Page 1 OWNER’S SERVICE MANUAL WR250FR 5UM-28199-10 LIT-11626-16-48 www.PlanDeGraissage.org...
Page 2 www.PlanDeGraissage.org...
Page 3 WR250FR OWNER’S SERVICE MANUAL ©2002 by Yamaha Motor Corporation, U.S.A. 1st Edition, November 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-11626-16-48 www.PlanDeGraissage.org...
Page 4 EC020000 INTRODUCTION Congratulations on your purchase of a Yamaha WR 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.
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Page 6 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., •...
Page 11 ILLUSTRATED SYMBOLS (Refer to the illustration) Illustrated symbols 1 to 7 are designed as SPEC 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 7 Tuning –...
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Page 13 EC090000 INDEX GENERAL INFORMATION INFO SPECIFICATIONS SPEC REGULAR INSPECTION AND ADJUSTMENTS INSP ENGINE CHASSIS CHAS – ELECTRICAL ELEC TUNING www.PlanDeGraissage.org...
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 ............1-14 STARTING AND BREAK-IN ....1-15 TORQUE-CHECK POINTS ..... 1-19 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 .......... 4-22 CYLINDER HEAD ........4-31 VALVES AND VALVE SPRINGS ... 4-34 CYLINDER AND PISTON ....... 4-43 CLUTCH ..........
Page 16 CHAPTER 6 ELECTRICAL ELECTRICAL COMPONENTS AND WIRING DIAGRAM ........6-1 MAP-CONTROLLED CDI UNIT ....6-2 IGNITION SYSTEM ........6-3 ELECTRIC STARTING SYSTEM ....6-8 CHARGING SYSTEM ......6-17 THROTTLE POSITION SENSOR SYSTEM ..........6-19 LIGHTING SYSTEM ........ 6-24 CHAPTER 7 TUNING ENGINE .............
Page 17: General Information
DESCRIPTION INFO EC100000 GENERAL INFORMATION EC110000 DESCRIPTION 1 Clutch lever NOTE: 2 Hot starter lever • The machine you have purchased may differ 3 Engine stop switch slightly from those shown in the following. 4 Trip meter • Designs and specifications are subject to 5 Main switch 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 positive identification of the model you own. 2. If your machine is stolen, the authorities will need the number to search for and identify your machine.
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 disassembly. When washing the machine with high pres- sured water, cover the parts follows. • Silencer exhaust port •...
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 overhauled.
Page 21 IMPORTANT INFORMATION INFO EC136000 CIRCLIPS 1. All circlips should be inspected carefully before reassembly. Always replace piston pin clips after one use. Replace distorted circlips. When installing a circlip 1, make sure that the sharp-edged corner 2 is posi- tioned opposite to the thrust 3 it receives. See the sectional view.
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 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 SPECIAL TOOLS INFO Part number Tool name/How to use Illustration YM-01442, 90890-01442 Fork seal driver This tool is used when install the fork oil seal. YU-3112-C, 90890-03112 Pocket tester Use this tool to inspect the coil resistance, output voltage and amperage. YU-8036-B Inductive tachometer 90890-03113...
Page 25 Dynamic spark tester 90890-06754 Ignition checker This instrument is necessary for checking the ignition system components.  ACC-QUICK-GS-KT Quick gasket 90890-85505 YAMAHA Bond No. 1215 This sealant (Bond) is used for crankcase mating sur- face, etc. www.PlanDeGraissage.org 1 - 9...
Page 26: Control Functions
CONTROL FUNCTIONS INFO EC150000 CONTROL FUNCTIONS MAIN SWITCH Functions of the respective switch positions are as follows: The engine can be started only at this position. OFF: All electrical circuits are switched off. Main switch indicator light The main switch 1 is equipped with an indica- tor light 2 to avoid forgetting to turn it off.
Page 27 CONTROL FUNCTIONS INFO EC152000 CLUTCH LEVER The clutch lever 1 is located on the left han- dlebar; it disengages or engages the clutch. Pull the clutch lever to the handlebar to disen- gage the clutch, and release the lever to engage the clutch.
