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Yamaha 2003 YZ450FR Owner's Service Manual

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OWNER'S SERVICE MANUAL
YZ450FR
LIT-11626-16-38
5TA-28199-10

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  • Page 1 OWNER’S SERVICE MANUAL YZ450FR LIT-11626-16-38 5TA-28199-10...
  • Page 3 EC010000 YZ450FR OWNER’S SERVICE MANUAL ©2002 by Yamaha Motor Corporation, U.S.A. 1st Edition, June 2002 All rights reserved. Any reprinting or unauthorized use without the written permission of Yamaha Motor Corporation U.S.A. is expressly prohibited. Printed in Japan P/N. LIT-11626-16-38...
  • Page 4 EC020000 INTRODUCTION Congratulations on your purchase of a Yamaha YZ series. This model is the culmina- tion of Yamaha’s vast experience in the pro- duction of pacesetting racing machines. It represents the highest grade of craftsmanship and reliability that have made Yamaha a leader.

  • Page 6: Important Notice

    IMPORTANT NOTICE 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 regula- tions before riding.
  • Page 7 6. GASOLINE CAN CAUSE INJURY. If you should swallow some gasoline, inhale excess gasoline vapors, or allow any gasoline to get into your eyes, contact a doctor immediately. If any gasoline spills onto your skin or clothing, immediately wash skin areas with soap and water, and change your clothes.
  • Page 8 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 perma- nent part of this machine and should remain with it even if the machine is subsequently sold.
  • Page 9 EC080000 HOW TO USE THIS MANUAL EC081000 PARTICULARLY IMPORTANT INFORMATION The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY INVOLVED! WARNING Failure to follow WARNING instructions could result in severe injury or death to the machine operator, a bystander, or a person inspecting or repairing the machine.
  • Page 10 EC083000 MANUAL FORMAT All of the procedures in this manual are organized in a sequential, step-by-step format. The informa- tion 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...
  • Page 11 ILLUSTRATED SYMBOLS (Refer to the illustration) SPEC Illustrated symbols 1 to 7 are designed as INFO thumb tabs to indicate the chapter’s number and content. 1 General information INSP 2 Specifications 3 Regular inspection and adjustments 4 Engine 5 Chassis 6 Electrical –...
  • Page 12 MEMO...
  • Page 13 EC090000 INDEX GENERAL INFORMATION INFO SPECIFICATIONS SPEC REGULAR INSPECTION AND INSP ADJUSTMENTS ENGINE CHASSIS CHAS – ELECTRICAL ELEC TUNING...

  • Page 14: Table Of Contents

    EC0A0000 CONTENTS CHAPTER 1 GENERAL INFORMATION DESCRIPTION .......... 1-1 MACHINE IDENTIFICATION ....1-2 IMPORTANT INFORMATION ....1-3 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 ....
  • Page 15 CHAPTER 4 ENGINE SEAT, FUEL TANK AND SIDE COVERS ......... 4-1 EXHAUST PIPE AND SILENCER .... 4-3 RADIATOR ..........4-5 CARBURETOR ......... 4-8 CAMSHAFTS .......... 4-21 CYLINDER HEAD ........4-29 VALVES AND VALVE SPRINGS ... 4-33 CYLINDER AND PISTON ....... 4-42 CLUTCH ..........
  • Page 16 CHAPTER 6 ELECTRICAL ELECTRICAL COMPONENTS AND WIRING DIAGRAM ......6-1 MAP-CONTROLLED CDI UNIT ....6-2 IGNITION SYSTEM ........6-3 TPS (THROTTLE POSITION SENSOR) SYSTEM ............ 6-7 CHAPTER 7 TUNING ENGINE ............. 7-1 CHASSIS ..........7-10...

  • Page 17: General Information

    DESCRIPTION INFO EC100000 GENERAL INFORMATION EC110000 DESCRIPTION NOTE: 1 Clutch lever The machine you have purchased may differ 2 Hot starter lever slightly from those shown in the following. 3 Front brake lever 4 Throttle grip Designs and specifications are subject to 5 Radiator cap change without notice.

  • Page 18: Machine Identification

    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 posi- tive 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.

  • Page 19: Important Information

    IMPORTANT INFORMATION INFO EC130000 IMPORTANT INFORMATION EC131010 PREPARATION FOR REMOVAL AND DISASSEMBLY 1. Remove all dirt, mud, dust, and foreign material before removal and disassem- bly. When washing the machine with high pressured water, cover the parts as fol- lows. Silencer exhaust port Side cover air intake port Water pump housing hole at the bottom...
  • Page 20 IMPORTANT INFORMATION INFO EC132000 ALL REPLACEMENT PARTS 1. We recommend to use Yamaha genuine parts for all replacements. Use oil and/or grease recommended by Yamaha for assembly and adjustment. EC133000 GASKETS, OIL SEALS AND O-RINGS 1. All gaskets, oil seals, and O-rings should be replaced when an engine is over- hauled.
  • Page 21 IMPORTANT INFORMATION INFO EC136000 CIRCLIPS 1. All circlips should be inspected carefully before reassembly. Always replace pis- ton pin clips after one use. Replace dis- torted circlips. When installing a circlip 1, make sure that the sharp-edged cor- ner 2 is positioned opposite to the thrust 3 it receives.

  • Page 22: Checking Of Connection

    CHECKING OF CONNECTION INFO EC1C0001 CHECKING OF CONNECTION Dealing with stains, rust, moisture, etc. on the connector. 1. Disconnect: Connector 2. Dry each terminal with an air blower. 3. Connect and disconnect the connector two or three times. 4. Pull the lead to check that it will not come off.

  • Page 23: Special Tools

    SPECIAL TOOLS INFO EC140001 SPECIAL TOOLS 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.
  • Page 24 Use this tool to remove and install the damper rod. YM-01442, 90890-01442 Fork seal driver YM-01442 90890-01442 This tool is used when install the fork oil seal. YU-3112-C, 90890-03112 Yamaha pocket tester YU-3112-C 90890-03112 Use this tool to inspect the coil resistance, output voltage and amperage. YU-8036-B Inductive tachometer...
  • Page 25 Dynamic spark tester YM-34487 90890-06754 90890-06754 Ignition checker This instrument is necessary for checking the ignition system components.  ACC-QUICK-GS-KT Quick gasket ACC-QUICK-GS-KT 90890-85505 90890-85505 YAMAHA Bond No. 1215 This sealant (Bond) is used for crankcase mating surface, etc. 1 - 9...

  • Page 26: Control Functions

    CONTROL FUNCTIONS INFO EC150000 CONTROL FUNCTIONS EC151000 “ENGINE STOP” BUTTON 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 han- dlebar;...
  • Page 27 CONTROL FUNCTIONS INFO EC156000 FRONT BRAKE LEVER The front brake lever 1 is located on the right handlebar. Pull it toward the handlebar to acti- vate the front brake. EC157000 REAR BRAKE PEDAL The rear brake pedal 1 is located on the right side of the machine.
  • Page 28 CONTROL FUNCTIONS INFO EC15R001 DETACHABLE SIDESTAND 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. EC15F000 VALVE JOINT This valve joint 1 prevents fuel from flowing out and is installed to the fuel tank breather hose.

  • Page 29: Fuel

    FUEL INFO FUEL Always use the recommended fuel as stated below. Also, be sure to use new gasoline the day of a race. Recommended fuel: Except for ZA: Premium unleaded gasoline only with a research octane number of 95 or higher. For ZA: Premium gasoline CAUTION:...

  • Page 30: Starting And Break-In

    STARTING AND BREAK-IN INFO STARTING AND BREAK-IN WARNING Never start or run the engine in a closed area. The exhaust fumes are poisonous; they can cause loss of consciousness and death in a very short time. Always operate the machine in a well-ventilated area. CAUTION: The carburetor on this motorcycle has a built-in...
  • Page 31 STARTING AND BREAK-IN INFO 6. 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 accelera- tor pump, if the engine is raced (the throttle opened and closed), the air/fuel mixture will be too rich and the engine may stall.
  • Page 32 STARTING AND BREAK-IN INFO STARTING A WARM ENGINE Do not operate the cold starter knob and throt- tle. 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.
  • Page 33 STARTING AND BREAK-IN INFO BREAK-IN PROCEDURES 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”...

  • Page 34: Torque-Check Points

    TORQUE-CHECK POINTS INFO TORQUE-CHECK POINTS Frame construction Frame to rear frame Combined seat and tank Fuel tank to frame Exhaust system Silencer to rear frame Engine mounting Frame to engine Engine bracket to engine Engine bracket to frame Steering Steering shaft to Steering shaft to frame handlebar Steering shaft to handle crown...

  • Page 35: Cleaning And Storage

    CLEANING AND STORAGE INFO EC1B0000 CLEANING AND STORAGE EC1B1000 CLEANING Frequent cleaning of your machine will enhance its appearance, maintain good over- all 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.
  • Page 36 CLEANING AND STORAGE INFO 8. Automotive wax may be applied to all painted or chromed surfaces. Avoid com- bination cleaner-waxes, as they may con- tain abrasives. 9. After completing the above, start the engine and allow it to idle for several min- utes.

  • Page 37: Specifications

    SPEC GENERAL SPECIFICATIONS EC200000 SPECIFICATIONS EC211000 GENERAL SPECIFICATIONS Model name: YZ450FR (USA) YZ450F (EUROPE) YZ450F(R) (CDN, AUS, NZ, ZA) Model code number: 5TA1 (USA) 5TA2 (EUROPE) 5TA4 (CDN, AUS, NZ, ZA) Dimensions: Overall length 2,171 mm (85.5 in) Overall width 827 mm (32.6 in) Overall height 1,303 mm (51.3 in)
  • Page 38 SPEC GENERAL SPECIFICATIONS Oil capacity: Engine oil Periodic oil change 1.0 L (0.88 Imp qt, 1.06 US qt) With oil filter replacement 1.1 L (0.97 Imp qt, 1.16 US qt) Total amount 1.2 L (1.06 Imp qt, 1.27 US qt) Coolant capacity (including all routes): 1.2 L (1.06 Imp qt, 1.27 US qt) Air filter:...
  • Page 39 SPEC GENERAL SPECIFICATIONS Brake: Front brake type Single disc brake Operation Right hand operation Rear brake type Single disc brake Operation Right foot operation Suspension: Front suspension Telescopic fork Rear suspension Swingarm (link type monocross suspension) Shock absorber: Front shock absorber Coil spring/oil damper Rear shock absorber Coil spring/gas, oil damper...

