNOTE:Slide the clamp onto the end of the muffler andinsert the projection a of the clamp into a slotb in the muffler. Tighte

4 - 4ENGENGINE REMOVALEBS00204LEADS, CABLES AND HOSES6785141312114103219T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)NewNew

4 - 5ENGENGINE REMOVAL6785141312114103219T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)NewNewLSLST R..8 Nm (0.8 m • kg, 5.8

4 - 6ENGENGINE REMOVALEBS00205ENGINE MOUNTING BOLTS7122154313125961081112T R..26 Nm (2.6 m • kg, 19 ft • Ib)T R..40 Nm (4.0 m • kg, 29 ft • Ib)T R..10

4 - 7ENG7122154313125961081112T R..26 Nm (2.6 m • kg, 19 ft • Ib)T R..40 Nm (4.0 m • kg, 29 ft • Ib)T R..100 Nm (10.0 m • kg, 72 ft • lb)T R..33 Nm (3

4 - 8ENGENGINE REMOVALEBS00206INSTALLING THE ENGINE1. Install: • pivot shaft/nut/washer 1• engine upper bracket (left) 2 • engine upper bracket (right

4 - 9ENGCAMSHAFTSEBS00208 CAMSHAFTSCYLINDER HEAD COVEROrder Job/Part Q’ty RemarksRemoving the cylinder head coverRemove the parts in the order listed.

4 - 10ENGCAMSHAFTSCAMSHAFTSOrder Job/Part Q’ty RemarksRemoving the camshaftsRemove the parts in the order listed.1 Tensioner cap bolt 1Refer to “REMOV

4 - 11ENGCAMSHAFTSREMOVING THE CAMSHAFTS1. Remove:• timing mark accessing screw 1• crankshaft end accessing screw 22. Align:•“I” mark on the A.C. magn

CHAPTER 7CHASSISFRONT AND REAR WHEELS...7-1FRONT WHEELS ...

4 - 12ENGCAMSHAFTS6. Remove:• exhaust camshaft 1• intake camshaft 2• clips NOTE:To prevent the timing chain from falling into thecrankcase, fasten it

4 - 13ENGCAMSHAFTS4. Measure:• camshaft-journal-to-camshaft-cap clearanceOut of specification → Measure the cam-shaft journal diameter.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼

4 - 14ENGCAMSHAFTSEBS00224CHECKING THE CAMSHAFT SPROCKETS1. Check: • camshaft sprockets Wear/damage → Replace the camshaftsprockets and timing chain a

4 - 15ENGCAMSHAFTSEBS00228CHECKING THE TIMING CHAIN TENSIONER1. Check: • chain tensioner rod Damage/wear → Replace.2. Check: • timing chain tensioner

4 - 16ENGCAMSHAFTS2. Install: • clips • intake camshaft cap 1• exhaust camshaft cap 2• camshaft cap boltsNOTE:Tighten the camshaft cap bolts in stages

4 - 17ENGCAMSHAFTSd. Remove the screwdriver, mark sure that thetiming chain tensioner rod releases, andthen tighten the cap bolt to the specifiedtorqu

4 - 18ENGCYLINDER HEADCYLINDER HEAD Order Job/Part Q’ty RemarksRemoving the cylinder headRemove the parts in the order listed.Seat/fuel tank cover/sid

4 - 19ENGCYLINDER HEADNOTE:*1: Tighten the cylinder head bolts to 30 Nm (3.0 m · kg, 22 ft · lb) in the proper tightening sequence,remove and retighte

4 - 20ENGCYLINDER HEADREMOVING THE CYLINDER HEAD1. Remove:• cylinder headNOTE:• Loosen the bolts in the proper sequence.• Follow the numerical order s

4 - 21ENGCYLINDER HEADNOTE:_ To ensure an even surface, rotate the cylinderhead several times. ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲CHECKING THE

INSTALLING THE HANDLEBAR ...7-44INSTALLING THE HANDLEBAR GRIPS ...

4 - 22ENGCYLINDER HEAD3. Install:• washers• bolts 1: = 159 mm (6.26 in)• bolts 2: = 149 mm (5.87 in)▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼NOT

4 - 23ENGCYLINDER HEADh. Put a mark on the corner 1 of the cylinderhead bolt and the cylinder head 2 asshown.NOTE:Tighten the bolts 90° in each of the

4 - 24ENGVALVES AND VALVE SPRINGSEBS00234VALVES AND VALVE SPRINGSOrder Job/Part Q’ty RemarksRemoving the valves and valve springsRemove the parts in t

4 - 25ENGVALVES AND VALVE SPRINGSOrder Job/Part Q’ty Remarks7Stem seal 5Refer to “REMOVING THE VALVES AND VALVE SPRINGS” and “INSTALLING THE VALVES AN

4 - 26ENGVALVES AND VALVE SPRINGSEBS00238REMOVING THE VALVES AND VALVE SPRINGSThe following procedure applies to all of thevalves and related componen

4 - 27ENGVALVES AND VALVE SPRINGSValve spring compressor P/N. YM-04019, 90890-04019Valve spring compressor attach-ment P/N. YM-04114, 90890-041144. Re

4 - 28ENGVALVES AND VALVE SPRINGS2. Replace: • valve guide▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼NOTE:_ To ease guide removal, installation and to

4 - 29ENGVALVES AND VALVE SPRINGS4. Measure: • margin thickness a Out of specification → Replace.5. Measure: • valve stem runoutOut of specification →

4 - 30ENGVALVES AND VALVE SPRINGS▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Apply Mechanic’s blueing dye (Dykem) b tothe valve face. b. Install the

4 - 31ENGVALVES AND VALVE SPRINGSf. Apply Mechanic’s blueing dye (Dykem) tothe valve face. g. Install the valve into the cylinder head. h. Press the v

CHAPTER 8ELECTRICALELECTRICAL COMPONENTS...8-1CHECKING SWITCH CONTINUITY...

4 - 32ENGVALVES AND VALVE SPRINGS12.Measure: • valve spring tilt a Out of specification → Replace.Valve spring tilt limit Intake 2.5°/1.61 mm (0.063 i

4 - 33ENGVALVES AND VALVE SPRINGS3. Install: • valve cottersNOTE:_ Install the valve cotters while compressing thevalve spring with the valve spring c

4 - 34ENGCYLINDER AND PISTONEBS00245CYLINDER AND PISTONOrder Job/Part Q’ty RemarksRemoving the cylinder and pistonRemove the parts in the order listed

4 - 35ENGCYLINDER AND PISTONEBS00247REMOVING THE PISTON1. Remove: • piston pin clips 1 • piston pin 2 • piston 3NOTE:_ Before removing each piston pin

4 - 36ENGCYLINDER AND PISTON2. Measure: • piston-to-cylinder clearance▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Measure the cylinder bore “C” with

4 - 37ENGCYLINDER AND PISTONf. If out of specification, replace the cylinder,and the piston and piston rings as a set. ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲

4 - 38ENGCYLINDER AND PISTON3. Measure: • piston ring end gap Out of specification → Replace the pistonring.NOTE:_ The oil ring expander spacer’s end

4 - 39ENGCYLINDER AND PISTON2. Measure: • piston pin outside diameter a Out of specification → Replace the pistonpin.3. Measure:• piston pin bore insi

4 - 40ENGCYLINDER AND PISTONEBS00252INSTALLING THE PISTON1. Install: • piston rings (onto the piston)NOTE:_ • Be sure to install the piston rings so t

4 - 41ENGCYLINDER AND PISTON4. Lubricate: • piston • piston rings • cylinderNOTE:_ Apply a liberal coating of engine oil. EBS00253INSTALLING THE CYLIN

CHAPTER 9TROUBLESHOOTINGSTARTING FAILURE/HARD STARTING...9-1FUEL SYSTEM...