Page 28 CONTROL FUNCTIONS INFO EC157000 REAR BRAKE PEDAL The rear brake pedal 1 is located on the right side of the machine. Press down on the brake pedal to activate the rear brake. FUEL COCK The fuel cock supplies fuel from the tank to carburetor and also filters the fuel.
Page 29 CONTROL FUNCTIONS INFO LIGHT SWITCH The light switch 1 is located on the handlebar. EC15F000 VALVE JOINT This valve joint 1 prevents fuel from flowing out and is installed to the fuel tank breather hose. CAUTION: In this installation, make sure the arrow faces the fuel tank and also downward.
Page 30: 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 31: 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: •...
Page 32 STARTING AND BREAK-IN INFO NOTE: If the engine fails to start by pushing the start switch, release the switch, wait a few seconds, and then try again. Each starting attempt should be as short as possible to preserve the battery. Do not crank the engine more than 10 seconds on any one attempt.
Page 33 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 pushing the start switch or by kick- ing the kickstarter crank forcefully with a firm stroke.
Page 34 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 switch.
Page 35: Torque-Check Points
TORQUE-CHECK POINTS INFO TORQUE-CHECK POINTS Frame construction Frame to rear frame Combined seat and fuel 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 stem to Steering stem to frame Steering stem to upper bracket...
Page 36: Cleaning And Storage
CLEANING AND STORAGE INFO EC1B0000 CLEANING AND STORAGE EC1B1000 CLEANING Frequent cleaning of your machine will enhance its appearance, maintain good overall performance, and extend the life of many com- ponents. 1. Before washing the machine, block off the end of the exhaust pipe to prevent water from entering.
Page 37 CLEANING AND STORAGE INFO EC1B2001 STORAGE If your machine is to be stored for 60 days or more, some preventive measures must be taken to avoid deterioration. After cleaning the machine thoroughly, prepare it for storage as follows: 1. Drain the fuel tank, fuel lines, and the car- buretor float bowl.
Page 38: Specifications
SPEC GENERAL SPECIFICATIONS EC200000 SPECIFICATIONS EC211000 GENERAL SPECIFICATIONS Model name: WR250FR (USA) WR250F (EUROPE) WR250F(R) (CDN, AUS, NZ, ZA) Model code number: 5UM1 (USA) 5UM2 (EUROPE) 5UM4 (CDN, AUS, NZ, ZA) Dimensions: Overall length 2,165 mm (85.2 in) Overall width 827 mm (32.6 in) Overall height 1,303 mm (51.3 in)
Page 39 SPEC GENERAL SPECIFICATIONS Oil capacity: Engine oil Periodic oil change 1.2 L (1.06 Imp qt, 1.27 US qt) With oil filter replacement 1.3 L (1.14 Imp qt, 1.37 US qt) Total amount 1.4 L (1.23 Imp qt, 1.48 US qt) Coolant capacity (including all routes): 1.3 L (1.14 Imp qt, 1.37 US qt) Air filter:...
Page 40 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 41: Maintenance Specifications
SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Item Standard Limit Cylinder head: Warp limit ---- 0.05 mm (0.002 in) Cylinder: Bore size 77.00 ~ 77.01 mm ---- (3.0315 ~ 3.0319 in) Out of round limit ---- 0.05 mm (0.002 in) Camshaft: Drive method Chain drive (Left) ----...
Page 42 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Timing chain: Timing chain type/No. of links 92RH2010-114M/114 ---- Timing chain adjustment method Automatic ---- Valve, valve seat, valve guide: Valve clearance (cold) 0.10 ~ 0.15 mm ---- (0.0039 ~ 0.0059 in) 0.17 ~ 0.22 mm ---- (0.0067 ~ 0.0087 in) Valve dimensions:...
Page 43 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Stem runout limit ---- 0.01 mm (0.0004 in) Valve seat width 0.9 ~ 1.1 mm 1.6 mm (0.0354 ~ 0.0433 in) (0.0630 in) 0.9 ~ 1.1 mm 1.6 mm (0.0354 ~ 0.0433 in) (0.0630 in) Valve spring: Free length 37.81 mm (1.49 in)
Page 44 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Piston pin bore inside diameter 16.002 ~ 16.013 mm 16.043 mm (0.6300 ~ 0.6304 in) (0.6316 in) Piston pin outside diameter 15.991 ~ 16.000 mm 15.971 mm (0.6296 ~ 0.6299 in) (0.6288 in) Piston rings: Top ring: Type Barrel...