  • Page 40: Maintenance Specifications

    SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Item Standard Limit Cylinder head: Warp limit ---- 0.05 mm (0.002 in) Cylinder: Bore size 95.00 ~ 95.01 mm ---- (3.7402 ~ 3.7406 in) Out of round limit ---- 0.05 mm (0.002 in) Camshaft: Drive method Chain drive (Left) ----...
  • Page 41 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Cam chain: Cam chain type/No. of links 98XRH2010-118M/118 ---- Cam chain adjustment method Automatic ---- Valve, valve seat, valve guide: Valve clearance (cold) 0.10 ~ 0.15 mm ---- (0.0039 ~ 0.0059 in) 0.20 ~ 0.25 mm ---- (0.0079 ~ 0.0098 in) Valve dimensions:...
  • Page 42 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Valve spring: Free length 37.03 mm (1.46 in) 35.17 mm (1.38 in) 37.68 mm (1.48 in) 35.79 mm (1.41 in) Set length (valve closed) 27.87 mm (1.10 in) ---- 27.38 mm (1.08 in) ---- Compressed force (installed) 111.3 ~ 127.9 N at 27.87 mm...
  • Page 43 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Piston rings: Top ring: Type Barrel ---- Dimensions (B × T) 1.2 × 3.5 mm (0.05 × 0.14 in) ---- End gap (installed) 0.20 ~ 0.30 mm 0.55 mm (0.008 ~ 0.012 in) (0.022 in) Side clearance (installed) 0.030 ~ 0.065 mm 0.12 mm...
  • Page 44 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Clutch: Friction plate thickness 2.92 ~ 3.08 mm 2.8 mm (0.115 ~ 0.121 in) (0.110 in) Quantity ---- Clutch plate thickness 1.1 ~ 1.3 mm (0.043 ~ 0.051 in) ---- Quantity ---- Warp limit ---- 0.1 mm (0.004 in)
  • Page 45 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Lubrication system: Oil filter type Wire mesh type ---- Oil pump type Trochoid type ---- Tip clearance “A” 0.12 mm or less 0.20 mm (0.0047 in or less) (0.008 in) Tip clearance “B” 0.09 ~ 0.17 mm 0.24 mm (0.0035 ~ 0.0067 in) (0.009 in)
  • Page 46 SPEC MAINTENANCE SPECIFICATIONS Item Standard Lubrication chart: Pressure feed Oil tank Splashed scavenge Camshaft Cylinder head Valve lifter Piston Transmission gears Piston pin Main axle Crank pin Oil filter Drive axle Check ball Oil pump rotor 1 Oil pump rotor 2 Oil strainer Oil pan 2 - 10...
  • Page 47 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb M10S × 1.0 Spark plug M6 × 1.0 Camshaft cap M12 × 1.0 Cylinder head blind plug screw M6 × 1.0 Cylinder head (stud bolt) M8 × 1.25 M10 ×...
  • Page 48 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb M6 × 1.0 Crankcase cover (right) M6 × 1.0 Crankcase cover (left) M6 × 1.0 Crankcase M6 × 1.0 Clutch cable holder M10 × 1.25 Oil drain bolt (crankcase rear) M6 ×...
  • Page 49 SPEC MAINTENANCE SPECIFICATIONS EC212201 CHASSIS Item Standard Limit Steering system: Steering bearing type Taper roller bearing ---- Front suspension: Front fork travel 300 mm (11.8 in) ---- Fork spring free length 460 mm (18.1 in) 455 mm (17.9 in) Spring rate, STD K = 4.51 N/mm ---- (0.46 kg/mm, 25.8 lb/in)
  • Page 50 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Wheel: Front wheel type Spoke wheel ---- Rear wheel type Spoke wheel ---- 21 × 1.60/Aluminum Front rim size/material ---- 19 × 2.15/Aluminum Rear rim size/material ---- Rim runout limit: Radial ---- 2.0 mm (0.08 in) Lateral ---- 2.0 mm (0.08 in)
  • Page 51 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb M8 × 1.25 Handle crown and outer tube M8 × 1.25 Under bracket and outer tube M24 × 1.0 Handle crown and steering shaft 14.5 M8 × 1.25 Handlebar holder (upper) M28 ×...
  • Page 52 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb M20 × 1.5 Rear wheel axle and nut 12.5 M8 × 1.25 Driven sprocket and wheel hub Nipple (spoke) – M6 × 1.0 Disc cover and rear brake caliper M6 ×...
  • Page 53 Limit Ignition system: Advancer type Electrical ---- C.D.I.: Magneto-model (stator)/manufacturer 5SF-00/YAMAHA ---- 720 ~ 1,080 Ω at 20 ˚C (68 ˚F) Source coil 1 resistance (color) ---- (Green – Brown) 44 ~ 66 Ω at 20 ˚C (68 ˚F) Source coil 2 resistance (color) ---- (Black –...

  • Page 54: General Torque Specifications

    GENERAL TORQUE SPECIFICATIONS/ SPEC DEFINITION OF UNITS EC220001 GENERAL TORQUE SPECIFICATIONS This chart specifies torque for standard fasten- ers with standard I.S.O. pitch threads. Torque specifications for special components or assemblies are included in the applicable sec- tions of this book. To avoid warpage, tighten multi-fastener assemblies in a crisscross fash- ion, in progressive stages, until full torque is reached.

  • Page 55: Lubrication Diagrams

    SPEC LUBRICATION DIAGRAMS LUBRICATION DIAGRAMS 1 Oil delivery pipe 2 Intake camshaft 3 Exhaust camshaft 4 Oil cleaner element 5 Oil pump 6 Main axle 7 Drive axle D - D A - A 2 - 19...
  • Page 56 SPEC LUBRICATION DIAGRAMS 1 Camshaft 2 Connecting rod 3 Oil cleaner element 4 Crankshaft 5 Main axle 6 Drive axle 7 Oil delivery pipe 2 - 20...

  • Page 57: Cable Routing Diagram

    SPEC CABLE ROUTING DIAGRAM EC240000 CABLE ROUTING DIAGRAM Î Fit the brake hose into the 1 Fuel tank breather hose G Carburetor breather hose 2 Hot starter cable H Overflow hose guides on the protector. ‰ Fasten the “ENGINE STOP” 3 Radiator hose 4 Å...
  • Page 58 SPEC CABLE ROUTING DIAGRAM Ó Pass the sub wire harness ˆ Pass the neutral switch lead, Decompression cable (sup- between the engine brackets. CDI magneto lead and radiator plied for Europe and optional È Make sure that the TPS lead breather hose between the for other destinations) coupler does not go outside the...
  • Page 59 SPEC CABLE ROUTING DIAGRAM Å Fasten the grommet of the clutch Ì Insert the CDI unit band over the 1 Cable holder 2 CDI unit cable with the cable holder. CDI unit bracket as far as possi- ı Pass the hot starter cable, clutch 3 Hot starter cable ble.
  • Page 60 SPEC CABLE ROUTING DIAGRAM Å Install the brake hose so that its 1 Master cylinder 2 Brake hose holder pipe portion directs as shown and 3 Brake hose lightly touches the projection on the caliper. ı Pass the brake hose into the brake hose holders.
  • Page 61 SPEC CABLE ROUTING DIAGRAM Å Fasten the “ENGINE STOP” but- 1 Throttle cable 2 Fuel tank breather hose ton lead to the handlebar with the 3 Clamp plastic band. ı Pass the brake hose in front of the 4 Clutch cable 5 Hot starter cable number plate.

  • Page 62: Regular Inspection And Adjustments

    If you are a doubt as to what intervals to follow in maintaining and lubricating your machine, consult your Yamaha dealer. Every...
  • Page 63 INSP MAINTENANCE INTERVALS Every Every After Every As re- third fifth Item Remarks break-in race quired 500 km) 1,000 km) SHIFT FORK, SHIFT CAM, GUIDE BAR ● Inspect Inspect wear ROTOR NUT ● ● Retighten MUFFLER ● ● Inspect and retighten ●...
  • Page 64 ● Retighten sprocket bolt ● Inspect bearings ● Replace bearings ● Lubricate Lithium base grease THROTTLE, CONTROL CABLE Yamaha cable lube or ● ● Check routing and connection SAE 10W-30 motor oil ● ● Lubricate HOT STARTER, CLUTCH LEVER ●...

  • Page 65: Pre-Operation Inspection And Maintenance

    INSP PRE-OPERATION INSPECTION AND MAINTENANCE EC320000 PRE-OPERATION INSPECTION AND MAINTENANCE Before riding for break-in operation, practice or a race, make sure the machine is in good operating condition. Before using this machine, check the following points. GENERAL INSPECTION AND MAINTENANCE Item Routine Page...

  • Page 66: Engine

    INSP ENGINE/COOLANT LEVEL INSPECTION EC350000 ENGINE EC351011 COOLANT LEVEL INSPECTION WARNING Do not remove the radiator cap 1, drain bolt and hoses when the engine and radia- tor are hot. Scalding hot fluid and steam may be blown out under pressure, which could cause serious injury.
  • Page 67 INSP COOLANT REPLACEMENT EC353011 COOLANT REPLACEMENT WARNING 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. 1. Place a container under the engine. 2.
  • Page 68 INSP RADIATOR CAP INSPECTION CAUTION: Do not mix more than one type of ethyl- ene glycol antifreeze containing corro- sion inhibitors for aluminum engine. Do not use water containing impurities or oil. Handling notes of coolant: The coolant is harmful so it should be han- dled with special care.
  • Page 69 RADIATOR CAP OPENING PRESSURE INSPECTION/ INSP COOLING SYSTEM INSPECTION EC356001 RADIATOR CAP OPENING PRESSURE INSPECTION 1. Attach: Radiator cap tester 1 and adapter 2 Radiator cap tester: YU-24460-01/90890-01325 Adapter: YU-33984/90890-01352 NOTE: Apply water on the radiator cap seal. 3 Radiator cap 2.
  • Page 70 INSP CLUTCH ADJUSTMENT NOTE: 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 →...
  • Page 71 THROTTLE CABLE ADJUSTMENT/ INSP THROTTLE LUBRICATION EC35A001 THROTTLE CABLE ADJUSTMENT 1. Check: Throttle grip free play a Out of specification → Adjust. Throttle grip free play a: 3 ~ 5 mm (0.12 ~ 0.20 in) 2. Adjust: Throttle grip free play Throttle grip free play adjustment steps: Slide the adjuster cover.
  • Page 72 HOT STARTER LEVER ADJUSTMENT/ INSP AIR FILTER CLEANING HOT STARTER LEVER ADJUSTMENT 1. Check: Hot starter lever free play a Out of specification → Adjust. Hot starter lever free play a: 3 ~ 6 mm (0.12 ~ 0.24 in) 2. Adjust: Hot starter lever free play Hot starter lever free play adjustment steps:...
  • Page 73 INSP AIR FILTER CLEANING 2. Clean: Air filter element Clean them with solvent. NOTE: After cleaning, remove the remaining solvent by squeezing the element. CAUTION: Do not twist the element when squeezing the element. Leaving too much of solvent in the ele- ment may result in poor starting.
  • Page 74 INSP ENGINE OIL LEVEL INSPECTION 7. Install: Air filter element 1 Washer Fitting bolt 2 Nm (0.2 m · kg, 1.4 ft · lb) NOTE: Align the projection a on filter guide with the hole b in air filter case. ENGINE OIL LEVEL INSPECTION 1.
  • Page 75 INSP ENGINE OIL LEVEL INSPECTION 4. Inspect: Oil level Oil level should be between maximum a and minimum b marks. Oil level low → Add oil to proper level. NOTE: When inspecting the oil level, do not screw the oil level gauge into the oil tank. Insert the gauge lightly.
  • Page 76 INSP ENGINE OIL REPLACEMENT 5. Start the engine and let it warm up for several minutes. CAUTION: When the oil tank is empty, never start the engine. 6. Idle the engine more than 10 seconds while keeping the motorcycle upright. Then stop the engine and add the oil to the maximum level.
  • Page 77 INSP ENGINE OIL REPLACEMENT 6. If the oil filter is to be replaced during this oil change, remove the following parts and reinstall them. Replacement steps: Remove the exhaust pipe. Remove the oil filter cover 1 and oil filter element 2. Check the O-rings 3 , if cracked or dam- aged, replace them with a new one.
  • Page 78 INSP PILOT SCREW ADJUSTMENT 12. Check: Oil pressure Checking steps: Slightly loosen the oil gallery bolt 1. Start the engine and keep it idling until oil starts to seep from the oil gallery bolt. If no oil comes out after one minute, turn the engine off so it will not seize.
  • Page 79 IDLE SPEED ADJUSTMENT/ INSP VALVE CLEARANCE ADJUSTMENT EC35M021 IDLE SPEED ADJUSTMENT 1. Start the engine and thoroughly warm it 2. Adjust: Idle speed Adjustment steps: Adjust the pilot screw. Refer to “PILOT SCREW ADJUSTMENT” section. Turn the throttle stop screw 1 until the engine runs at the lowest possible speed.
  • Page 80 INSP VALVE CLEARANCE ADJUSTMENT 4. Check: Valve clearance Out of specification → Adjust. 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.
  • Page 81 INSP VALVE CLEARANCE ADJUSTMENT 5. Adjust: Valve clearance Adjustment steps: Loosen the timing chain tensioner cap bolt. Remove the timing chain tensioner and camshaft caps. NOTE: Remove the camshaft cap bolts in a criss- cross pattern from the outside working inwards.
  • Page 82 INSP VALVE CLEARANCE ADJUSTMENT Round off the last digit of the installed pad number to the nearest increment. Last digit of pad Rounded value number 0, 1 or 2 4, 5 or 6 8 or 9 EXAMPLE: Installed pad number = 148 Rounded off value = 150 NOTE: Pads can only be selected in 0.05 mm incre-...
  • Page 83 INSP VALVE CLEARANCE ADJUSTMENT Install the timing chain tensioner. Refer to “CAMSHAFTS” section in the CHAPTER 4. NOTE: Turn the crankshaft counterclockwise sev- eral 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.
  • Page 84 INSP VALVE CLEARANCE ADJUSTMENT INTAKE MEASURED INSTALLED PAD NUMBER CLEARANCE 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235 240 0.00 ~ 0.04 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 0.05 ~ 0.09 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235 0.10 ~ 0.15...