4 - 42ENGA.C. MAGNETOEBS00256A.C. MAGNETOT R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..16 Nm (1.6 m • kg, 11 ft • Ib)T R..65 Nm (6.5 m • kg, 47 ft • Ib)T R.

4 - 43ENGA.C. MAGNETOT R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..16 Nm (1.6 m • kg, 11 ft • Ib)T R..65 Nm (6.5 m • kg, 47 ft • Ib)T R..10 Nm (1.0 m • kg,

4 - 44ENGA.C. MAGNETOEBS00259REMOVING THE A.C. MAGNETO ROTOR1. Remove: • A.C. magneto coverNOTE:_ Loosen each bolt 1/4 of a turn at a time, instages a

4 - 45ENGA.C. MAGNETOEBS00263CHECKING THE STARTER CLUTCH1. Check: • starter one-way clutch 1 Cracks/damage → Replace. • bolts 2 Loose → Replace with a

4 - 46ENGA.C. MAGNETOCHECKING THE TORQUE LIMITER1. Check: • torque limiterDamage/wear → Replace.EBS00268INSTALLING THE A.C. MAGNETO ROTOR1. Install: •

4 - 47ENGA.C. MAGNETO4. Tighten: • A.C. magneto rotor nut 1 NOTE:_ • While holding the A.C. magneto rotor 2 withthe sheave holder 3, tighten the A.C.

4 - 48ENGCLUTCHEBS00291CLUTCHOrder Job/Part Q’ty RemarksRemoving the clutchRemove the parts in the order listed.Engine oil Drain.Clutch cable Refer t

4 - 49ENGCLUTCHOrder Job/Part Q’ty Remarks11 Push rod 2 112 Friction plate 1 7Refer to “INSTALLING THE CLUTCH”.13 Clutch plate 714 Friction plate 2 11

4 - 50ENGCLUTCHEBS00297REMOVING THE CLUTCH1. Remove: • clutch cover 1NOTE:_ Loosen each bolt 1/4 of a turn at a time, instages and in a crisscross pat

4 - 51ENGCLUTCHEBS00301CHECKING THE CLUTCH PLATESThe following procedure applies to all of theclutch plates.1. Check: • clutch plate Damage → Replace

1 - 1GENINFOMACHINE IDENTIFICATIONEBS00009GENERAL INFORMATION MACHINE IDENTIFICATIONEBS00010VEHICLE IDENTIFICATION NUMBERThe vehicle identification nu

4 - 52ENGCLUTCHEBS00304CHECKING THE CLUTCH BOSS1. Check: • clutch boss splines Damage/pitting/wear → Replace the clutchboss.NOTE:_ Pitting on the clut

4 - 53ENGCLUTCHEBS00311INSTALLING THE CLUTCH 1. Install: • push lever NOTE:_ Align the punch mark a on the push lever withthe punch mark b on the push

4 - 54ENGCLUTCH6. Install: • clutch cover 1 NOTE:_ Tighten the bolts in stages, using a crisscrosspattern. T R..10 Nm (1.0 m · kg, 7.2 ft · lb)7. Inst

4 - 55ENGBALANCERBALANCEROrder Job/Part Q’ty RemarksRemoving the balancerRemove the parts in the order listed.Clutch housing Refer to “CLUTCH”.Right c

4 - 56ENGBALANCERREMOVING THE BALANCER DRIVE GEAR AND BALANCER DRIVEN GEAR1. Straighten the lock washer tab.2. Loosen:• primary drive gear nut 1 • bal

4 - 57ENGBALANCERINSTALLING THE BALANCER DRIVE GEAR AND BALANCER DRIVEN GEAR1. Install:• balancer driven gear 1 NOTE:Install the balancer driven gear

4 - 58ENGOIL PUMPEBS00315OIL PUMPOrder Job/Part Q’ty RemarksRemoving the oil pumpRemove the parts in the order listed.Clutch housing Refer to “CLUTCH”

4 - 59ENGOIL PUMPOrder Job/Part Q’ty Remarks9Pin 110 Oil pump housing cover 111 Outer rotor 1 112 Inner rotor 1 113 Pin 114 Washer 115 Oil pump driven

4 - 60ENGOIL PUMPEBS00317CHECKING THE OIL PUMP 1. Check: • oil pump drive gear• oil pump driven gear • oil pump housing • oil pump housing cover Crack

4 - 61ENGSHIFT SHAFTSHIFT SHAFTOrder Job/Part Q’ty RemarksRemoving the shift shaftRemove the parts in the order listed.Clutch Refer to “CLUTCH”.Oil pu

1 - 2GENINFOIMPORTANT INFORMATIONEBS00013IMPORTANT INFORMATIONPREPARATION FOR REMOVAL AND DISASSEMBLY1. Before removal and disassembly remove alldirt,

4 - 62ENGSHIFT SHAFTOrder Job/Part Q’ty Remarks11 Stopper lever 1Refer to “INSTALLING THE SHIFTLEVER”.12 Stopper lever spring 113 Shift drum segment 1

4 - 63ENGSHIFT SHAFTEBS01018CHECKING THE SHIFT SHAFT1. Check: • shift shaft 1 Bends/damage/wear → Replace. • shift shaft spring 2 Damage/wear → Replac

4 - 64ENGSHIFT SHAFT2. Install:• stopper lever spring 1 • stopper lever 2NOTE:Align the stopper lever roller with a slot on theshift drum segment.12T

4 - 65ENGCRANKCASEEBS00320CRANKCASEOrder Job/Part Q’ty RemarksSeparating the crankcaseRemove the parts in the order listed. Engine assembly Refer to “

4 - 66ENGCRANKCASEOrder Job/Part Q’ty Remarks5 Circlip/spacer 1/16 Oil delivery pipe 2 17 Right crankcase 1Refer to “SEPARATING THE CRANK-CASE”.8 Left

4 - 67ENGCRANKCASEEBS00321OIL SEAL AND BEARINGOrder Job/Part Q’ty RemarksRemoving the crankcase bearingsRemove the parts in the order listed.Crankshaf

4 - 68ENGCRANKCASEEBS00332SEPARATING THE CRANKCASE 1. Separate: • right crankcase • left crankcase▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Remove

4 - 69ENGCRANKCASE2. Check: • oil delivery pipe 2Cracks/damage → Replace. • oil delivery pipe holes 1Clogged → Blow out with compressed air.EBS00335CH

4 - 70ENGEBS00342ASSEMBLING THE CRANKCASE 1. Install:• bearing• bearing retainer• bolt (bearing retainer)• screw [bearing retainer (crankshaft)] 1 • s

4 - 71ENGCRANKCASE4. Fit the right crankcase onto the left crank-case. Tap lightly on the case with a softhammer.CAUTION:_ Before installing and torqu

1 - 3GENINFOIMPORTANT INFORMATIONEBS00016LOCK WASHERS/PLATES AND COTTER PINSAfter removal, replace all lock washers/plates1 and cotter pins. After the

4 - 72ENGCRANKSHAFT1Order Job/Part Q’ty RemarksRemoving the crankshaftRemove the parts in the order listed.Crankcase Separate.Refer to “CRANKCASE”.1 C

4 - 73ENGEBS00337REMOVING THE CRANKSHAFT 1. Remove: • crankshaft 1Use a crankcase separating tool 2.Crankcase separating tool P/N. YU-01135-A, 90890-0