Page 45 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Clutch: Friction plate thickness 2.9 ~ 3.1 mm (0.114 ~ 0.122 in) 2.7 mm (0.106 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 46 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Lubrication system: Oil filter type Paper type ---- Oil pump type Trochoid type ---- Tip clearance 0.12 mm or less 0.20 mm (0.0047 in or less) (0.008 in) Side clearance 0.09 ~ 0.17 mm 0.24 mm (0.0035 ~ 0.0067 in) (0.009 in)
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 (stud bolt) M9 ×...
Page 48 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb M8 × 1.25 Silencer M8 × 1.25 Silencer clamp M6 × 1.0 Spark arrester (for USA) M6 × 1.0 Silencer end pipe (for USA) M6 × 1.0 Crankcase M6 ×...
Page 49 SPEC MAINTENANCE SPECIFICATIONS CHASSIS Item Standard Limit Steering system: Steering bearing type Taper roller bearing ---- Front suspension: USA, CDN EUROPE AUS, NZ, ZA 300 mm (11.8 in) ← ← Front fork travel 460 mm (18.1 in) ← ← Fork spring free length Spring rate, STD K = 4.31 N/mm K = 4.12 N/mm...
Page 50 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Wheel: USA, CDN, ZA EUROPE, AUS, NZ ← Front wheel type Spoke wheel ---- ← Rear wheel type Spoke wheel ---- 21 × 1.60/Aluminum ← Front rim size/material ---- 18 × 1.85/Aluminum 18 × 2.15/Aluminum ---- Rear rim size/material Rim runout limit: Radial...
Page 51 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb M8 × 1.25 Upper bracket and outer tube M8 × 1.25 Lower bracket and outer tube M24 × 1.0 Upper bracket and steering stem 14.5 M8 × 1.25 Handlebar upper holder and upper bracket M28 ×...
Page 52 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb Nipple (spoke) — M8 × 1.25 Rear wheel sprocket M6 × 1.0 Rear brake disc cover M6 × 1.0 Rear brake caliper protector M8 × 1.25 Drive chain puller adjust bolt and locknut Engine mounting: M10 ×...
Page 53 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part to be tightened Thread size Q’ty m·kg ft·lb M6 × 1.0 Headlight (left and right) M6 × 1.0 Headlight (lower) M6 × 1.0 Taillight M4 × 1.59 Taillight lead clamp and rear fender 0.05 0.36 M6 ×...
Page 54 248 ~ 372 Ω at 20 °C (68 °F) Pickup coil resistance (color) ---- (White – Red) CDI unit-model/manufacturer 5UM-00/YAMAHA (For USA) ---- 5UM-10/YAMAHA (Except for USA) ---- Ignition coil: Model/manufacturer 5UL-00/DENSO ---- Minimum spark gap 6 mm (0.24 in) ---- 0.08 ~ 0.10 Ω...
Page 55 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Starter relay: Model/manufacturer 2768090-A/JIDECO ---- Amperage rating 180 A ---- 4.2 ~ 4.6 Ω at 20 °C (68 °F) Coil winding resistance ---- Starting circuit cut-off relay: Model/manufacturer ACM33221 M06/MATSUSHITA ---- 75.69 ~ 92.51 Ω at 20 °C (68 °F) Coil winding resistance ---- Fuse (amperage ×...
Page 56: 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 57: Cable Routing Diagram
SPEC CABLE ROUTING DIAGRAM EC240000 CABLE ROUTING DIAGRAM 1 Fuel tank breather hose 9 Oil hose G Cable guide 2 Oil tank breather hose 0 Hose guide H Negative battery lead 3 Clamp A AC magneto lead I Light switch lead 4 Diode B Cylinder head breather hose J Brake hose...