  • Page 85: Chassis

    INSP CHASSIS/BRAKE SYSTEM AIR BLEEDING EC360000 CHASSIS EC361012 BRAKE SYSTEM AIR BLEEDING WARNING 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. Å...
  • Page 86 INSP FRONT BRAKE ADJUSTMENT NOTE: 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 disap- peared. j. Add brake fluid to the level line on the reservoir.

  • Page 87: Rear Brake Adjustment

    REAR BRAKE ADJUSTMENT/ INSP FRONT BRAKE PAD INSPECTION AND REPLACEMENT EC364002 REAR BRAKE ADJUSTMENT 1. Check: Brake pedal height a Out of specification → Adjust. Brake pedal height a: 5 mm (0.20 in) 2. Adjust: Brake pedal height Pedal height adjustment steps: Loosen the locknut 1.
  • Page 88 INSP FRONT BRAKE PAD INSPECTION AND REPLACEMENT Loosen the pad pin 2. Remove the brake hose holder 3 and cal- iper 4 from the front fork. Remove the pad pin and brake pads 5. Connect the transparent hose 6 to the bleed screw 7 and place the suitable con- tainer under its end.
  • Page 89 INSP REAR BRAKE PAD INSPECTION AND REPLACEMENT Install the pad pin plug B. Pad pin plug: 3 Nm (0.3 m • kg, 2.2 ft • lb) 3. Inspect: Brake fluid level Refer “BRAKE FLUID LEVEL INSPECTION” section. 4. Check: Brake lever operation A softy or spongy feeling →...
  • Page 90 INSP REAR BRAKE PAD INSPECTION AND REPLACEMENT Remove the pad pin 6 and brake pads 7. Connect the transparent hose 8 to the bleed screw 9 and place the suitable con- tainer under its end. Loosen the bleed screw and push the cali- per piston in.
  • Page 91 REAR BRAKE PAD INSULATOR INSPECTION/ INSP BRAKE FLUID LEVEL INSPECTION 3. Inspect: Brake fluid level Refer “BRAKE FLUID LEVEL INSPECTION” section. 4. Check: Brake pedal operation A softy or spongy feeling → Bleed brake system. Refer “BRAKE SYSTEM BLEEDING” section. EC36b000 REAR BRAKE PAD INSULATOR INSPECTION...
  • Page 92 INSP SPROCKETS INSPECTION/DRIVE CHAIN INSPECTION EC368000 SPROCKETS INSPECTION 1. Inspect: Sprocket teeth a Excessive wear → Replace. NOTE: Replace the drive, driven sprockets and drive chain as a set. EC369002 DRIVE CHAIN INSPECTION 1. Remove: Master link clip Joint 1 Drive chain 2 2.
  • Page 93 INSP DRIVE CHAIN SLACK ADJUSTMENT 5. Install: Drive chain 1 Joint 2 Master link clip 3 CAUTION: Be sure to install the master link clip to the direction as shown. a Turning direction 6. Lubricate: Drive chain Drive chain lubricant: SAE 10W-30 motor oil or suit- able chain lubricants DRIVE CHAIN SLACK ADJUSTMENT...
  • Page 94 INSP FRONT FORK INSPECTION 3. Adjust: Drive chain slack Drive chain slack adjustment steps: Loosen the axle nut 1 and locknuts 2. Adjust chain slack by turning the adjusters To tighten → Turn adjuster 3 counter- clockwise. To loosen → Turn adjuster 3 clockwise and push wheel forward.
  • Page 95 FRONT FORK OIL SEAL AND DUST SEAL CLEANING/ INSP FRONT FORK INTERNAL PRESSURE RELIEVING/ FRONT FORK REBOUND DAMPING FORCE ADJUSTMENT EC36D001 FRONT FORK OIL SEAL AND DUST SEAL CLEANING 1. Remove: Protector Dust seal 1 NOTE: Use a thin screw driver, and be careful not to damage the inner fork tube and dust seal.
  • Page 96 FRONT FORK COMPRESSION DAMPING FORCE INSP ADJUSTMENT Extent of adjustment: Maximum Minimum 20 clicks out (from Fully turned in maximum posi- position tion) STANDARD POSITION: This is the position which is back by the spe- cific number of clicks from the fully turned-in position.

  • Page 97: Rear Shock Absorber Inspection

    INSP REAR SHOCK ABSORBER INSPECTION Extent of adjustment: Maximum Minimum 20 clicks out Fully turned in (from maximum position position) STANDARD POSITION: This is the position which is back by the spe- cific number of clicks from the fully turned-in position.
  • Page 98 REAR SHOCK ABSORBER SPRING PRELOAD INSP ADJUSTMENT REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT 1. Elevate the rear wheel by placing the suitable stand under the engine. 2. Remove: Rear frame 3. Loosen: Locknut 1 4. Adjust: Spring preload By turning the adjuster 2. Stiffer →...
  • Page 99 REAR SHOCK ABSORBER REBOUND INSP DAMPING FORCE ADJUSTMENT EC36N014 REAR SHOCK ABSORBER REBOUND DAMPING FORCE ADJUSTMENT 1. Adjust: Rebound damping force By turning the adjuster 1. Stiffer a → Increase the rebound damp- ing force. (Turn the adjuster 1 in.) Softer b →...
  • Page 100 REAR SHOCK ABSORBER LOW COMPRESSION INSP DAMPING FORCE ADJUSTMENT EC36c000 REAR SHOCK ABSORBER LOW COMPRESSION DAMPING FORCE ADJUSTMENT 1. Adjust: Low compression damping force By turning the adjuster 1. Stiffer a → Increase the low compres- sion damping force. (Turn the adjuster 1 in.) Softer b →...
  • Page 101 REAR SHOCK ABSORBER HIGH COMPRESSION INSP DAMPING FORCE ADJUSTMENT EC36d000 REAR SHOCK ABSORBER HIGH COMPRESSION DAMPING FORCE ADJUSTMENT 1. Adjust: High compression damping force By turning the adjuster 1. Stiffer a → Increase the high compres- sion damping force. (Turn the adjuster 1 in.) Softer b →...
  • Page 102 TIRE PRESSURE CHECK/SPOKES INSPECTION AND INSP TIGHTENING/WHEEL INSPECTION EC36Q000 TIRE PRESSURE CHECK 1. Measure: Tire pressure Out of specification → Adjust. Standard tire pressure: 100 kPa (1.0 kgf/cm , 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.
  • Page 103 INSP STEERING HEAD INSPECTION AND ADJUSTMENT 2. Inspect: Bearing free play Exist play → Replace. STEERING HEAD INSPECTION AND ADJUSTMENT 1. Elevate the front wheel by placing a suit- able stand under the engine. 2. Check: Steering shaft Grasp the bottom of the forks and gen- tly rock the fork assembly back and forth.
  • Page 104 INSP STEERING HEAD INSPECTION AND ADJUSTMENT Tighten the ring nut 3 using ring nut wrench 4. NOTE: 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. Ring nut wrench: YU-33975/90890-01403 Ring nut (initial tightening):...
  • Page 105 INSP LUBRICATION Å Use Yamaha cable lube or equivalent on these LUBRICATION areas. To ensure smooth operation of all compo- ı Use SAE 10W-30 motor oil or suitable chain nents, lubricate your machine during setup, lubricants. after break-in, and after every race.

  • Page 106: Electrical

    INSP ELECTRICAL/SPARK PLUG INSPECTION EC370000 ELECTRICAL EC371001 SPARK PLUG INSPECTION 1. Remove: Spark plug 2. Inspect: Electrode 1 Wear/damage → Replace. Insulator color 2 Normal condition is a medium to light tan color. Distinctly different color → Check the engine condition. NOTE: When the engine runs for many hours at low speeds, the spark plug insulator will become...
  • Page 107 INSP IGNITION TIMING CHECK IGNITION TIMING CHECK 1. Remove: Timing plug 1 2. Attach: Timing light Inductive tachometer To the spark plug lead. Timing light: YM-33277-A/90890-03141 Inductive tachometer: YU-8036-B Engine tachometer: 90890-03113 3. Check: Ignition timing Checking steps: Start the engine and let it warm up. Let the engine run at the specified speed.

  • Page 108: Seat, Fuel Tank And Side Covers

    SEAT, FUEL TANK AND SIDE COVERS EC400000 ENGINE EC4R0000 SEAT, FUEL TANK AND SIDE COVERS Extent of removal: 1 Seat removal 2 Fuel tank removal 3 Side covers removal 4 Number plate removal Extent of removal Order Part name Q’ty Remarks SEAT, FUEL TANK AND SIDE COVERS REMOVAL...
  • Page 109 SEAT, FUEL TANK AND SIDE COVERS REMOVAL POINTS Side cover 1. Remove: Bolt (side cover) Side cover (left) 1 Side cover (right) 2 NOTE: Draw the side cover downward to remove it because its claws a are inserted in the air fil- ter case.

  • Page 110: Exhaust Pipe And Silencer

    EXHAUST PIPE AND SILENCER EC4S0000 EXHAUST PIPE AND SILENCER Å Except for USA Extent of removal: 1 Silencer removal 2 Exhaust pipe removal Extent of removal Order Part name Q’ty Remarks EXHAUST PIPE AND SILENCER REMOVAL Preparation for removal Side cover (right) Refer to “SEAT, FUEL TANK AND SIDE COVERS”...
  • Page 111 EXHAUST PIPE AND SILENCER INSPECTION Exhaust pipe and silencer 1. Inspect: Gasket 1 Damage → Replace. ASSEMBLY AND INSTALLATION Exhaust pipe and silencer 1. Install: Gasket Exhaust pipe 1 Nut (exhaust pipe) 2 13 Nm (1.3 m · kg, 9.4 ft · lb) Bolt (exhaust pipe) 3 24 Nm (2.4 m ·...

  • Page 112: Radiator

    RADIATOR EC450001 RADIATOR Extent of removal: 1 Radiator removal Extent of removal Order Part name Q’ty Remarks RADIATOR REMOVAL Preparation for removal Drain the coolant. Refer to “COOLANT REPLACEMENT” section in the CHAPTER 3. Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE COVERS”...
  • Page 113 RADIATOR EC456000 HANDLING NOTE WARNING 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 radi- ator cap by the following procedure: Place a thick rag, like a towel, over the radi- ator cap, slowly rotate the cap counter-...
  • Page 114 RADIATOR 3. Install: Radiator breather hose 1 Radiator (right) 2 10 Nm (1.0 m · kg, 7.2 ft · lb) Refer to “CABLE ROUTING DIA- GRAM” section in the CHAPTER 2. 4. Install: Panel 1 Bolt (radiator panel upper) 2 10 Nm (1.0 m ·...