4 - 74ENGINSTALLING THE CRANKSHAFT1. Install: • crankshaft 1NOTE:_ Hold the connecting rod at the Top Dead Cen-ter (TDC) with one hand while turning t

4 - 75ENGTRANSMISSIONEBS00345TRANSMISSION7241365EEEEEEOrder Job/Part Q’ty RemarksRemoving the transmissionRemove the parts in the order listed.Crankca

4 - 76ENGTRANSMISSIONEBS00347MAIN AXLEOrder Job/Part Q’ty RemarksDisassembling the main axleRemove the parts in the order listed.12nd pinion gear 1 Re

4 - 77ENGTRANSMISSIONEBS00348DRIVE AXLEOrder Job/Part Q’ty RemarksDisassembling the drive axleRemove the parts in the order listed. Crankcase Refer to

4 - 78ENGTRANSMISSIONEBS00350CHECKING THE SHIFT FORKSThe following procedure applies to all of theshift forks.1. Check: • shift fork cam follower 1 •

4 - 79ENGTRANSMISSION3. Check: • transmission gear engagement (each pinion gear to its respective wheelgear) Incorrect → Reassemble the transmissiona

4 - 80ENGTRANSMISSIONEBS00356INSTALLING THE TRANSMISSION 1. Install: • shift fork “L” 1 (to drive axle)• shift fork “C” 2 (to main axle)• shift fork “

5 - 1COOLRADIATOREBS00125COOLING SYSTEMRADIATOR9210171434168151311(2)6512T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..9 Nm (0.9 m • kg, 6.5 ft • Ib)T R..28

1 - 4GENINFOIMPORTANT INFORMATIONEBS00019CHECKING THE CONNECTIONSCheck the leads, couplers, and connectors forstains, rust, moisture, etc.1. Disconnec

5 - 2COOLRADIATOR9210171434168151311(2)6512T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..9 Nm (0.9 m • kg, 6.5 ft • Ib)T R..28 Nm (2.8 m • kg, 20 ft • Ib)T

5 - 3COOLRADIATOREBS00127CHECKING THE RADIATOR1. Check: • radiator fins Obstruction → Clean. Apply compressed air to the rear of the radi-ator. Damage

5 - 4COOLRADIATOREBS00128INSTALLING THE RADIATOR1. Fill: • cooling system (with the specified amount of the recom-mended coolant) Refer to “CHANGING T

5 - 5COOLWATER PUMPEBS00134WATER PUMPOrder Job/Part Q’ty RemarksRemoving the water pumpRemove the parts in the order listed.Engine oil Drain.Coolant D

5 - 6COOLWATER PUMPOrder Job/Part Q’ty Remarks8 Oil hose 1 19 Right crankcase cover 110 Gasket 111 Impeller 112 Washer 113 Impeller shaft 114 Oil seal

5 - 7COOLWATER PUMPEBS00139CHECKING THE WATER PUMP1. Check: • water pump housing 1 • impeller 2 • impeller shaft 3Cracks/damage/wear → Replace.2. Chec

6 - 1CARBCARBURETOREBS00141CARBURETORCARBURETOR479712538T R..3 Nm (0.3 m • kg, 2.2 ft • Ib)T R..4 Nm (0.4 m • kg, 2.9 ft • Ib)T R..3 Nm (0.3 m • kg, 2

6 - 2CARBCARBURETOREBS00144Order Job/Part Q’ty RemarksDisassembling the carburetorRemove the parts in the order listed.1Drain hose 12Air vent hose 23T

6 - 3CARBOrder Job/Part Q’ty RemarksA Needle holder 1B Jet needle 1C Cover/spring 1/1D Pilot air diaphragm 1E Cover/spring 1/1F Accelerator pump diaph

6 - 4CARBOrder Job/Part Q’ty RemarksK Needle valve 1L Main jet 1M Needle jet 1N Spacer 1O Pilot jet 1P Starter jet 1Q Pilot air jet 1For assembly, rev

1 - 5GENINFOSPECIAL TOOLSEBS00021SPECIAL TOOLSThe following special tools are necessary for complete and accurate tune-up and assembly. Useonly the ap

6 - 5CARBCARBURETOREBS00146DISASSEMBLING THE CARBURETOR NOTE:_ Before disassembling the carburetor, makesure to note the number of times the pilotscre

6 - 6CARBCARBURETOR4. Check: • throttle valve 1 • throttle valve plate 2Scratches/wear/damage → Replace. 215. Check:• accelerator pump diaphragm 1 • p

6 - 7CARBCARBURETOREBS00150ASSEMBLING THE CARBURETORCAUTION:_ Before reassembling, wash all of the partsin a clean petroleum based solvent. 1. Install

6 - 8CARBCARBURETORADJUSTING THE ACCELERATOR PUMP TIMING1. Adjust:• accelerator pump timing▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼NOTE:Insert a ro

6 - 9CARBCARBURETORINSTALLING THE CARBURETOR1. Install:• carburetorNOTE:Align the projection a on the carburetor withthe slot b in the carburetor join

6 - 10CARBCARBURETOR2. Adjust:• throttle position sensor angle▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Loosen the throttle position sensor screw1

7 - 1CHASFRONT AND REAR WHEELSEBS00378CHASSIS FRONT AND REAR WHEELS FRONT WHEELSOrder Job/Part Q’ty RemarksRemoving the front wheelsRemove the parts i

7 - 2CHASOrder Job/Part Q’ty Remarks5 Brake caliper assembly 1NOTE:_ Do not squeeze the brake lever when thebrake caliper is off of the brake discs as

7 - 3CHASREAR WHEELSOrder Job/Part Q’ty RemarksRemoving the rear wheelsRemove the parts in the order listed.Place the machine on a level surface.WARNI

7 - 4CHASEBS00383CHECKING THE WHEELS 1. Check: • wheels 2. Measure: • wheel runout Over the specified limit → Replace thewheel or check the wheel bear

1 - 6GENINFOSPECIAL TOOLS90890-01352YU-33984Radiator cap tester adapterThis tool is used to check the cooling sys-tem.90890-01327YM-01327Damper rod ho

7 - 5CHAS2. Check: • wheel bearings Wheel hub play/wheel turns roughly →Replace. ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Clean wheel hub exterio

7 - 6CHASINSTALLING THE FRONT WHEEL HUB BEARINGS1. Install: • bearings 1NOTE:Face the oil seal side of the bearing inward.INSTALLING THE FRONT BRAKE D

7 - 7CHASEBS00390INSTALLING THE WHEEL HUBS 1. Install: • front axle nuts 1 • rear axle nuts 1 • cotter pins 2 NOTE:_ Do not loosen the axle nut after

7 - 8CHASREAR AXLE AND REAR AXLE HUBEBS00382REAR AXLE AND REAR AXLE HUBOrder Job/Part Q’ty RemarksRemoving the rear axle and rear axlehubRemove the pa

7 - 9CHASOrder Job/Part Q’ty Remarks7 Brake disc/brake disc bracket 1/1Refer to “REMOVING THE REARAXLE”.8 Rear axle 19 Circlip 110 Driven sprocket/spr

7 - 10CHASREAR AXLE AND REAR AXLE HUBEBS00393REMOVING THE REAR AXLE 1. Place the machine on a level surface. 2. Remove:• bolts3. Loosen: • nut 1 NOTE:

7 - 11CHASREAR AXLE AND REAR AXLE HUB8. Remove: • rear axle 1 (with driven sprocket)CAUTION:_ • Never directly tap the axle end with ahammer, since th