Page 58 SPEC CABLE ROUTING DIAGRAM È Insert the fuel tank breather hose into the hole in Ë Fasten the wire harness, starter motor lead and the steering stem cap. negative battery lead so that the plastic locking tie É Pass the oil tank breather hose on the outside of ends do not contact the ignition coil lead.
Page 59 SPEC CABLE ROUTING DIAGRAM Î Fasten the wire harness at its white tape. Ó Fasten the neutral switch lead and oil hose Ï Fasten the wire harness, throttle position sensor together with the plastic locking ties and cut off the lead (in the wire harness), starter motor lead and tie ends.
Page 60 SPEC CABLE ROUTING DIAGRAM × Pass the cylinder head breather hose on the Ü Pass the wire harness, clutch cable and light inside of the radiator hose 1 and on the outside of switch lead through the cable guide. Ý Fasten the AC magneto lead, neutral switch lead the radiator pipe (radiator hose 4).
Page 61 SPEC CABLE ROUTING DIAGRAM 1 Hot starter cable 0 Clamp É Pass the throttle cables and 2 Cable guide A CDI unit lead hot starter cable between the 3 Throttle cable (return) B CDI unit radiator and frame, then under 4 Throttle cable (pull) C CDI unit band the radiator mounting boss.
Page 62 SPEC CABLE ROUTING DIAGRAM Ì Fasten the coolant reservoir breather hose and carburetor breather hoses together. Í Fasten the CDI unit lead. Î Insert the CDI unit band over the CDI unit stay as far as possible. Ï Fasten the rectifier/regulator lead to the rectifier/ regulator bracket with a plastic locking tie and cut off the tie end.
Page 63 SPEC CABLE ROUTING DIAGRAM 1 Brake master cylinder È Install the brake hose so that its pipe portion 2 Brake hose holder directs as shown and lightly touches the projection 3 Brake hose on the brake caliper. É Pass the brake hose into the brake hose holders. Ê...
Page 64 SPEC CABLE ROUTING DIAGRAM 1 Starter motor lead È Position the starter motor lead, negative battery 2 Negative battery lead lead and wire harness in the tank damper slit. 3 Wire harness É Fasten the wire harness. 4 Clamp Ê Do not allow the taillight lead to slacken. 5 Taillight lead Ë...
Page 65 SPEC CABLE ROUTING DIAGRAM 1 Throttle cable B Trip meter Ë Pass the start switch lead in 2 Brake hose C Main switch front of the main switch lead. 3 Clamp D Light switch Ì Fasten the start switch lead. 4 Light switch lead E Start switch lead Í...
Page 66: 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 third...
Page 67 INSP MAINTENANCE INTERVALS Every third Every fifth After Every As re- Item Remarks break-in race quired 500 km) 1,000 km) SHIFT FORK, SHIFT CAM, GUIDE BAR Inspect Inspect wear ROTOR NUT Retighten EXHAUST PIPE, SILENCER, PROTECTOR Inspect and retighten Clean Replace * Whichever comes first *SPARK ARRESTER...
Page 68 Retighten sprocket bolt Inspect bearings Replace bearings Lubricate Lithium base grease THROTTLE, CONTROL CABLE Yamaha cable lube or SAE 10W-30 motor oil Check routing and connection Inspect dirt and wear on Lubricate the throttle cable on the Inspect and clean (throttle cable) carburetor side.
Page 69: 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 70: Engine
ENGINE/COOLANT LEVEL INSPECTION/ INSP COOLANT REPLACEMENT EC350000 ENGINE 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 71 INSP COOLANT REPLACEMENT 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. Remove: • Seat Refer to “SEAT, FUEL TANK AND SIDE COVERS”...
Page 72 INSP COOLANT REPLACEMENT 9. Fill: • Radiator • Engine To specified level. Recommended coolant: High quality ethylene glycol anti-freeze containing anti-corrosion for aluminum engine Coolant 1 and water (soft water) 2 mixing ratio: 50%/50% Coolant capacity: 1.3 L (1.14 Imp qt, 1.37 US qt) CAUTION: •...
Page 73 RADIATOR CAP INSPECTION/ INSP RADIATOR CAP OPENING PRESSURE INSPECTION 12. Install: • Coolant reservoir cap 13. Start the engine and let it warm up for sev- eral minutes. 14. Turn off the engine and inspect the coolant level. Refer to “COOLANT LEVEL INSPECTION” section.