  • Page 115: Carburetor

    CARBURETOR CARBURETOR 4 Nm (0.4 m kg, 2.9 ft • • 2 Nm (0.2 m kg, 1.4 ft • • 3 Nm (0.3 m kg, 2.2 ft • • 3 Nm (0.3 m kg, 2.2 ft • • Extent of removal: 1 Carburetor removal Extent of removal Order...
  • Page 116 CARBURETOR CARBURETOR DISASSEMBLY Extent of removal: 1 Carburetor disassembly Extent of removal Order Part name Q’ty Remarks CARBURETOR DISASSEMBLY Breather hose Valve lever housing cover Screw (throttle shaft) Throttle valve Needle holder Jet needle Cover Spring Diaphragm (accelerator pump) Float chamber Pilot screw Refer to “REMOVAL POINTS”.
  • Page 117 CARBURETOR Extent of removal Order Part name Q’ty Remarks Main jet Needle jet Spacer Pilot jet Starter jet Push rod Pull the push rod. Throttle shaft assembly Push rod link lever assembly Pilot air jet Cold starter plunger 4 - 10...
  • Page 118 CARBURETOR EC466020 HANDLING NOTE CAUTION: 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: Pilot screw 1 NOTE: To optimize the fuel flow at a small throttle...
  • Page 119 CARBURETOR 2. Inspect: Main jet 1 Pilot jet 2 Needle jet 3 Starter jet 4 Pilot air jet 5 Damage → Replace. Contamination → Clean. NOTE: Use a petroleum based solvent for cleaning. Blow out all passages and jets with com- pressed air.
  • Page 120 CARBURETOR EC464511 Float height 1. Measure: Float height a Out of specification → Adjust. 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.
  • Page 121 CARBURETOR Starter plunger 1. Inspect: Cold starter plunger 1 Hot starter plunger 2 Wear/damage → Replace. Accelerator pump 1. Inspect: Diaphragm (accelerator pump) 1 Spring 2 Cover 3 O-ring 4 Push rod 5 Tears (diaphragm)/damage → Replace. Dirt → Clean. 2.
  • Page 122 CARBURETOR 3. Install: Spring 1 1 Lever 1 2 To lever 2 3. NOTE: Make sure the spring 1 fits on the stopper a of the lever 2. 4. Install: Spring 2 1 To lever 2 2. 5. Install: Push rod link lever assembly 1 NOTE: Make sure the stopper a of the spring 2 fits into the recess b in the carburetor.
  • Page 123 CARBURETOR 8. Install: 1 2 3 Throttle shaft assembly 1 Plain washer (metal) 2 Plain washer (resin) 3 Valve lever 4 NOTE: Apply the fluorochemical grease on the bear- ings. Fit the projection a on the throttle shaft assembly into the slot b in the TPS (throttle position sensor).
  • Page 124 CARBURETOR 11. 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. 12. Install: Pilot screw 1 Spring 2 Washer 3 O-ring 4 Note the following installation points: Turn in the pilot screw until it is lightly...
  • Page 125 CARBURETOR 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 a of the throttle valve.
  • Page 126 CARBURETOR Accelerator pump timing adjustment Adjustment steps: NOTE: In order for the throttle valve height a 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.
  • Page 127 CARBURETOR 4. Tighten: Screw (air cleaner joint) 1 3 Nm (0.3 m · kg, 2.2 ft · lb) Screw (carburetor joint) 2 3 Nm (0.3 m · kg, 2.2 ft · lb) 5. Install: Throttle cable 1 6. Adjust: Throttle grip free play Refer to “THROTTLE CABLE ADJUST- MENT”...

  • Page 128: Camshafts

    CAMSHAFTS CAMSHAFTS CYLINDER HEAD COVER Extent of removal: 1 Cylinder head cover removal Extent of removal Order Part name Q’ty Remarks CYLINDER HEAD COVER REMOVAL Preparation for removal Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE COVERS” section. Carburetor Refer to “CARBURETOR”...
  • Page 129 CAMSHAFTS CAMSHAFTS Extent of removal: 1 Camshaft removal Extent of removal Order Part name Q’ty Remarks CAMSHAFTS REMOVAL Timing plug Straight plug Tensioner cap bolt Timing chain tensioner Gasket Refer to “REMOVAL POINTS”. Bolt (camshaft cap) Camshaft cap Clip Exhaust camshaft Intake camshaft 4 - 22...
  • Page 130 CAMSHAFTS REMOVAL POINTS Camshaft 1. Remove: Timing plug 1 Straight plug 2 2. Align: “I” mark With stationary pointer. Checking steps: Turn the crankshaft counterclockwise with a wrench. Align the “I” mark a on the rotor with the stationary pointer b on the crankcase cover.
  • Page 131 CAMSHAFTS 6. Remove: Clips Exhaust camshaft 1 Intake camshaft 2 NOTE: Attach a wire 3 to the timing chain to prevent it from falling into the crankcase. INSPECTION Camshaft 1. Inspect: Cam lobes Pitting/scratches/blue discoloration → Replace. 2. Measure: Cam lobes length a and b Out of specification →...
  • Page 132 CAMSHAFTS 4. Measure: Camshaft-to-cap clearance Out of specification → Measure cam- shaft journal diameter. Camshaft-to-cap clearance: 0.020 ~ 0.054 mm (0.0008 ~ 0.0021 in) <Limit>: 0.08 mm (0.003 in) Measurement steps: Install the camshaft onto the cylinder head. ® Position a strip of Plastigauge 1 onto the camshaft.
  • Page 133 CAMSHAFTS Decompression system 1. Check: 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: While pressing the tensioner rod lightly with fingers, use a thin screwdriver 1 and wind the tensioner rod up fully clockwise.
  • Page 134 CAMSHAFTS 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 c and the intake cam sprocket punch mark d align with the sur- face of the cylinder head.
  • Page 135 CAMSHAFTS With the rod fully wound and the chain tensioner UP mark a facing upward, install the gasket 1 and the chain ten- sioner 2, and tighten the bolt 3 to the specified torque. Bolt (timing chain tensioner): 10 Nm (1.0 m • kg, 7.2 ft • lb) Release the screwdriver, check the ten- sioner rod to come out and tighten the gasket 4 and the cap bolt 5 to the speci-...

  • Page 136: Cylinder Head

    CYLINDER HEAD CYLINDER HEAD CYLINDER HEAD Extent of removal: 1 Cylinder head removal Extent of removal Order Part name Q’ty Remarks CYLINDER HEAD REMOVAL Preparation for removal Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE COVERS” section. Exhaust pipe and silencer Refer to “EXHAUST PIPE AND SILENCER”...
  • Page 137 CYLINDER HEAD INSPECTION Cylinder head 1. Eliminate: Carbon deposits (from the combustion chambers) Use a rounded scraper. NOTE: Do not use a sharp instrument to avoid dam- aging or scratching: Spark plug threads Valve seats 2. Inspect: Cylinder head Scratches/damage → Replace. 3.
  • Page 138 CYLINDER HEAD ASSEMBLY AND INSTALLATION 1. Install: Timing chain guide (front) 1 Dowel pin 2 Cylinder head gasket 3 Cylinder head 4 NOTE: While pulling up the timing chain, install the timing chain guide (front) and cylinder head. 2. Install: Plain washer 1 Bolt [L=160 mm (6.30 in)] 2 Bolt [L=150 mm (5.91 in)] 3...
  • Page 139 CYLINDER HEAD Remove the bolts. Again apply the molybdenum disulfide grease on the threads and contact sur- faces of the bolts and on both contact sur- faces 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.

  • Page 140: Valves And Valve Springs

    VALVES AND VALVE SPRINGS VALVES AND VALVE SPRINGS VALVES AND VALVE SPRINGS Extent of removal: 1 Valve removal Extent of removal Order Part name Q’ty Remarks VALVES AND VALVE SPRINGS REMOVAL Preparation for removal Cylinder head Refer to “CYLINDER HEAD” section. Valve lifter Use special tool.
  • Page 141 VALVES AND VALVE SPRINGS REMOVAL POINTS 1. Remove: Valve lifters 1 Pads 2 NOTE: Identify each lifter 1 and pad 2 position very carefully so that they can be reinstalled in their original place. 2. Check: Valve sealing Leakage at the valve seat → Inspect the valve face, valve seat and valve seat width.
  • Page 142 VALVES AND VALVE SPRINGS INSPECTION Valve 1. Measure: Stem-to-guide clearance Stem-to-guide clearance = valve guide inside diameter a – valve stem diameter b Out of specification → Replace the valve guide. Clearance (stem to guide): Intake: 0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in) <Limit>: 0.08 mm (0.003 in) Exhaust:...
  • Page 143 VALVES AND VALVE SPRINGS Valve guide remover: 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...
  • Page 144 VALVES AND VALVE SPRINGS 5. Measure: Runout (valve stem) Out of specification → Replace. Runout limit: 0.01 mm (0.0004 in) NOTE: When installing a new valve always replace the guide. If the valve is removed or replaced always replace the oil seal. 6.
  • Page 145 VALVES AND VALVE SPRINGS 9. Lap: Valve face Valve seat NOTE: After refacing the valve seat or replacing the valve and valve guide, the valve seat and valve face should be lapped. Lapping steps: Apply a coarse lapping compound to the valve face.
  • Page 146 VALVES AND VALVE SPRINGS Valve spring 1. Measure: Valve spring free length a Out of specification → Replace. Free length (valve spring): Intake: 37.03 mm (1.46 in) <Limit>: 35.17 mm (1.38 in) Exhaust: 37.68 mm (1.48 in) <Limit>: 35.79 mm (1.41 in) 2.
  • Page 147 VALVES AND VALVE SPRINGS Combination of cylinder head and valve lifter 1. Combination: For this combination, match the paint color on the cylinder head with that on the valve lifter according to the chart below. Combination Cylinder head mark Valve lifter mark a (color) b (color) Blue...
  • Page 148 VALVES AND VALVE SPRINGS 3. Install: Valve cotters NOTE: While compressing the valve spring with a valve spring compressor 1 install the valve cotters. Valve spring compressor: YM-4019/90890-04019 4. To secure the valve cotters onto the valve stem, lightly tap the valve tip with a piece of wood.

  • Page 149: Cylinder And Piston

    CYLINDER AND PISTON CYLINDER AND PISTON CYLINDER AND PISTON Extent of removal: 1 Cylinder removal 2 Piston removal Extent of removal Order Part name Q’ty Remarks CYLINDER AND PISTON REMOVAL Preparation for removal Cylinder head Refer to “CYLINDER HEAD” section. Bolt (cylinder) Cylinder Gasket...
  • Page 150 CYLINDER AND PISTON REMOVAL POINTS Piston 1. Remove: Piston pin clips 1 Piston pin 2 Piston 3 NOTE: Put identification marks on each piston head for reference during reinstallation. Before removing each piston pin, deburr the clip groove and pin hole area. If the piston pin groove is deburred and the piston pin is still difficult to remove, use the piston pin puller 4.
  • Page 151 CYLINDER AND PISTON 95.00 ~ 95.01 mm Cylinder bore “C” (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 D or D – (Maximum D or D “R”...
  • Page 152 CYLINDER AND PISTON Piston ring 1. Measure: Ring side clearance Use a feeler gauge 1. Out of specification → Replace the pis- ton and rings as a set. NOTE: Clean carbon from the piston ring grooves and rings before measuring the side clearance. Side clearance: Standard <Limit>...
  • Page 153 CYLINDER AND PISTON Piston pin 1. Inspect: Piston pin Blue discoloration/grooves → Replace, then inspect the lubrication system. 2. Measure: Piston pin-to-piston clearance Measurement steps: Measure the outside diameter (piston pin) If out of specification, replace the piston pin. Outside diameter (piston pin): 17.991 ~ 18.000 mm (0.7083 ~ 0.7087 in) Measure the inside diameter (piston) b.
  • Page 154 CYLINDER AND PISTON 2. Position: Top ring 2nd ring Oil ring 45° Offset the piston ring end gaps as 135° 135° shown. a Top ring end b 2nd ring end c Oil ring end (upper) d Oil ring e Oil ring end (lower) 3.