7 - 12CHASREAR AXLE AND REAR AXLE HUBINSTALLING THE DRIVEN SPROCKET1. Install: • driven sprocket NOTE:Make sure that the blunt-edged corner a ofthe dr

7 - 13CHASEBS00400FRONT AND REAR BRAKESFRONT BRAKE PADST R..28 Nm (2.8 m • kg, 20 ft • Ib)T R..18 Nm (1.8 m • kg, 13 ft • Ib)LT312Order Job/Part Q’ty

7 - 14CHASEBS00401REAR BRAKE PADS114532NewT R..18 Nm (1.8 m • kg, 13 ft • Ib)T R..31 Nm (3.1 m • kg, 22 ft • Ib)Order Job/Part Q’ty RemarksRemoving th

1 - 7GENINFOSPECIAL TOOLSCompressor90890-04019YM-04019Attachment90890-04114YM-04114Valve spring compressorValve spring compressor attachmentThis tool

7 - 15CHASEBS00402CAUTION:_ Disc brake components rarely require dis-assembly. DO NOT: • disassemble components unless abso-lutely necessary; • use so

7 - 16CHAS2. Install: • brake pads • brake pad springNOTE:_ Always install new brake pads and brake padspring as a set. ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼

7 - 17CHASEBS00405REPLACING THE REAR BRAKE PADSNOTE:_ It is not necessary to disassemble the brakecaliper and brake hose to replace the brakepads. 1.

7 - 18CHASf. Bend the lock washer tabs along a flat sideof the bolts.▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲3. Check: • brake fluid level Refer to

7 - 19CHASEBS00407FRONT BRAKE MASTER CYLINDEROrder Job/Part Q’ty RemarksRemoving the front brake master cylinderRemove the parts in the order listed.B

7 - 20CHASEBS00409Order Job/Part Q’ty RemarksDisassembling the front brake mas-ter cylinderRemove the parts in the order listed.1Dust boot 1Refer to “

7 - 21CHASEBS00410REAR BRAKE MASTER CYLINDEROrder Job/Part Q’ty RemarksRemoving the rear brake master cyl-inderRemove the parts in the order listed.Ri

7 - 22CHASOrder Job/Part Q’ty Remarks7 Union bolt 1Refer to “INSTALLINGTHE REAR BRAKE MAS-TER CYLINDER”.8 Copper washer 29 Brake hose 1 Disconnect.10

7 - 23CHASEBS00411Order Job/Part Q’ty RemarksDisassembling the rear brake mas-ter cylinderRemove the parts in the order listed.1Hose joint 12Brake mas

7 - 24CHASEBS00413CHECKING THE MASTER CYLINDERS1. Check: • brake master cylinder 1 Wear/scratches → Replace the brake mas-ter cylinder assembly. • bra

1 - 8GENINFOSPECIAL TOOLSYM-37134Axle nut wrench (46 mm)This tool is needed to loosen or tighten the rear axle nut.90890-06754Ignition checkerThis ins

7 - 25CHASEBS00415ASSEMBLING THE FRONT BRAKE MASTER CYLINDERWARNING_ • All internal brake components should becleaned and lubricated with new brakeflu

7 - 26CHASEBS00418INSTALLING THE FRONT BRAKE MASTER CYLINDER1. Install: • brake master cylinder 1 NOTE:_ • The “UP” mark on the brake master cylinderb

7 - 27CHASWARNING_ • Use only the designated quality brakefluid: other brake fluids may deterioratethe rubber seals, causing leakage andpoor brake per

7 - 28CHAS2. Install:• brake fluid reservoir hose 1NOTE:Install the brake fluid reservoir hose with thewhite paint mark a facing up as shown.3. Fill:

7 - 29CHASEBS00421FRONT BRAKE CALIPERS12635T R..27 Nm (2.7 m • kg, 19 ft • Ib)NewT R..18 Nm (1.8 m • kg, 13 ft • Ib)LT4T R..28 Nm (2.8 m • kg, 20 ft •

7 - 30CHASEBS00423NewNewLT87654123LST R..18 Nm (1.8 m • kg, 13 ft • Ib)T R..6 Nm (0.6 m • kg, 4.3 ft • Ib)Order Job/Part Q’ty RemarksDisassembling the

7 - 31CHASEBS00424REAR BRAKE CALIPEROrder Job/Part Q’ty RemarksRemoving the rear brake caliperRemove the parts in the order listed.Brake fluid Drain.1

7 - 32CHASEBS00425Order Job/Part Q’ty RemarksDisassembling the rear brake cali-perRemove the parts in the order listed.1Adjusting bolt 12Locknut 13Par

7 - 33CHASOrder Job/Part Q’ty RemarksA Brake pad holding bolt 2B Lock washer 1C Brake pad/pad shim 2/1D Brake pad spring 1E Retaining bolt 1F Caliper

7 - 34CHASREMOVING THE PARKING BRAKE CABLE 1. Loosen:• nut• adjusting bolt2. Disconnect:• parking brake cable (from parking brake lever)3. Disconnect:

2 - 1SPECGENERAL SPECIFICATIONSEBS01001SPECIFICATIONSGENERAL SPECIFICATIONSItem StandardModel code5TG1DimensionsOverall length 1,840 mm (72.4 in)Overa

7 - 35CHASEBS00429CHECKING THE FRONT AND REAR BRAKE CALIPERSWARNING_ All internal brake components should becleaned in new brake fluid only. Do not us

7 - 36CHASEBS00431ASSEMBLING THE FRONT BRAKE CALIPERSThe following procedure applies to both of thefront brake calipers.WARNING_ • All internal brake

7 - 37CHAS2. Install: • brake caliper piston 13. Install: • lock washer 1• brake pad holding bolts 2 4. Bend the lock washer tabs along a flat sideof

7 - 38CHASEBS00434INSTALLING THE FRONT BRAKE CALIPERSThe following procedure applies to both of thefront brake calipers.1. Install: • brake caliper as

7 - 39CHAS3. Air bleed: • brake system Refer to “BLEEDING THE HYDRAULICBRAKE SYSTEM” in chapter 3.4. Check: • brake fluid level Brake fluid level is b

7 - 40CHASCAUTION:_ Brake fluid may damage painted surfacesor plastic parts. Always clean up spilledbrake fluid immediately. WARNING_ • Use only the d

7 - 41CHASSTEERING SYSTEMEBS00444STEERING SYSTEMHANDLEBAR789911102121213451161352T R..23 Nm (2.3 m • kg, 17 ft • Ib)T R..7 Nm (0.7 m • kg, 5.1 ft • Ib

7 - 42CHASSTEERING SYSTEM789911102121213451161352T R..23 Nm (2.3 m • kg, 17 ft • Ib)T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..7 Nm (0.7 m • kg, 5.1 ft •

7 - 43CHASSTEERING SYSTEMEBS00446REMOVING THE FRONT BRAKE LIGHT SWITCH AND CLUTCH SWITCH1. Remove: • front brake light switch 1 • clutch switchNOTE:_

7 - 44CHASSTEERING SYSTEMEBS00449INSTALLING THE HANDLEBAR1. Install: • handlebar • handlebar holders NOTE:_ • Install the handlebar within 3.3° from t

2 - 2SPECGENERAL SPECIFICATIONSCarburetorType/quantity 5TG1 00 × 1Manufacturer KEIHINSpark plugType/manufacturer CR8E/NGKSpark plug gap 0.7 ~ 0.8 mm (

7 - 45CHASEBS00452INSTALLING THE CLUTCH LEVER1. Install: • handlebar switch 1 • clutch lever • clutch lever bracket 2NOTE:_ Install the clutch lever b