Page 74 COOLING SYSTEM INSPECTION/ INSP CLUTCH ADJUSTMENT 2. Apply the specified pressure. Radiator cap opening pressure: 110 kPa (1.1 kg/cm , 15.6 psi) 3. Inspect: • Pressure Impossible to maintain the specified pres- sure for 10 seconds → Replace. COOLING SYSTEM INSPECTION 1.
Page 75 INSP THROTTLE CABLE ADJUSTMENT 2. Adjust: • Clutch lever free play Clutch lever free play adjustment steps: • Loosen the locknuts 1. • Adjust the free play by changing their tight- ening position. • Tighten the locknuts. NOTE: • Make minute adjustment on the lever side using the adjuster 2.
Page 76 THROTTLE LUBRICATION/ INSP HOT STARTER LEVER ADJUSTMENT THROTTLE LUBRICATION 1. Remove: • Cover (throttle cable cap) 1 • Cover (grip cap) 2 • Throttle grip cap 3 2. Apply: • Lithium soap base grease On the throttle cable end a. 3.
Page 77 INSP AIR FILTER CLEANING AIR FILTER CLEANING NOTE: Proper air filter maintenance is the biggest key to preventing premature engine wear and damage. CAUTION: Never run the engine without the air filter element in place; this would allow dirt and dust to enter the engine and cause rapid wear and possible engine damage.
Page 78 INSP AIR FILTER CLEANING CAUTION: • Do not twist the element when squeezing the element. • Leaving too much of solvent in the ele- ment may result in poor starting. 5. Inspect: • Air filter element Damage → Replace. 6. Apply: •...
Page 79 INSP ENGINE OIL LEVEL INSPECTION ENGINE OIL LEVEL INSPECTION 1. Start the engine, warm it up for several minutes, and then turn off the engine and wait for five minutes. 2. Place the machine on a level place and hold it up on upright position by placing the suitable stand under the engine.
Page 80 INSP ENGINE OIL REPLACEMENT (Except for USA and CDN) Temp. ˚C Recommended oil: Refer to the following chart for 10W-30 selection of oils which are 10W-40 suited to the atmospheric 15W-40 temperatures. 20W-40 Recommended engine oil classi- 20W-50 fication: API STANDARD: API “SG”...
Page 81 INSP ENGINE OIL REPLACEMENT 4. Remove: • Oil tank cap 1 • Oil filler cap 2 • Frame oil drain bolt 3 • Crankcase oil drain bolt 4 • Oil filter element drain bolt 5 Drain the crankcase and oil tank (frame) of its oil.
Page 82 INSP ENGINE OIL REPLACEMENT 8. Install: • Copper washer 1 • Oil strainer (frame) 2 70 Nm (7.0 m · kg, 50 ft · lb) • Oil hose 3 • Bolt (oil hose) 4 10 Nm (1.0 m · kg, 7.2 ft · lb) •...
Page 83 OIL PRESSURE INSPECTION/ INSP PILOT SCREW ADJUSTMENT OIL PRESSURE INSPECTION 1. Check: • Oil pressure Checking steps: • Slightly loosen the oil pressure check bolt • Start the engine and keep it idling until oil starts to seep from the oil pressure check bolt.
Page 84 ENGINE IDLING SPEED ADJUSTMENT/ INSP VALVE CLEARANCE INSPECTION AND ADJUSTMENT ENGINE IDLING SPEED ADJUSTMENT 1. Start the engine and thoroughly warm it up. 2. Attach: • Inductive tachometer To spark plug lead. 3. Adjust: • Engine idling speed Adjustment steps: •...
Page 85 INSP VALVE CLEARANCE INSPECTION AND ADJUSTMENT 3. Remove: • Right radiator Refer to “RADIATOR” section in the CHAPTER 4. • Carburetor Refer to “CARBURETOR” section in the CHAPTER 4. • Spark plug • Upper engine bracket • Cylinder head cover Refer to “CAMSHAFTS”...