  • Page 155: Clutch

    CLUTCH CLUTCH CLUTCH Extent of removal: 1 Push rod and push lever removal 2 Push pod 1 disassembly 3 Friction plate and clutch plate removal 4 Clutch housing removal Extent of removal Order Part name Q’ty Remarks CLUTCH REMOVAL Preparation for removal Drain the engine oil.
  • Page 156 CLUTCH Extent of removal Order Part name Q’ty Remarks Clutch plate Friction plate Use special tool. Look washer Refer to “REMOVAL POINTS”. Clutch boss Thrust washer Clutch housing Push lever 4 - 49...
  • Page 157 CLUTCH EC493000 REMOVAL POINTS EC483211 Clutch boss 1. Remove: Nut 1 Lock washer 2 Clutch boss 3 NOTE: Straighten the lock washer tab and use the clutch holding tool 4 to hold the clutch boss. Å ı Clutch holding tool: YM-91042/90890-04086 Å...
  • Page 158 CLUTCH EC484500 Friction plate 1. Measure: Friction plate thickness Out of specification → Replace friction plate as a set. Measure at all four points. Friction plate thickness: 2.92 ~ 3.08 mm (0.115 ~ 0.121 in) <Limit>: 2.8 mm (0.110 in) EC484600 Clutch plate 1.
  • Page 159 CLUTCH EC4A5000 ASSEMBLY AND INSTALLATION Push lever 1. Install: Push lever 1 Bolt (push lever) 10 Nm (1.0 m · kg, 7.2 ft · lb) NOTE: Apply the lithium soap base grease on the oil seal lip. Apply the engine oil on the push lever. Fit the seat plate 2 in the groove a of the push lever and tighten the bolt (seat plate).
  • Page 160 CLUTCH 3. Bend the lock washer 1 tab. 4. Install: Friction plate 1 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.
  • Page 161 CLUTCH 7. Install: Pressure plate 1 8. Install: Clutch spring Bolt (clutch spring) 8 Nm (0.8 m · kg, 5.8 ft · lb) NOTE: Tighten the bolts in stage, using a crisscross pattern. 9. Install: Gasket (clutch cover) 1 Dowel pin 2 10.

  • Page 162: Oil Filter, Water Pump And Crankcase Cover (Right)

    OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) Extent of removal: 1 Oil filter removal 2 Water pump removal 3 Crankcase cover (right) removal Extent of removal Order Part name...
  • Page 163 OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) Extent of removal Order Part name Q’ty Remarks Oil hose Kick starter Crankcase cover (right) Gasket Dowel pin/O-ring Impeller Plain washer Impeller shaft Refer to “REMOVAL POINTS”. Oil seal 1 Oil seal 2 Bearing 4 - 56...
  • Page 164 OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) REMOVAL POINTS EC4G3110 Impeller shaft 1. Remove: Impeller 1 Plain washer 2 Impeller shaft 3 NOTE: Hold the impeller shaft on its width across the flats a with spanners, etc. and remove the impeller.
  • Page 165 OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) EC4H4600 Bearing 1. Inspect: Bearing Rotate inner race with a finger. Rough spot/seizure → Replace. EC444400 Oil seal 1. Inspect: Oil seal Wear/damage → Replace. ASSEMBLY AND INSTALLATION EC4G5110 Oil seal 1. Install: Oil seal 1 NOTE: Apply the lithium soap base grease on the oil...
  • Page 166 OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) EC4G5220 Impeller shaft 1. Install: Impeller shaft 1 Plain washer 2 Impeller 3 14 Nm (1.4 m · kg, 10 ft · lb) NOTE: Take care so that the oil seal lip is not dam- aged or the spring does not slip off its posi- tion.
  • Page 167 OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) Kick crank 1. Install: Kick starter 1 Plain washer Bolt (kick starter) 33 Nm (3.3 m · kg, 24 ft · lb) NOTE: Install the kick starter so that the kick starter is as vertical as possible with the distance a between the kick starter and the frame being 5 mm (0.20 in) or more.
  • Page 168 OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT) 2. Install: Water pump housing 1 Bolt (water pump housing) 2 10 Nm (1.0 m · kg, 7.2 ft · lb) Plain washer 3 Coolant drain bolt 4 10 Nm (1.0 m · kg, 7.2 ft · lb) 3.

  • Page 169: Balancer

    BALANCER BALANCER BALANCER Extent of removal: 1 Balancer drive gear 2 Balancer Extent of removal Order Part name Q’ty Remarks BALANCER REMOVAL Preparation for removal Clutch housing Refer to “CLUTCH” section. Crankcase cover (right) Refer to “OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)”...
  • Page 170 BALANCER REMOVAL POINTS Balancer drive gear and balancer driven gear 1. Straighten the lock washer tab. 2. Loosen: Nut (primary drive gear) 1 Nut (balancer) 2 NOTE: Place an aluminum plate a between the teeth of the balancer drive gear 3 and driven gear Balancer 1.
  • Page 171 BALANCER ASSEMBLY AND INSTALLATION Balancer, balancer drive gear and balancer driven gear 1. Install: Balancer 1 NOTE: When installing the balancer shaft, align the center of the balancer shaft weight a along the line connecting the centers of the crank- shaft and balancer shaft.

  • Page 172: Oil Pump

    OIL PUMP OIL PUMP OIL PUMP Extent of removal: 1 Oil pump removal 2 Oil pump disassembly Extent of removal Order Part name Q’ty Remarks OIL PUMP REMOVAL AND DIS- ASSEMBLY Preparation for removal Clutch housing Refer to “CLUTCH” section. Crankcase cover (right) Refer to “OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)”...
  • Page 173 OIL PUMP Extent of removal Order Part name Q’ty Remarks Washer Oil pump drive shaft Rotor housing 4 - 66...
  • Page 174 OIL PUMP INSPECTION Oil pump 1. Inspect: Oil pump drive gear Oil pump driven gear Rotor housing Oil pump cover Cracks/wear/damage → Replace. 2. Measure: Tip clearance a Between the inner rotor 1 and the outer rotor 2. Tip clearance b Between the outer rotor 2 and the rotor housing 3.
  • Page 175 OIL PUMP 2. Install: Outer rotor 1 1 NOTE: Apply the engine oil on the outer rotor 1. 3. Install: Oil pump cover 1 Screw (oil pump cover) 2 2 Nm (0.2 m · kg, 1.4 ft · lb) Pin 3 Inner rotor 2 4 Circlip 5 NOTE:...

  • Page 176: Kick Axle And Shift Shaft

    KICK AXLE AND SHIFT SHAFT KICK AXLE AND SHIFT SHAFT KICK AXLE AND SHIFT SHAFT Extent of removal: 1 Kick axle removal 2 Kick axle disassembly 3 Shift shaft removal 4 Segment removal Extent of removal Order Part name Q’ty Remarks KICK AXLE AND SHIFT SHAFT REMOVAL...
  • Page 177 KICK AXLE AND SHIFT SHAFT Extent of removal Order Part name Q’ty Remarks Roller Shift guide Refer to “REMOVAL POINTS”. Shift lever assembly Shift lever Pawl Pawl pin Spring Bolt (stopper lever) Stopper lever Torsion spring Segment Refer to “REMOVAL POINTS”. 4 - 70...
  • Page 178 KICK AXLE AND SHIFT SHAFT REMOVAL POINTS EC4B3101 Kick axle assembly 1. Remove: Kick axle assembly 1 NOTE: Unhook the torsion spring 2 from the hole a in the crankcase. EC4C3101 Shift guide and shift lever assembly 1. Remove: Bolt (shift guide) Shift guide 1 Shift lever assembly 2 NOTE:...
  • Page 179 KICK AXLE AND SHIFT SHAFT EC4B4400 Shift shaft 1. Inspect: Shift shaft 1 Bend/damage → Replace. Spring 2 Broken → Replace. EC4C4100 Shift guide and shift lever assembly 1. Inspect: Shift guide 1 Shift lever 2 Pawl 3 Pawl pin 4 Spring 5 Wear/damage →...
  • Page 180 KICK AXLE AND SHIFT SHAFT EC4B5111 Stopper lever 1. Install: Torsion spring 1 Stopper lever 2 Bolt (stopper lever) 3 10 Nm (1.0 m · kg, 7.2 ft · lb) NOTE: Align the stopper lever roller with the slot on segment.
  • Page 181 KICK AXLE AND SHIFT SHAFT EC4C5301 Shift shaft 1. Install: Roller 1 Collar 2 Torsion spring 3 Shift shaft 4 NOTE: Apply the engine oil on the roller and shift shaft. 2. Install: Shift pedal 1 Bolt (shift pedal) 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...
  • Page 182 KICK AXLE AND SHIFT SHAFT 3. Install: Spring guide 1 NOTE: Slide the spring guide into the kick axle, make sure the groove a in the spring guide fits on the stopper of the torsion spring. 4. Install: Kick axle assembly 1 Plain washer 2 NOTE: Apply the molybdenum disulfide grease on...

  • Page 183: Cdi Magneto

    CDI MAGNETO EC4L0000 CDI MAGNETO Extent of removal: CDI magneto removal Extent of removal Order Part name Q’ty Remarks CDI MAGNETO REMOVAL Preparation for removal Seat and fuel tank Refer to “SAET, FUEL TANK AND SIDE COVERS” section. Bolt [radiator (left)] Refer to “RADIATOR”...
  • Page 184 CDI MAGNETO EC4L3000 REMOVAL POINTS EC4L3101 Rotor 1. Remove: Nut (rotor) 1 Plain washer Use the rotor holding tool 2. Rotor holding tool: YU-1235/90890-01235 2. Remove: Rotor 1 Use the flywheel puller 2. Flywheel puller: YM-1189/90890-01189 NOTE: When installing the flywheel puller, turn it counterclockwise.
  • Page 185 Apply the sealant to the grommet of the CDI magneto lead. Tighten the screws using the T30 bit. ® Quick gasket ACC-QUICK-GS-KT YAMAHA Bond No. 1215: 90890-85505 2. Install: Woodruff key 1 Rotor 2 NOTE: Clean the tapered portions of the crankshaft and rotor.
  • Page 186 CDI MAGNETO 4. Connect: CDI magneto lead Refer to “CABLE ROUTING DIA- GRAM” section in the CHAPTER 2. 5. Install: Gasket [crankcase cover (left)] Crankcase cover (left) 1 Hose holder (cylinder head breather hose) 2 Bolt [crankcase cover (left)] 10 Nm (1.0 m · kg, 7.2 ft · lb) NOTE: Tighten the bolts in stage, using a crisscross pattern.

  • Page 187: Engine Removal

    ENGINE REMOVAL EC4M0000 ENGINE REMOVAL Extent of removal Order Part name Q’ty Remarks ENGINE REMOVAL Preparation for removal Hold the machine by placing the WARNING suitable stand under the frame. Support the machine securely so there is no danger of it falling over. Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE COVERS”...
  • Page 188 ENGINE REMOVAL Extent of removal: 1 Engine removal Extent of removal Order Part name Q’ty Remarks Engine skid plate (front) Neutral switch Oil hose Chain cover Nut (drive sprocket) Lock washer Refer to “REMOVAL POINTS”. Drive sprocket Clip Bolt (brake pedal) Brake pedal Engine upper bracket (right) Engine upper bracket (left)
  • Page 189 ENGINE REMOVAL EC4M3000 REMOVAL POINTS EC4F3100 Drive sprocket 1. Remove: Nut (drive sprocket) 1 Lock washer 2 NOTE: Straighten the lock washer tab. Loosen the nut while applying the rear brake. 2. Remove: Drive sprocket 1 Drive chain 2 NOTE: Remove the drive sprocket together with the drive chain.
  • Page 190 ENGINE REMOVAL EC4M5000 ASSEMBLY AND INSTALLATION Engine installation 1. Install: Engine 1 Install the engine from right side. Pivot shaft 2 85 Nm (8.5 m · kg, 61 ft · lb) Engine mounting bolt (lower) 3 69 Nm (6.9 m · kg, 50 ft · lb) Engine lower bracket 4 Bolt (engine bracket) 5 34 Nm (3.4 m ·...
  • Page 191 ENGINE REMOVAL 2. Install: Lock washer 1 Nut (drive sprocket) 2 75 Nm (7.5 m · kg, 54 ft · lb) NOTE: Tighten the nut while applying the rear brake. 3. Bend the lock washer tab to lock the nut. 4.

  • Page 192: Crankcase And Crankshaft

    CRANKCASE AND CRANKSHAFT CRANKCASE AND CRANKSHAFT CRANKCASE AND CRANKSHAFT Extent of removal: 1 Crankcase separation 2 Crankshaft removal Extent of removal Order Part name Q’ty Remarks CRANKCASE SEPARATION Preparation for removal Engine Refer to “ENGINE REMOVAL” section. Piston Refer to “CYLINDER AND PISTON” sec- tion.
  • Page 193 CRANKCASE AND CRANKSHAFT Extent of removal Order Part name Q’ty Remarks Oil strainer Oil delivery pipe 2 Crankshaft Use special tool. Refer to “REMOVAL POINTS”. 4 - 86...