7 - 46CHASSTEERING SYSTEMEBS00454STEERING STEMOrder Job/Part Q’ty RemarksRemoving the steering stemRemove the parts in the order listed.Fuel tank cove

7 - 47CHASSTEERING SYSTEMOrder Job/Part Q’ty Remarks9 Bearing retainer 1 Refer to “REMOVING THE BEARINGRETAINER” and “INSTALLING THEBEARING RETAINER

7 - 48CHASSTEERING SYSTEMEBS00455REMOVING THE BEARING RETAINER1. Remove: • bearing retainerDamper rod holder (30 mm)P/N. YM-01327, 90890-01327EBS00456

7 - 49CHASSTEERING SYSTEMEBS00459INSTALLING THE LOCK WASHER1. Install: • lock washer• bolts 2. Bend the lock washer tab along a flat side ofthe bolt.N

7 - 50CHASSTEERING SYSTEMEBS00460TIE-RODS AND STEERING KNUCKLESOrder Job/Part Q’ty RemarksRemoving the tie-rods and steering knucklesRemove the parts

7 - 51CHASSTEERING SYSTEMEBS00461REMOVING THE STEERING KNUCKLES1. Remove: • steering knuckles 1NOTE:_ Use a general puller to separate the ball joint2

7 - 52CHASFRONT ARMS AND FRONT SHOCK ABSORBERASSEMBLIESEBS00468FRONT ARMS AND FRONT SHOCK ABSORBER ASSEMBLIESOrder Job/Part Q’ty RemarksRemoving the f

7 - 53CHASFRONT ARMS AND FRONT SHOCK ABSORBERASSEMBLIESOrder Job/Part Q’ty Remarks8 Nut/bolt 2/2Refer to “REMOVING THE FRONTARMS” and “INSTALLING THE

7 - 54CHASFRONT ARMS AND FRONT SHOCK ABSORBERASSEMBLIESEBS00469REMOVING THE FRONT ARMS1. Check: • front arm free play▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼

2 - 3SPECGENERAL SPECIFICATIONSBrakeFront brake type Dual disc brakeoperation Right hand operationRear brake type Single disc brakeoperation Right foo

7 - 55CHASFRONT ARMS AND FRONT SHOCK ABSORBERASSEMBLIES• Do not deform or damage the front shockabsorber or gas cylinder in any way. If thefront shock

7 - 56CHASFRONT ARMS AND FRONT SHOCK ABSORBERASSEMBLIESEBS00472CHECKING THE BALL JOINTSThe following procedure applies to both of thefront arm ball jo

7 - 57CHASFRONT ARMS AND FRONT SHOCK ABSORBERASSEMBLIESf. Attach the assembled ball joint remover/installer, new ball joint (with rubber boot andretai

7 - 58CHASREAR SHOCK ABSORBER AND RELAY ARMEBS00484REAR SHOCK ABSORBER AND RELAY ARM7711043422121211099856NewNew1314141311LSLSNewNewNewNewLSLST R..55

7 - 59CHASREAR SHOCK ABSORBER AND RELAY ARM7711043422121211099856NewNew1314141311LSLSNewNewNewNewLSLST R..55 Nm (5.5 m • kg, 40 ft • Ib)T R..55 Nm (5.

7 - 60CHASREAR SHOCK ABSORBER AND RELAY ARMEBS00485HANDLING THE REAR SHOCK ABSORBER AND GAS CYLINDERWARNING_ This rear shock absorber and gas cylinder

7 - 61CHASREAR SHOCK ABSORBER AND RELAY ARMEBS00487REMOVING THE REAR SHOCK ABSORBER1. Remove: • relay arm-to-rear shock absorber lower bolt• rear shoc

7 - 62CHASREAR SHOCK ABSORBER AND RELAY ARMEBS00490INSTALLING THE RELAY ARM AND CONNECTING ARM1. Install: • bearing 1 (to connecting arm)2. Install: •

7 - 63CHASSWINGARM AND DRIVE CHAINEBS00492SWINGARM AND DRIVE CHAINOrder Job/Part Q’ty RemarksRemoving the swingarm and drive chainRemove the parts in

7 - 64CHASSWINGARM AND DRIVE CHAINOrder Job/Part Q’ty Remarks8 Drive chain guide 2 1Refer to “INSTALLING THE DRIVE SPROCKET”.9Nut 110 Lock washer 111

LIT-11616-17-11 5TG-28197-10YFZ450SSERVICE MANUAL

2 - 4SPECENGINE SPECIFICATIONSEBS01002ENGINE SPECIFICATIONSItem Standard LimitCylinder headWarp limit ---- 0.05 mm (0.002 in)CylinderBore size 95.00 ~

7 - 65CHASSWINGARM AND DRIVE CHAINEBS00493NOTE:Before removing the drive chain and thesprockets, measure the drive chain slack anda 15-link section of

7 - 66CHASSWINGARM AND DRIVE CHAIN2. Check: • pivot shaft Roll the axle on a flat surface. Bends → Replace.WARNING_ Do not attempt to straighten a ben

7 - 67CHASSWINGARM AND DRIVE CHAINEBS00496CHECKING THE DRIVE CHAIN1. Measure: • 15-link section a of the drive chain Out of specification → Replace th

7 - 68CHASSWINGARM AND DRIVE CHAIN4. Check: • O-rings 1 Damage → Replace the drive chain. • drive chain rollers 2 Damage/wear → Replace the drive chai

7 - 69CHASSWINGARM AND DRIVE CHAINEBS00498INSTALLING THE DRIVE SPROCKET1. Install: • drive sprocket 1 • lock washer 2• nut 3 2. Bend the lock washer t

8 - 1– +ELECELECTRICAL COMPONENTSEBS00500ELECTRICALELECTRICAL COMPONENTS1Main switch 2Throttle switch3Front brake light switch 4Indicator light5Clutch

8 - 2– +ELECCHECKING SWITCH CONTINUITYEBS01028CHECKING SWITCH CONTINUITYCheck each switch for continuity with thepocket tester. If the continuity read

8 - 3– +ELECCHECKING SWITCH CONTINUITY

8 - 4– +ELECCHECKING THE SWITCHESEBS01029CHECKING THE SWITCHESCheck each switch for damage or wear, proper connections, and also for continuity betwee

8 - 5– +ELECCHECKING THE SWITCHES1 Light switch 2 Engine stop switch 3 Start switch 4 Main switch 5 Front brake light switch 6 Throttle switch7 Clutch

2 - 5SPECENGINE SPECIFICATIONSValve, valve seat, valve guideValve clearance (cold) IN 0.10 ~ 0.15 mm (0.0039 ~ 0.0059 in) ----EX 0.20 ~ 0.25 mm (0.007

8 - 6– +ELECCHECKING THE BULBS AND BULB SOCKETSEBS01030CHECKING THE BULBS AND BULB SOCKETSCheck each bulb and bulb socket for damageor wear, proper co

8 - 7– +ELECCHECKING THE BULBS AND BULB SOCKETSWARNING_ Since the headlight bulb gets extremelyhot, keep flammable products and yourhands away from th

8 - 8– +ELECCHECKING THE CONDITION OF THE BULB SOCKETSThe following procedure applies to all of thebulb sockets. 1. Check: • bulb socket (for continui

8 - 9– +ELECIGNITION SYSTEMEBS00503IGNITION SYSTEMCIRCUIT DIAGRAM(BROWN)BW/L(BLACK)LR/WYLB/LLYBY(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)WRW/BY/RW/B

8 - 10– +ELECTHROTTLE OVERRIDE SYSTEM (T.O.R.S.) OPERATIONThis model is equipped with a throttle overridesystem as a safety device that operatesaccord

8 - 11– +ELECIGNITION SYSTEMEBS01045TROUBLESHOOTINGCheck: 1. fuse 2. battery 3. spark plug4. ignition spark gap 5. ignition coil resistance 6. main sw

8 - 12– +ELECIGNITION SYSTEMEBS01034NOYESEBS01038YESNO4. Ignition spark gap • Disconnect the ignition coil from the sparkplug. • Connect the dynamic s

8 - 13– +ELECIGNITION SYSTEMEBS01041YESNOEBS01042YESNOYESNOYESNOEBS01040YESNOEBS01047YESNO6. Main switch • Check the main switch for continuity. Refer

8 - 14– +ELECCHECKING THE THROTTLE OVERRIDE SYSTEMWARNING• Make sure that the parking brake isapplied.• Make sure that the transmission is in neu-tral

8 - 15–+ELECIGNITION SYSTEM5. Install:• throttle lever cover• carburetor switch/throttle stop screwassembly cover• throttle position sensorRefer to “C

2 - 6SPECENGINE SPECIFICATIONSValve springFree length IN 37.03 mm (1.46 in) 35.17 mm (1.38 in)EX 37.68 mm (1.48 in) 35.79 mm (1.41 in)Set length (valv

8 - 16– +ELECELECTRIC STARTING SYSTEMEBS00506ELECTRIC STARTING SYSTEMCIRCUIT DIAGRAM(BROWN)BW/L(BLACK)LR/WYLB/LLYBY(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)

8 - 17– +ELECELECTRIC STARTING SYSTEMEBS00508STARTING CIRCUIT CUT-OFF SYSTEM OPERATIONThe starting circuit on this model consists ofthe starter motor,

8 - 18– +ELECELECTRIC STARTING SYSTEMEBS01050TROUBLESHOOTINGCheck: 1. fuse 2. battery 3. starter motor 4. starting circuit cut-off relay 5. starting c

8 - 19– +ELECELECTRIC STARTING SYSTEMEBS01052YESNOEBS01053YESNO4. Starting circuit cut-off relay • Remove the starting circuit cut-off relayfrom the w

8 - 20– +ELECELECTRIC STARTING SYSTEMEBS01054YESNOEBS01041YESNOEBS01042YESNOEBS01046YESNOEBS01056YESNOEBS01057YESNO6. Starter relay • Disconnect the s

8 - 21– +ELECELECTRIC STARTING SYSTEMEBS01059YESNO12.Wiring • Check the entire starting system’s wiring. Refer to “CIRCUIT DIAGRAM”. • Is the starting

8 - 22– +ELECSTARTER MOTOREBS01061STARTER MOTOR234T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)NewNewNewT R..18 Nm (1.8 m •

8 - 23– +ELECSTARTER MOTOREBS010625786012439NewNewNewNewT R..7 Nm (0.7 m • kg, 5.1 ft • Ib)LSOrder Job/Part Q’ty RemarksDisassembling the starter moto

8 - 24– +ELECSTARTER MOTOREBS01064CHECKING THE STARTER MOTOR1. Check: • commutator Dirt → Clean with 600-grit sandpaper.2. Measure: • commutator diame

8 - 25– +ELECSTARTER MOTOR5. Measure: • brush length a Out of specification → Replace the brushesas a set.6. Measure: • brush spring force Out of spec

2 - 7SPECENGINE SPECIFICATIONSPiston ringsTop ringType Barrel ----Dimensions (B × T) 1.2 × 3.5 mm (0.047 × 0.138 in) ----End gap (installed) 0.20 ~ 0.

8 - 26– +ELECCHARGING SYSTEMEBS00516CHARGING SYSTEMCIRCUIT DIAGRAM(BROWN)BW/LY(BLACK)(BLACK)(BLACK)(GRAY)(GRAY)(BLACK)(BLACK)(BLACK)WRW/BY/RW/B RBY/RW

8 - 27– +ELECCHARGING SYSTEMEBS01065TROUBLESHOOTINGCheck: 1. fuse 2. battery 3. charging voltage 4. charging coil resistance 5. wiring connections (of

8 - 28– +ELECCHARGING SYSTEMEBS01066NOYESEBS01100YESNOYESNO3. Charging voltage • Connect the engine tachometer to on tothe ignition coil. • Connect th

8 - 29– +ELECLIGHTING SYSTEMEBS00518LIGHTING SYSTEMCIRCUIT DIAGRAM(BROWN)BW/LY(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)WRW/BY/RW/B RBY/RWR RW(GRAY)(G

8 - 30– +ELECLIGHTING SYSTEMEBS01067TROUBLESHOOTINGCheck: 1. light switch 2. lighting coil resistance3. wiring connections (of the entire lighting sys

8 - 31– +ELECLIGHTING SYSTEMEBS01069YESNOEBS01070CHECKING THE LIGHTING SYSTEM1. The headlights fail to come on.YESNOYESNO3. Wiring • Check the entire

8 - 32– +ELECLIGHTING SYSTEM2. The tail/brake light fails to come on.YESNOYESNO1. Tail/brake light bulb and socket • Check the tail/brake light bulb a

8 - 33– +ELECSIGNAL SYSTEMEBS00521SIGNAL SYSTEMCIRCUIT DIAGRAM(BROWN)BW/L(BLACK)LR/WYLB/LLYBY(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)WRW/BY/RW/B RBY

8 - 34– +ELECSIGNAL SYSTEMEBS01073TROUBLESHOOTINGCheck: 1. fuse 2. battery 3. main switch 4. wiring connections (of the entire signaling system)NOTE:_

8 - 35– +ELECSIGNAL SYSTEMEBS01075CHECKING THE SIGNALING SYSTEMEBS010761. The tail/brake light fails to come on.YESNOYESNOYESNOEBS010772. The neutral

2 - 8SPECENGINE SPECIFICATIONSBalancerBalancer drive method Gear ----ClutchFriction plate 1 (inside dia.: 120 mm)Thickness 2.9 ~ 3.1 mm (0.114 ~ 0.122

8 - 36– +ELECSIGNAL SYSTEMYESNOYESNOEBS010833. The coolant temperature warning light doesnot come on when the start switch ispushed on, or if the cool

8 - 37– +ELECSIGNAL SYSTEMYESNO2. Thermo switch 2• Remove the thermo switch 2 from the radi-ator. • Connect the pocket tester (Ω × 1) to thethermo sw

8 - 38– +ELECSIGNAL SYSTEMYESNOYESNOYESNO3. Voltage • Connect the pocket tester (DC 20 V) to theindicator light connector (wire harnessside) as shown.

8 - 39– +ELECCOOLING SYSTEMEBS00532COOLING SYSTEMCIRCUIT DIAGRAM(GRAY)(GRAY)RBrBr/LBr/LR/WBrRR(BROWN)BW/L(BLACK)LR/W(BLACK)(BLACK)W/B RBY/R(GR(GRY/BB/

8 - 40– +ELECCOOLING SYSTEMEBS01085TROUBLESHOOTINGCheck: 1. fuse 2. battery 3. main switch 4. radiator fan motor 5. circuit breaker (fan motor)6. ther

8 - 41– +ELECCOOLING SYSTEMEBS01086YESNOYESNOEBS010884. Radiator fan motor • Disconnect the radiator fan motor couplerfrom the wire harness. • Connect

8 - 42– +ELECCOOLING SYSTEMYESNOEBS01090YESNOWARNING_ • Handle the thermo switch with specialcare. • Never subject the thermo switch tostrong shocks.