  • Page 194: Transmission, Shift Cam And Shift Fork

    CRANKCASE AND CRANKSHAFT CRANKCASE BEARING Extent of removal: 1 Crankcase bearing removal Extent of removal Order Part name Q’ty Remarks CRANKCASE BEARING REMOVAL Preparation for removal Transmission Refer to “TRANSMISSION, SHIFT Shift cam and shift fork CAM AND SHIFT FORK” section. Oil seal Bearing Refer to “REMOVAL POINTS”.
  • Page 195 CRANKCASE AND CRANKSHAFT REMOVAL POINTS Crankcase 1. Separate: Crankcase (right) Crankcase (left) Separation steps: Remove the crankcase bolts, hose guide and clutch cable holder. NOTE: Loosen each bolt 1/4 of a turn at a time and after all the bolts are loosened, remove them.
  • Page 196 CRANKCASE AND CRANKSHAFT Crankshaft 1. Remove: Crankshaft 1 Use the crankcase separating tool 2. Crankcase separating tool: YU-1135-A/90890-01135 CAUTION: Do not use a hammer to drive out the crankshaft. Crankshaft bearing 1. Remove: Bearing 1 NOTE: Remove the bearing from the crankcase by pressing its inner race.
  • Page 197 CRANKCASE AND CRANKSHAFT EC4N4201 Crankshaft 1. Measure: Runout limit a Small end free play limit b Connecting rod big end side clearance Crank width d Out of specification → Replace. Use the dial gauge and a thickness gauge. Dial gauge and stand: YU-3097/90890-01252 Standard <Limit>...
  • Page 198 CRANKCASE AND CRANKSHAFT EC4N5000 ASSEMBLY AND INSTALLATION Crankshaft bearing 1. Install: Bearing Bearing stopper Bolt (bearing stopper) 10 Nm (1.0 m · kg, 7.2 ft · lb) Screw (bearing stopper) 10 Nm (1.0 m · kg, 7.2 ft · lb) Screw [bearing stopper (crankshaft)] 1 10 Nm (1.0 m ·...
  • Page 199 10 Nm (1.0 m · kg, 7.2 ft · lb) 4. Apply: Sealant On the crankcase (right) 1. ® Quick gasket ACC-QUICK-GS-KT YAMAHA Bond No. 1215: 90890-85505 NOTE: Clean the contacting surface of crankcase (left and right) before applying the sealant. 4 - 92...
  • Page 200 CRANKCASE AND CRANKSHAFT 5. Install: Dowel pin 1 O-ring 2 Crankcase (right) To crankcase (left). NOTE: Fit the crankcase (right) onto the crankcase (left). Tap lightly on the case with soft ham- mer. When installing the crankcase, the connect- ing rod should be positioned at TDC (top dead center).
  • Page 201 TRANSMISSION, SHIFT CAM AND SHIFT FORK TRANSMISSION, SHIFT CAM AND SHIFT FORK TRANSMISSION, SHIFT CAM AND SHIFT FORK Extent of removal: 1 Shift fork, shift cam, main axle and drive axle removal Extent of removal Order Part name Q’ty Remarks TRANSMISSION, SHIFT CAM AND SHIFT FORK REMOVAL Preparation for removal...
  • Page 202 TRANSMISSION, SHIFT CAM AND SHIFT FORK EC4H3000 REMOVAL POINTS Shift fork, shaft cam and transmission 1. Remove: Shift forks Shift cam Main axle Drive axle NOTE: Tap lightly on the transmission drive axle and shift cam with a soft hammer to remove. Remove assembly carefully.
  • Page 203 TRANSMISSION, SHIFT CAM AND SHIFT FORK EC4H4801 Shift fork, shift cam and segment 1. Inspect: Shift fork 1 Wear/damage/scratches → Replace. 2. Inspect: Shift cam 1 Segment 2 Bend/wear/damage → Replace. 3. Check: Shift fork movement Unsmooth operation → Replace shift fork.
  • Page 204 TRANSMISSION, SHIFT CAM AND SHIFT FORK 2. Install: 2nd wheel gear (25T) 1 3rd wheel gear (23T) 2 4th wheel gear (21T) 3 1st wheel gear (27T) 4 O-ring 5 To drive axle 6. NOTE: Apply the molybdenum disulfide oil on the 1st, 2nd and 3rd wheel gears inner circum- ference and on the end surface.
  • Page 205 TRANSMISSION, SHIFT CAM AND SHIFT FORK 5. Install: Shift fork 1 (L) 1 Shift fork 2 (R) 2 Shift cam 3 To main axle and drive axle. NOTE: Apply the molybdenum disulfide oil on the shift fork grooves. Mesh the shift fork #1 (L) with the 3rd pinion gear 4 on the main axle.

  • Page 206: Chassis

    CHAS FRONT WHEEL AND REAR WHEEL EC500000 CHASSIS EC590000 FRONT WHEEL AND REAR WHEEL EC598000 FRONT WHEEL Extent of removal: 1 Front wheel removal 2 Wheel bearing removal 3 Brake disc removal Extent of removal Order Part name Q’ty Remarks FRONT WHEEL REMOVAL WARNING Hold the machine by placing the...
  • Page 207 CHAS FRONT WHEEL AND REAR WHEEL EC598100 REAR WHEEL Extent of removal: 1 Rear wheel removal 2 Wheel bearing removal 3 Brake disc removal Extent of removal Order Part name Q’ty Remarks REAR WHEEL REMOVAL WARNING Preparation for removal Hold the machine by placing the Support the machine securely so there is no danger of it falling over.
  • Page 208 CHAS FRONT WHEEL AND REAR WHEEL EC593000 REMOVAL POINTS EC523101 Rear wheel 1. Remove: Wheel 1 NOTE: Push the wheel forward and remove the drive chain 2 . EC513201 Wheel bearing (if necessary) 1. Remove: Bearing 1 NOTE: Remove the bearing using a general bearing puller 2 .
  • Page 209 CHAS FRONT WHEEL AND REAR WHEEL EC514200 Wheel axle 1. Measure: Wheel axle bends Out of specification → Replace. Use the dial gauge 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.
  • Page 210 CHAS FRONT WHEEL AND REAR WHEEL EC595000 ASSEMBLY AND INSTALLATION Front wheel 1. Install: Bearing (left) 1 Spacer 2 Bearing (right) 3 Oil seal 4 NOTE: Apply the lithium soap base grease on the bearing and oil seal lip when installing. Use a socket that matches the outside diam- eter of the race of the bearing.
  • Page 211 CHAS FRONT WHEEL AND REAR WHEEL 5. Install: Wheel axle 1 NOTE: Apply the lithium soap base grease on the wheel axle. 6. Install: Nut (wheel axle) 1 105 Nm (10.5 m · kg, 75 ft · lb) 7. Tighten: Bolt (axle holder) 1 23 Nm (2.3 m ·...
  • Page 212 CHAS FRONT WHEEL AND REAR WHEEL 9. Install: Hose cover 1 Plain washer 2 Bolt [hose cover (M8)] 3 16 Nm (1.6 m · kg, 11 ft · lb) Bolt [hose cover (M6)] 4 7 Nm (0.7 m · kg, 5.1 ft · lb) Rear wheel 1.
  • Page 213 CHAS FRONT WHEEL AND REAR WHEEL 3. Install: Driven sprocket 1 Bolt (driven sprocket) 2 Plain washer (driven sprocket) 3 Nut (driven sprocket) 4 42 Nm (4.2 m · kg, 30 ft · lb) NOTE: Tighten the nuts in stage, using a crisscross pattern.
  • Page 214 CHAS FRONT WHEEL AND REAR WHEEL 8. Install: Chain puller (right) 1 Plain washer 2 Nut (wheel axle) 3 NOTE: Temporarily tighten the nut (wheel axle) at this point. 9. Adjust: Drive chain slack a Drive chain slack: 40 ~ 50 mm (1.6 ~ 2.0 in) Refer “DRIVE CHAIN...

  • Page 215: Front Brake And Rear Brake

    CHAS FRONT BRAKE AND REAR BRAKE EC5A0000 FRONT BRAKE AND REAR BRAKE EC5A8000 FRONT BRAKE Extent of removal: 1 Brake hose removal 2 Caliper removal 3 Master cylinder removal Extent of removal Order Part name Q’ty Remarks WARNING FRONT BRAKE REMOVAL Support the machine securely so there is no Hold the machine by placing the Preparation for removal...
  • Page 216 CHAS FRONT BRAKE AND REAR BRAKE EC5A8100 REAR BRAKE Extent of removal: 1 Master cylinder removal 2 Brake hose removal 3 Caliper removal Extent of removal Order Part name Q’ty Remarks REAR BRAKE REMOVAL WARNING Preparation for removal Hold the machine by placing the Support the machine securely so there is no suitable stand under the engine.
  • Page 217 CHAS FRONT BRAKE AND REAR BRAKE EC5A8200 CALIPER DISASSEMBLY Å Front ı Rear Extent of removal: 1 Front caliper disassembly 2 Rear caliper disassembly Extent of removal Order Part name Q’ty Remarks CALIPER DISASSEMBLY Pad pin Brake pad Pad support Caliper piston Refer to “REMOVAL POINTS”.
  • Page 218 CHAS FRONT BRAKE AND REAR BRAKE EC5A8300 MASTER CYLINDER DISASSEMBLY Å Front ı Rear Extent of removal: 1 Front master cylinder disassembly 2 Rear master cylinder disassembly Extent of removal Order Part name Q’ty Remarks MASTER CYLINDER DISAS- SEMBLY Master cylinder cap Diaphragm Master cylinder boot Circlip...
  • Page 219 CHAS FRONT BRAKE AND REAR BRAKE EC5A3000 Å REMOVAL POINTS Brake fluid 1. Remove: [Front] Master cylinder cap 1 [Rear] Master cylinder cap 1 Protector NOTE: Do not remove the diaphragm. ı Å Front ı Rear 2. Connect the transparent hose 2 to the bleed screw 1 and place a suitable con- tainer under its end.
  • Page 220 CHAS FRONT BRAKE AND REAR BRAKE EC533402 Å Piston seal kit 1. Remove: Dust seal 1 Piston seal 2 NOTE: Remove the piston seals and dust seals by pushing them with a finger. CAUTION: ACHTUNG: ı Never attempt to pry out piston seals and dust seals.
  • Page 221 CHAS FRONT BRAKE AND REAR BRAKE EC534214 Å ı Caliper 1. Inspect: Caliper cylinder inner surface a Wear/score marks → Replace caliper assembly. Å Front ı Rear 2. Inspect: Caliper piston 1 Wear/score marks → Replace caliper piston assembly. WARNING Replace the piston seals and dust seals 2 whenever a caliper is disassembled.
  • Page 222 CHAS FRONT BRAKE AND REAR BRAKE 2. Install: Å Piston seal 1 Dust seal 2 WARNING Always use new piston seals and dust seals. NOTE: Fit the piston seals and dust seals onto the slot on caliper correctly. ı Å Front ı...
  • Page 223 CHAS FRONT BRAKE AND REAR BRAKE 2. Install: Copper washer 1 Union bolt 2 30 Nm (3.0 m · kg, 22 ft · lb) WARNING Always use new copper washers. CAUTION: ACHTUNG: Install the brake hose so that its pipe por- tion a directs as shown and lightly touches the projection b on the caliper.
  • Page 224 CHAS FRONT BRAKE AND REAR BRAKE 2. Install: Disc cover 1 Bolt (disc cover) 2 7 Nm (0.7 m · kg, 5.1 ft · lb) 3. Install: Caliper 1 Rear wheel 2 Refer to “FRONT WHEEL AND REAR WHEEL” section. 4.
  • Page 225 CHAS FRONT BRAKE AND REAR BRAKE 3. Install: Å ı Spring 1 To master cylinder piston 2. NOTE: Install the spring at the smaller dia. side. Å Front ı Rear 4. Install: Å [Front] Master cylinder kit 1 Plain washer 2 Circlip 3 Master cylinder boot 4 To master cylinder 5.
  • Page 226 CHAS FRONT BRAKE AND REAR BRAKE 2. Install: Brake lever 1 Bolt (brake lever) 2 6 Nm (0.6 m · kg, 4.3 ft · lb) Nut (brake lever) 3 6 Nm (0.6 m · kg, 4.3 ft · lb) NOTE: Apply the lithium soap base grease on the brake lever sliding surface, bolt and contacting surface of the master cylinder piston.
  • Page 227 CHAS FRONT BRAKE AND REAR BRAKE 4. Install: Pin 1 Plain washer 2 Cotter pin 3 NOTE: After installing, check the brake pedal height. Refer to “REAR BRAKE ADJUSTMENT” sec- tion in the CHAPTER 3. Front brake hose 1. Install: Brake hose 1 10 Nm (1.0 m ·...
  • Page 228 CHAS FRONT BRAKE AND REAR BRAKE 4. Install: Copper washer 1 Brake hose 2 Union bolt 3 30 Nm (3.0 m · kg, 22 ft · lb) WARNING Always use new copper washers. CAUTION: ACHTUNG: Install the brake hose so that its pipe por- tion a directs as shown and lightly touches the projection b on the master cylinder.
  • Page 229 CHAS FRONT BRAKE AND REAR BRAKE 2. Install: Brake hose holder 1 Screw (brake hose holder) 2 1 Nm (0.1 m · kg, 0.7 ft · lb) CAUTION: ACHTUNG: After installing the brake hose holders, make sure the brake hose does not contact the spring (rear shock absorber).
  • Page 230 CHAS FRONT BRAKE AND REAR BRAKE 2. Air bleed: Brake system Refer “BRAKE SYSTEM BLEEDING” section in the CHAPTER 3. Inspect: Brake fluid level Fluid at lower level → Fill up. Refer “BRAKE FLUID LEVEL INSPECTION” section in the CHAP- TER 3.