9 - 1TRBLSHTGSTARTING FAILURE/HARD STARTINGEBS00537TROUBLESHOOTINGNOTE:_ The following troubleshooting does not cover all the possible causes of troub

9 - 2TRBLSHTGSTARTING FAILURE/HARD STARTING/POOR IDLE SPEEDPERFORMANCE/POOR MEDIUM AND HIGH-SPEED PERFORMANCECOMPRESSION SYSTEMCylinder and cylinder h

9 - 3TRBLSHTGFAULTY GEAR SHIFTING/CLUTCH SLIPPING/DRAGGINGEBS00541FAULTY GEAR SHIFTINGHARD SHIFTINGRefer to “CLUTCH DRAGGING”.SHIFT PEDAL DOES NOT MOV

2 - 9SPECENGINE SPECIFICATIONSCarburetorI. D. mark 5TG1 00 ----Main jet (M.J) #158 ----Main air jet (M.A.J) ø1.0 ----Jet needle/clip position (J.N)

9 - 4TRBLSHTGOVERHEATING/FAULTY BRAKE/SHOCK ABSORBER MALFUNCTIONEBS00547OVERHEATINGOVERHEATINGIgnition system• Improper spark plug gap • Improper spar

9 - 5TRBLSHTGUNSTABLE HANDLING/LIGHTING SYSTEMEBS00552UNSTABLE HANDLINGUNSTABLE HANDLINGHandlebar• Improperly installed or bentSteering• Incorrect toe

YAMAHA MOTOR CO., LTD.2500 SHINGAI IWATA SHIZUOKA JAPANPRINTED IN U.S.A.

YFZ450S WIRING DIAGRAM(BROWN)BW/L(BLACK)LR/WYLB/LLYBY(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)(BLACK)WRW/BY/RW/B RBY/RWR RW(GRAY)(GRAY)RBrBr/LBr/LR/WBrRR(GR

2 - 10SPECENGINE SPECIFICATIONSLubrication chartOil tankCamshaftValve lifterPistonPiston pinCrank pinOil filterCylinder headTransmission gearsMain axl

2 - 11SPECENGINE SPECIFICATIONSCylinder head tightening sequence

2 - 12SPECCHASSIS SPECIFICATIONSEBS01003CHASSIS SPECIFICATIONSItem Standard LimitSteering systemSteering bearing type Ball and race bearing ----Front

2 - 13SPECCHASSIS SPECIFICATIONSFront disc brakeType Dual ----Disc outside diameter × thickness 161.0 × 3.5 mm (6.34 × 0.14 in) ----Pad thickness inne

EBS00001YFZ450S SERVICE MANUAL ©2003 by Yamaha Motor Corporation, U.S.A. First Edition, May 2003 All rights reserved. Any reproduction or unauthorized

2 - 14SPECELECTRICAL SPECIFICATIONSEBS01004ELECTRICAL SPECIFICATIONSItem Standard LimitVoltage12 V ----Ignition systemIgnition timing (B.T.D.C.) 7.5°/

2 - 15SPECELECTRICAL SPECIFICATIONSStarter relayModel/manufacturer 2768079-A/JIDECO ----Amperage rating 180 A ----Coil winding resistance 4.18 ~ 4.62

2 - 16SPECTIGHTENING TORQUESEBS01005TIGHTENING TORQUESENGINE TIGHTENING TORQUES Part to be tightened Part nameThreadsizeQ’tyTightening torqueRemarksNm

2 - 17SPECTIGHTENING TORQUESCylinder head water jacket Bolt M6 1 10 1.0 7.2Water pump housing cover Bolt M6 4 10 1.0 7.2Coolant reservoir Bolt M6 2 7

2 - 18SPECTIGHTENING TORQUESNOTE:*1: Tighten the cylinder head bolts to 30 Nm (3.0 m · kg, 22 ft · lb) in the proper tightening sequence,remove and re

2 - 19SPECTIGHTENING TORQUESEBS01006CHASSIS TIGHTENING TORQUES Part to be tightened Thread sizeTightening torqueRemarksNm m · kg ft · lbEngine stay an

2 - 20SPECTIGHTENING TORQUESFront brake master cylinder and brake lever M6 6 0.6 4.3Front brake master cylinder and brake hose M10 27 2.7 19Brake hose

2 - 21SPECHOW TO USE THE CONVERSION TABLE/GENERAL TIGHTENING TORQUE SPECIFICATIONSEBS00022HOW TO USE THE CONVERSION TABLEAll specification data in thi

2 - 22SPECLUBRICATION POINTS AND LUBRICANT TYPESEBS00024LUBRICATION POINTS AND LUBRICANT TYPESENGINELubrication point LubricantOil seal lipsLSO-ringsL

2 - 23SPECLUBRICATION POINTS AND LUBRICANT TYPESCrankcase mating surfacesSealant (Quick Gasket®)Yamaha bond No.1215Cylinder head and cylinder head cov

EBS00002NOTICEThis manual was produced by the Yamaha Motor Company primarily for use by Yamaha dealersand their qualified mechanics. It is not possibl

2 - 24SPECCOOLANT FLOW DIAGRAMSEBS00025COOLANT FLOW DIAGRAMS1Radiator inlet hose2Radiator3Radiator fan 4Radiator outlet hose5Water pump inlet pipe6Wat

2 - 25SPECCOOLANT FLOW DIAGRAMSÈ Install the radiator outlet hose with the white paint mark parallel to the ground as shown.É Install the radiator out

2 - 26SPECOIL FLOW DIAGRAMSEBS00026OIL FLOW DIAGRAMS1Intake camshaft2Exhaust camshaft3Oil filter element4Oil tank5Oil pipe 16Oil pipe 27Main axle8Driv

2 - 27SPECOIL FLOW DIAGRAMS1 Camshaft2 Oil filter element3 Crankshaft4 Main axle5 Drive axle6 Oil delivery pipe 27 Connecting rod7123456

2 - 28SPECCABLE ROUTINGEBS00028CABLE ROUTING1Parking brake cable2Clutch cable3Clutch switch lead4Handlebar switch lead5Front brake light switch lead6T

2 - 29SPECCABLE ROUTINGÈ Fasten the clutch switch lead and handlebar switch lead to the handlebar with the plastic band.É Fasten the front brake light

2 - 30SPECCABLE ROUTING1 Throttle cable2 Front brake hose3 Front brake light switch lead4 Throttle switch lead5 Clutch cable6 Parking brake cable7 Clu

2 - 31SPECCABLE ROUTINGÈ Pass the throttle cable through the cable guide.É Pass the throttle cable, leads (front brake lightswitch, throttle switch, c

2 - 32SPECCABLE ROUTINGÏ Slide the rubber cover over the couplers (frontbrake light switch, throttle switch, clutch switch,and handlebar switch) and f

2 - 33SPECCABLE ROUTING1 Indicator coupler2 Radiator fan motor coupler3 Thermo switch 24 Fuel tank breather hose5 Radiator fan motor lead6 Radiator fa

EBS00004HOW TO USE THIS MANUALMANUAL ORGANIZATIONThis manual consists of chapters for the main categories of subjects. (See “symbols”)1st title 1: Thi

2 - 34SPECCABLE ROUTINGÈ Route the neutral switch lead, A.C. magnetolead, and radiator fan motor lead under theframe.É Fasten the wire harness, thermo

2 - 35SPECCABLE ROUTINGÑ Fasten the negative battery lead and startermotor lead with the plastic band and then facethe end of the plastic band inward.

2 - 36SPECCABLE ROUTINGÙ When installing the fuel tank cover, do not pinchthe front brake hose, throttle cable, front brakelight switch lead, or throt

2 - 37SPECCABLE ROUTING1 Wire harness2 Air filter case breather hose3 Cylinder head breather hose4 Coolant reservoir breather hose5 Coolant reservoir

2 - 38SPECCABLE ROUTINGË Install the coolant reservoir breather hose with-out twisting the hose.Ì Fasten the coolant reservoir hose and the cool-ant r

2 - 39SPECCABLE ROUTINGÒ Route the carburetor drain hose between theframe and connecting arm and let it hang freelyunder the vehicle.ACCDDEEGGAE-EBBC-

2 - 40SPECCABLE ROUTING1 Rear brake light switch lead2 Throttle cable3 Clutch cable4 Coolant reservoir hose5 Oil tank breather hose6 Thermo switch 1 l

2 - 41SPECCABLE ROUTING1 Rear brake hose2 Parking brake cable3 Rear brake light switch4 Rear brake light switch leadÈ Install the lead protector of th

2 - 42SPECCABLE ROUTING1 Rectifier/regulator2 Headlight lead (right)3 Main switch lead4 Thermo switch 1 lead5 Coolant reservoir hose6 Oil tank breathe

2 - 43SPECCABLE ROUTINGÊ Route the main switch lead under the frame andconnect.Ë To thermo switch 1Ì To main switchÍ To radiatorÎ Route the rear brake

EBS00006SYMBOLSThe following symbols are not relevant toevery machine. Symbols 1 to 9 indicate the subject of eachchapter.1General information 2Specif

2 - 44SPECCABLE ROUTING1 Starter relay2 Battery positive lead3 Tail/brake light lead4 Starter motor lead5 Starting circuit cut-off relay6 Earth lead7

2 - 45SPECCABLE ROUTINGÌ Fasten the coolant reservoir hose and the cylin-der head breather hose to the frame with theplastic beaded tie at its loosest

3 - 1CHKADJINTRODUCTION/PERIODIC MAINTENANCE/LUBRICATIONEBS00029PERIODIC CHECKS AND ADJUSTMENTSINTRODUCTIONThis chapter includes all information neces

3 - 2CHKADJPERIODIC MAINTENANCE/LUBRICATION* Since these items require special tools, data and technical skills, have a Yamaha dealer perform the serv

3 - 3CHKADJSEAT, FENDERS AND FUEL TANKEBS00033SEAT, FENDERS AND FUEL TANKSEAT, FUEL TANK COVER AND SIDE COVERS1243T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T

3 - 4CHKADJSEAT, FENDERS AND FUEL TANKEBS00034FOOT PROTECTORS AND ENGINE SKID PLATE213T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..13 Nm (1.3 m • kg, 9.4 f

3 - 5CHKADJSEAT, FENDERS AND FUEL TANKEBS00036HEADLIGHTS AND FRONT FENDERT R..7 Nm (0.7 m • kg, 5.1 ft • Ib)2131456T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)

3 - 6CHKADJSEAT, FENDERS AND FUEL TANKEBS00039REAR FENDER632117T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)4T R..7 Nm (0.7 m

3 - 7CHKADJSEAT, FENDERS AND FUEL TANKEBS00042FUEL TANK213T R..7 Nm (0.7 m • kg, 5.1 ft • Ib)Order Job/Part Q’ty RemarksRemoving the fuel tankRemove t

3 - 8CHKADJADJUSTING THE VALVE CLEARANCEEAS00048ENGINEADJUSTING THE VALVE CLEARANCEThe following procedure applies to all of thevalves.NOTE:_ • Valve

3 - 9CHKADJADJUSTING THE VALVE CLEARANCE▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Turn the crankshaft counterclockwise. b. When the piston is at t

3 - 10CHKADJADJUSTING THE VALVE CLEARANCE6. Adjust: • valve clearance▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Remove the valve lifter 1 and the v

3 - 11CHKADJADJUSTING THE VALVE CLEARANCEEXAMPLE:Original valve pad number = 148 {thickness =1.48 mm (0.058 in)} Rounded value = 150d. Locate the roun

3 - 12CHKADJADJUSTING THE VALVE CLEARANCEINTAKE EXHAUSTMEASURED CLEARANCEINSTALLED PAD NUMBER120 125 130 135 140 145 150 155 160 165 170175 180 185 19

3 - 13CHKADJADJUSTING THE VALVE CLEARANCE/ADJUSTING THE ENGINE IDLING SPEED7. Install: • all removed partsNOTE:_ For installation, reverse the removal

3 - 14CHKADJADJUSTING THE ENGINE IDLING SPEED/ADJUSTING THE THROTTLE LEVER FREE PLAY6. Adjust: • engine idling speed▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼

3 - 15CHKADJADJUSTING THE THROTTLE LEVER FREE PLAY1. Measure: • throttle lever free play a Out of specification → Adjust.Throttle lever free play 2 ~

3 - 16CHKADJADJUSTING THE SPEED LIMITEREBS00053ADJUSTING THE SPEED LIMITERThe speed limiter keeps the carburetor throttlefrom becoming fully-opened ev

3 - 17CHKADJCHECKING THE SPARK PLUGEBS00057CHECKING THE SPARK PLUG1. Remove:• seat• fuel tank cover• side covers (left and right)• fuel tankNOTE:Slide

3 - 18CHKADJCHECKING THE SPARK PLUG/CHECKING THE IGNITION TIMING9. Install:• ignition coil• fuel tank• side covers (left and right)• fuel tank cover•

EBS00008TABLE OF CONTENTSGENERAL INFORMATIONGEN INFO1SPECIFICATIONSSPEC2PERIODIC CHECKS AND ADJUSTMENTSCHK ADJ3ENGINEENG4COOLING SYSTEMCOOL5CARBURETOR

3 - 19CHKADJCHECKING THE IGNITION TIMING/CHECKING THE ENGINE OIL LEVEL4. Check: • ignition timing▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Warm up

3 - 20CHKADJCHECKING THE ENGINE OIL LEVEL3. Check: • engine oil level Oil level should be between the minimumlevel mark a and the maximum level markb.

3 - 21CHKADJCHANGING THE ENGINE OILEBS00067CHANGING THE ENGINE OIL1. Remove:• engine skid plate Refer to “SEAT, FENDERS AND FUELTANK”.2. Start the eng

3 - 22CHKADJCHANGING THE ENGINE OIL9. If the oil filter element is also to be replaced,perform the following procedure.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼

3 - 23CHKADJCHANGING THE ENGINE OILSPCBXFF 13.Install: • dipstick• engine oil filler cap14.Start the engine, warm it up for several min-utes, and then

3 - 24CHKADJCHANGING THE ENGINE OIL/ADJUSTING THE CLUTCH CABLE17.Check: • engine oil pressure▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Slightly lo

3 - 25CHKADJADJUSTING THE CLUTCH CABLE2. Adjust: • clutch release lever free play▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼Handlebar sidea. Turn the

3 - 26CHKADJCLEANING THE AIR FILTER ELEMENTEBS00073CLEANING THE AIR FILTER ELEMENTNOTE:_ There is a check hose 1 at the bottom of theair filter case.

3 - 27CHKADJCLEANING THE AIR FILTER ELEMENT5. Clean: • air filter element ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Wash the element gently, but t

3 - 28CHKADJCHECKING THE COOLANT LEVEL/CHANGING THE COOLANTEBS00076CHECKING THE COOLANT LEVEL1. Place the machine on a level surface.2. Check: • coola