  • Page 231: Front Fork

    CHAS FRONT FORK EC550000 FRONT FORK Extent of removal: 1 Front fork removal Extent of removal Order Part name Q’ty Remarks FRONT FORK REMOVAL WARNING Preparation for removal Hold the machine by placing the Support the machine securely so there is no suitable stand under the engine.
  • Page 232 CHAS FRONT FORK EC558000 FRONT FORK DISASSEMBLY Extent of removal: 1 Oil seal removal 2 Damper rod removal Extent of removal Order Part name Q’ty Remarks FRONT FORK DISASSEMBLY Cap bolt Refer to “REMOVAL POINTS”. Fork spring Drain the fork oil. Dust seal Stopper ring Refer to “REMOVAL POINTS”.
  • Page 233 CHAS FRONT FORK EC556000 HANDLING NOTE NOTE: The front fork requires careful attention. So it is recommended that the front fork be main- tained at the dealers. CAUTION: ACHTUNG: To prevent an accidental explosion of air, following instructions should observed: The front fork with a built-in piston rod has a very sophisticated internal con- struction and is particularly sensitive to...
  • Page 234 CHAS FRONT FORK EC553201 Inner tube 1. Remove: Dust seal 1 Stopper ring 2 Using slotted-head screwdriver. CAUTION: ACHTUNG: Take care not to scratch the inner tube. 2. Remove: Inner tube 1 Oil seal removal steps: Push in slowly a the inner tube just before it bottoms out and then pull it back quickly Repeat this step until the inner tube can be pulled out from the outer tube.
  • Page 235 CHAS FRONT FORK EC554200 Base valve 1. Inspect: Valve assembly 1 Wear/damage → Replace. O-ring 2 Damage → Replace. EC554400 Fork spring 1. Measure: Fork spring free length a Out of specification → Replace. Fork spring free length: Standard Limit 460 mm (18.1 in) 455 mm (17.9 in) EC554502...
  • Page 236 CHAS FRONT FORK EC554700 Cap bolt 1. Inspect: Cap bolt 1 O-ring 2 Air bleed screw 3 Wear/damage → Replace. EC555000 ASSEMBLY AND INSTALLATION Front fork assembly 1. Wash the all parts in a clean solvent. 2. Install: Damper rod 1 To inner tube 2.
  • Page 237 CHAS FRONT FORK 5. Install: Spring guide 1 Locknut 2 To damper rod 3. NOTE: Install the spring guide with its cut a facing upward. With its thread b facing upward, fully finger tighten the locknut onto the damper rod. 6.
  • Page 238 CHAS FRONT FORK 9. Install: Slide metal 1 Plain washer 2 To outer tube slot. NOTE: Press the slide metal into the outer tube with fork seal driver 3. Fork seal driver: YM-01442/90890-01442 10. Install: Oil seal 1 NOTE: Press the oil seal into the outer tube with fork seal driver 2.
  • Page 239 CHAS FRONT FORK 13. Check: Inner tube smooth movement Tightness/binding/rough spots → Repeat the steps 2 to 12. 14. Compress the front fork fully. 15. Fill: Front fork oil Until outer tube top surface with recom- mended fork oil 1. Recommended oil: Suspension oil “01”...
  • Page 240 CHAS FRONT FORK 19. Wait ten minutes until the air bubbles have been removed from the front fork, and the oil has dispense evenly in system before setting recommended oil level. NOTE: Fill with the fork oil up to the top end of the outer tube, or the fork oil will not spread over to every part of the front forks, thus making it impossible to obtain the correct level.
  • Page 241 CHAS FRONT FORK 21. Measure: Distance a Out of specification → Turn into the locknut. Distance a: 20 mm (0.79 in) or more Between damper rod 1 top and locknut 2 top. 22. Loosen: Rebound damping adjuster 1 NOTE: Loosen the rebound damping adjuster finger tight.
  • Page 242 CHAS FRONT FORK 26. Tighten: Cap bolt (locknut) 1 29 Nm (2.9 m · kg, 21 ft · lb) NOTE: While compressing the fork spring, set the thin type spanners 2 between the spacer 3 and spring guide 4. Hold the locknut 5 and tighten the cap bolt with specified torque.
  • Page 243 CHAS FRONT FORK 4. Tighten: Pinch bolt (handle crown) 1 23 Nm (2.3 m · kg, 17 ft · lb) Pinch bolt (under bracket) 2 20 Nm (2.0 m · kg, 14 ft · lb) CAUTION: ACHTUNG: Tighten the under bracket to specified torque.

  • Page 244: Handlebar

    CHAS HANDLEBAR EC5B0000 HANDLEBAR Extent of removal: 1 Handlebar removal Extent of removal Order Part name Q’ty Remarks HANDLEBAR REMOVAL Preparation for removal Number plate Remove the clamp portion only. Hot starter cable Disconnect at the lever side. Hot starter lever holder Clutch cable Disconnect at the lever side.
  • Page 245 CHAS HANDLEBAR EC5B3000 REMOVAL POINTS EC5B3100 Master cylinder 1. Remove: Master cylinder bracket 1 Master cylinder 2 CAUTION: ACHTUNG: Do not let the master cylinder hang on the brake hose. Keep the master cylinder cap side hori- zontal to prevent air from coming in. EC5B3200 Grip 1.
  • Page 246 CHAS HANDLEBAR EC5B5000 ASSEMBLY AND INSTALLATION Handlebar 1. Install: Handlebar 1 Handlebar holder 2 Bolt (handlebar holder) 3 28 Nm (2.8 m · kg, 20 ft · lb) NOTE: The upper handlebar holder should be installed with the punched mark a forward. First tighten the bolts on the front side of the handlebar holder, and then tighten the bolts on the rear side.
  • Page 247 CHAS HANDLEBAR 4. Install: Collar 1 Cover (grip cap) 2 Throttle grip 3 NOTE: Apply the lithium soap base grease on the throttle grip sliding surface. 5. Install: Throttle cables 1 To tube guide 2. NOTE: Apply the lithium soap base grease on the throttle cable end and tube guide cable wind- ing portion.
  • Page 248 CHAS HANDLEBAR 8. Install: Master cylinder 1 Master cylinder bracket 2 Bolt (master cylinder bracket) 3 9 Nm (0.9 m · kg, 6.5 ft · lb) NOTE: Install the bracket so that the arrow mark a faces upward. First tighten the bolt on the upper side of the master cylinder bracket, and then tighten the bolt on the lower side.
  • Page 249 CHAS HANDLEBAR 12. Clamp the clamp portion a of the num- ber plate to the handlebar. 13. Insert the end of the fuel breather hose 1 into the hole of the number plate. 5 - 44...

  • Page 250: Steering

    CHAS STEERING EC560000 STEERING Extent of removal: 1 Under bracket removal 2 Bearing removal Extent of removal Order Part name Q’ty Remarks STEERING REMOVAL WARNING Preparation for removal Hold the machine by placing the Support the machine securely so there is no suitable stand under the engine.
  • Page 251 CHAS STEERING EC563000 REMOVAL POINTS EC563202 Ring nut 1. Remove: Ring nut 1 Use the ring nut wrench 2. Ring nut wrench: YU-33975/90890-01403 WARNING Support the steering shaft so that it may not fall down. EC563300 Bearing (lower) 1. Remove: Bearing (lower) 1 Use the floor chisel 2.
  • Page 252 CHAS STEERING EC564101 Bearing and ball race 1. Wash the bearings and ball races with a solvent. 2. Inspect: Bearing 1 Ball race Pitting/damage → Replace bearings and ball races as a set. Install the bearing in the ball races. Spin the bearings by hand.
  • Page 253 CHAS STEERING 4. Install: Ring nut 1 7 Nm (0.7 m · kg, 5.1 ft · lb) Tighten the ring nut using the ring nut wrench 2. Refer to “STEERING HEAD INSPEC- TION AND ADJUSTMENT” section in the CHAPTER 3. 5.
  • Page 254 CHAS STEERING 10. Tighten: Pinch bolt (handle crown) 1 23 Nm (2.3 m · kg, 17 ft · lb) Pinch bolt (under bracket) 2 20 Nm (2.0 m · kg, 14 ft · lb) CAUTION: ACHTUNG: Tighten the under bracket to specified torque.

  • Page 255: Swingarm

    CHAS SWINGARM EC570000 SWINGARM Extent of removal: 1 Swingarm removal Extent of removal Order Part name Q’ty Remarks SWINGARM REMOVAL WARNING Preparation for removal Hold the machine by placing the Support the machine securely so there is no suitable stand under the engine. danger of it falling over.
  • Page 256 CHAS SWINGARM EC578000 SWINGARM DISASSEMBLY Extent of removal: 1 Swingarm disassembly 2 Connecting rod removal and disassembly 3 Relay arm removal and disassembly Extent of removal Order Part name Q’ty Remarks SWINGARM DISASSEMBLY Relay arm Connecting rod Collar Oil seal Thrust bearing Bush Oil seal...
  • Page 257 CHAS SWINGARM EC573000 REMOVAL POINTS EC573200 Bearing 1. Remove: Bearing 1 NOTE: Install the bearing by pressing its outer race. EC574010 INSPECTION Wash the bearings, bushes, collars, and cov- ers in a solvent. EC574111 Swingarm 1. Inspect: Bearing 1 Bush 2 Free play exists/unsmooth revolution/ rust →...
  • Page 258 CHAS SWINGARM EC574310 Connecting rod 1. Inspect: Bearing (polylube bearing) 1 Collar 2 Free play exists/unsmooth revolution/rust → Replace bearing and collar as a set. 2. Inspect: Bearing (polylube bearing) 1 Loss of solid lubrication → Replace. Oil seal 3 Damage →...
  • Page 259 CHAS SWINGARM 2. Install: Bearing 1 Oil seal 2 To relay arm. NOTE: Apply the molybdenum disulfide grease on the bearing when installing. Install the bearing by pressing it on the side having the manufacture’s marks or numbers. Installed depth of bearings a: 5 mm (0.20 in) 3.
  • Page 260 CHAS SWINGARM 3. Install: Collar 1 To connecting rod 2. NOTE: Apply the molybdenum disulfide grease on the collar and oil seal lips. 4. Install: Connecting rod 1 Bolt (connecting rod) 2 Plain washer 3 Nut (connecting rod) 4 80 Nm (8.0 m · kg, 58 ft · lb) To relay arm 5.
  • Page 261 CHAS SWINGARM 8. Install: 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 ·...
  • Page 262 CHAS SWINGARM 13. Install: Bolt [chain tensioner (lower)] 1 Plain washer 2 Collar 3 Chain tensioner 4 Nut [chain tensioner (lower)] 5 20 Nm (2.0 m · kg, 14 ft · lb) 14. Install: Chain support 1 Support cover 2 Bolt {chain support [r= 50 mm (1.97 in)]} Nut (chain support) 4 7 Nm (0.7 m ·...
  • Page 263 CHAS REAR SHOCK ABSORBER EC580000 REAR SHOCK ABSORBER Extent of removal: 1 Rear shock absorber removal 2 Rear shock absorber disassembly Extent of removal Order Part name Q’ty Remarks REAR SHOCK ABSORBER WARNING REMOVAL Support the machine securely so there is no Preparation for removal Hold the machine by placing the danger of it falling over.
  • Page 264 CHAS REAR SHOCK ABSORBER Extent of removal Order Part name Q’ty Remarks Spring guide (upper) Spring (rear shock absorber) Bearing Refer to “REMOVAL POINTS”. 5 - 59...
  • Page 265 1. Wear eye protection to prevent eye damage from escaping gas and/or metal chips. WARNING To dispose of a damaged or worn-out shock absorber, take the unit to your Yamaha dealer for this disposal procedure. 5 - 60...

  • Page 266: Rear Shock Absorber

    CHAS REAR SHOCK ABSORBER EC583000 REMOVAL POINTS EC583320 Bearing 1. Remove: Stopper ring (upper bearing) 1 NOTE: Press in the bearing while pressing its outer race and remove the stopper ring. 2. Remove: Upper bearing 1 NOTE: Remove the bearing by pressing its outer race. 3.
  • Page 267 CHAS REAR SHOCK ABSORBER EC585000 ASSEMBLY AND INSTALLATION EC585300 Bearing 1. Install: Upper bearing 1 NOTE: Install the bearing parallel until the stopper ring groove appears by pressing its outer race. CAUTION: ACHTUNG: Do not apply the grease on the bearing outer race because it will wear the rear shock absorber surface on which the bear- ing is press fitted.
  • Page 268 CHAS REAR SHOCK ABSORBER 2. Tighten: Adjuster 1 3. Adjust: Spring length (installed) a Spring length (installed) a: Standard Extent of length adjustment 249 mm (9.80 in) 240.5 ~ 258.5 mm (9.47 ~ 10.18 in) *264 mm (10.39 in) *255.5 ~ 273.5 mm (10.06 ~ 10.77 in) * For EUROPE NOTE:...
  • Page 269 CHAS REAR SHOCK ABSORBER 2. Install: Bush 1 Collar 2 Dust seal 3 NOTE: Apply the molybdenum disulfide grease on the bearing. Apply the lithium soap base grease on the bush, collars and dust seals. Install the dust seals with their lips facing outward.

  • Page 270: Electrical Components And Wiring Diagram

    – ELEC ELECTRICAL COMPONENTS AND WIRING DIAGRAM EC600000 ELECTRICAL EC610000 ELECTRICAL COMPONENTS AND WIRING DIAGRAM EC611000 ELECTRICAL COMPONENTS 1 “ENGINE STOP” button COLOR CODE W .....White 2 TPS (throttle position sensor) B...... Black Y ......Yellow Br ....Brown 3 Neutral switch B/L ....Black/Blue G .....

  • Page 271: Map-Controlled Cdi Unit

    – ELEC MAP-CONTROLLED CDI UNIT MAP-CONTROLLED CDI UNIT 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.

  • Page 272: Ignition System

    – ELEC IGNITION SYSTEM EC620000 IGNITION SYSTEM INSPECTION STEPS 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. Spark *Clean or replace Spark gap test spark plug.
  • Page 273 – ELEC IGNITION SYSTEM SPARK GAP TEST Å 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. Ignition coil 3 Spark plug 4 Å...
  • Page 274 – ELEC IGNITION SYSTEM EC626002 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 Tester selector resistance position...
  • Page 275 – ELEC IGNITION SYSTEM 2. Inspect: Source coil 1 resistance Out of specification → Replace. Tester (+) lead → Brown lead 1 Tester (–) lead → Green lead 2 Source coil 1 Tester selector resistance position 720 ~ 1,080 Ω Ω...

  • Page 276: Tps (Throttle Position Sensor) System

    – ELEC TPS (THROTTLE POSITION SENSOR) SYSTEM EC690000 TPS (THROTTLE POSITION SENSOR) SYSTEM INSPECTION STEPS If the TPS will not operate, use the following inspection steps. No good Check entire ignition Repair or replace. system for connection. No good Check TPS. TPS coil Replace.
  • Page 277 – ELEC TPS (THROTTLE POSITION SENSOR) SYSTEM HANDLING NOTE CAUTION: 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. EC624000 COUPLERS AND LEADS CONNECTION INSPECTION...
  • Page 278 – ELEC TPS (THROTTLE POSITION SENSOR) SYSTEM 3. Inspect: TPS coil variable resistance Check that the resistance in increased as the throttle grip is moved from the full close position to the full open posi- tion. Out of specification → Replace. Tester (+) lead →...
  • Page 279 – ELEC TPS (THROTTLE POSITION SENSOR) SYSTEM 4. Adjust: Idle speed Adjustment steps: Attach the inductive tachometer (engine tachometer) to the high tension cord. Turn the throttle stop screw 1 until the specified idle speed. Refer to “IDLE SPEED ADJUSTMENT” section in the CHAPTER 3.
  • Page 280 – ELEC TPS (THROTTLE POSITION SENSOR) SYSTEM 8. Tighten: Screw (TPS) 1 9. Stop the engine. EC694000 TPS INPUT VOLTAGE INSPECTION 1. Disconnect the TPS coupler. 2. Start the engine. 3. Inspect: TPS input voltage Out of specification → Replace the CDI unit.

  • Page 281: Tuning

    T U N SETTING EC700000 TUNING EC710000 ENGINE Carburetor setting The air/fuel mixture will vary depending on atmospheric conditions. Therefore, it is nec- essary to take into consideration the air pres- sure, 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.
  • Page 282 T U N SETTING CAUTION: The carburetor is extremely sensitive to foreign matter (dirt, sand, water, etc.). During installation, do not allow foreign matter to get into the carburetor. Always handle the carburetor and its components carefully. Even slight scratches, bends or damage to carbure- tor parts may prevent the carburetor from functioning correctly.
  • Page 283 T U N SETTING Effects of the setting parts on the throttle valve opening Å Closed ı Fully open Å ı 1 Pilot screw/pilot jet 2 Throttle valve cutaway 3 Jet needle 4 Main jet Main system The FLATCR carburetor has a primary main jet.
  • Page 284 T U N SETTING Pilot system The FLATCR carburetor is manufactured with a pilot screw. The pilot screw adjustment ranges from fully closed throttle to 1/4 open throttle. Main jet adjustment The richness of the air-fuel mixture at full throt- tle can be set by changing the main jet 1.
  • Page 285 T U N SETTING 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.
  • Page 286 T U N SETTING Pilot jet adjustment The richness of the air-fuel mixture with the throttle open 1/4 or less can be set by adjust- ing the pilot jet 1. Standard pilot jet Effects of adjusting the pilot jet (reference) Å...
  • Page 287 T U N SETTING Jet needle adjustment The jet needle is adjusted by changing it. Standard jet needle NCVQ The tapered sections of all jet needles have the same starting positions, but the needles are available with different straight-portion diameters. <Example>...
  • Page 288 T U N SETTING Carburetor setting parts Part name Size Part number Main jet Rich #178 4MX-14943-93 #175 4MX-14943-42 #172 4MX-14943-92 #170 4MX-14943-41 #168 4MX-14943-91 (STD) #165 4MX-14943-40 #162 4MX-14943-90 #160 4MX-14943-39 #158 4MX-14943-89 #155 4MX-14943-38 Lean #152 4MX-14943-88 Pilot jet Rich 4MX-14948-07 4MX-14948-06...
  • Page 289 T U N SETTING Examples of carburetor setting depending on symptom Symptom Setting Checking Discoloration of spark plug → At full throttle Increase main jet calibration no. Hard breathing (Gradually) If tan color, it is in good condition. Shearing noise If cannot be corrected: Whitish spark plug Clogged float valve seat...

  • Page 290: Chassis

    T U N SETTING EC720000 CHASSIS EC71P002 Selection of the secondary reduction ratio (Sprocket) Secondary Number of driven sprocket teeth reduction = Number of drive sprocket teeth ratio Standard secondary 48/14 (3.429) reduction ratio *47/14 (3.357) * For EUROPE <Requirement for selection of secondary gear reduction ratio>...
  • Page 291 T U N SETTING EC72N000 Drive and driven sprockets setting parts Part name Size Part number Drive sprocket 1 (STD) 9383E-14215 Drive sprocket 2 5TA-25446-00 *(STD) 5ET-25447-00 (STD) 5NY-25448-00 5NY-25449-00 5NY-25450-00 5NY-25451-00 5NY-25452-00 * For EUROPE EC721002 Tire pressure Tire pressure should be adjust to suit the road surface condition of the circuit.
  • Page 292 T U N SETTING EC722011 Front fork setting The front fork setting should be made depend- ing on the rider’s feeling of an actual run and the circuit conditions. The front fork setting includes the following three factors: 1. Setting of air spring characteristics Change the fork oil level.
  • Page 293 T U N SETTING EC727020 Spring preload adjustment The spring preload is adjusted by installing the adjustment washer 1 between the fork spring 2 and damper rod 3. CAUTION: Do not install three or more adjustment washers for each front fork. WARNING Always adjust each front fork to the same setting.
  • Page 294 T U N SETTING 2. Use of stiff spring Generally a stiff spring gives a stiff riding feeling. Rebound damping tends to become weaker, resulting in lack of a sense of contact with the road surface or in a vibrating handlebar. To set a stiff spring: Change the rebound damping.
  • Page 295 T U N SETTING EC72P000 Front fork setting parts Adjustment washer 1 TYPE (thickness) PART NUMBER T = 2.3 mm (0.09 in) 4SS-23364-L0 Front fork spring 2 [Equal pitch spring] I.D. SPRING SPRING TYPE MARK RATE PART NUMBER (slits) SOFT 0.380 4SS-23141-10 0.390...
  • Page 296 T U N SETTING 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 fol- lowing two factors: 1. Setting of spring preload Change the set length of the spring.
  • Page 297 T U N SETTING 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.
  • Page 298 T U N SETTING CAUTION: When using a rear cushion other than cur- rently installed, use the one whose overall length a does not exceed the standard as it may result in faulty performance. Never use one whose overall length is greater than standard.
  • Page 299 T U N SETTING EC72Q000 Rear shock absorber setting parts Rear shock spring 1 [Equal pitch spring] I.D. SPRING SPRING SPRING TYPE COLOR/ FREE RATE PART NUMBER POINT LENGTH 5UN-22212-00 Brown/1 5UN-22212-10 Green/1 SOFT 5UN-22212-20 Red/1 5UN-22212-30 Black/1 5UN-22212-40 Blue/1 5UN-22212-50 Yellow/1 5UN-22212-60 Pink/1...

  • Page 300: Suspension Setting

    T U N SETTING EC72H002 Suspension setting Front fork 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. Before any change, set the rear shock absorber sunken length to the standard figure 90 ~ 100 mm (3.5 ~ 3.9 in).
  • Page 301 T U N SETTING 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.
  • Page 302 YAMAHA MOTOR CO., LTD. PRINTED ON RECYCLED PAPER PRINTED IN JAPAN 2002.06-2.9×1 CR 2500 SHINGAI IWATA SHIZUOKA JAPAN...

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