Page 86 INSP VALVE CLEARANCE INSPECTION AND ADJUSTMENT • Measure the valve clearance e using a feeler gauge 1. NOTE: Record the measured reading if the clear- ance is incorrect. 6. Adjust: • Valve clearance Adjustment steps: • Remove the camshaft (intake and exhaust). Refer to “CAMSHAFTS”...
Page 87 INSP VALVE CLEARANCE INSPECTION AND ADJUSTMENT NOTE: The thickness a of each pad is indicated in hundreths of millimeters on the pad upper surface. • Round off the last digit of the installed pad number to the nearest increment. Last digit of pad Rounded value number 0, 1 or 2...
Page 88 INSP VALVE CLEARANCE INSPECTION AND 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...
Page 89 INSP SPARK ARRESTER CLEANING (For USA) SPARK ARRESTER CLEANING (For USA) WARNING • Be sure the exhaust pipe and muffler are cool before cleaning the spark arrester. • Do not start the engine when cleaning the exhaust system. 1. Remove: •...
Page 90: 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. •...
Page 91 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 res- ervoir.
Page 92 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: •...
Page 93 INSP FRONT BRAKE PAD INSPECTION AND REPLACEMENT • Loosen the pad pin 2. • Remove the brake hose holder 3 and brake caliper 4 from the front fork. • Remove the pad pin and brake pads 5. • Connect the transparent hose 6 to the bleed screw 7 and place the suitable con- tainer under its end.
Page 94 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 to “BRAKE FLUID LEVEL INSPEC- TION” section. 4.
Page 95 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 brake caliper piston in.
Page 96 REAR BRAKE PAD INSULATOR INSPECTION/ INSP BRAKE FLUID LEVEL INSPECTION 3. Inspect: • Brake fluid level Refer to “BRAKE FLUID LEVEL INSPEC- TION” section. 4. Check: • Brake pedal operation A softy or spongy feeling → Bleed brake system. Refer to “BRAKE SYSTEM AIR BLEED- ING”...
Page 97 INSP SPROCKETS INSPECTION/DRIVE CHAIN INSPECTION SPROCKETS INSPECTION 1. Inspect: • Sprocket teeth a Excessive wear → Replace. NOTE: Replace the drive sprocket, rear wheel sprocket and drive chain as a set. DRIVE CHAIN INSPECTION 1. Remove: • Drive chain 1 NOTE: Remove the drive chain using a drive chain cutter 2.
Page 98 INSP DRIVE CHAIN INSPECTION 5. Check: • Drive chain stiffness a Clean and oil the drive chain and hold as illustrated. Stiff → Replace the drive chain. 6. Install: • Chain joint 1 • O-ring 2 • Drive chain 3 NOTE: When installing the drive chain, apply the lith- ium soap base grease on the chain joint and...
Page 99 INSP DRIVE CHAIN SLACK ADJUSTMENT DRIVE CHAIN SLACK ADJUSTMENT 1. Elevate the rear wheel by placing the suit- able stand under the engine. 2. Check: • Drive chain slack a Above the seal guard installation bolt. Out of specification → Adjust. Drive chain slack: 40 ~ 50 mm (1.6 ~ 2.0 in) NOTE:...
Page 100 FRONT FORK INSPECTION/ INSP FRONT FORK OIL SEAL AND DUST SEAL CLEANING • Tighten the axle nut while pushing down the drive chain. Axle nut: 125 Nm (12.5 m • kg, 90 ft • lb) • Tighten the locknuts. Locknut: 16 Nm (1.6 m •...
Page 101 FRONT FORK INTERNAL PRESSURE RELIEVING/FRONT INSP FORK REBOUND DAMPING FORCE ADJUSTMENT FRONT FORK INTERNAL PRESSURE RELIEVING NOTE: If the front fork initial movement feels stiff dur- ing a run, relieve the front fork internal pres- sure. 1. Elevate the front wheel by placing a suit- able stand under the engine.
Page 102 FRONT FORK COMPRESSION DAMPING FORCE INSP ADJUSTMENT • STANDARD POSITION: This is the position which is back by the spe- cific number of clicks from the fully turned-in position. Standard position: 9 clicks out * 5 clicks out * For EUROPE, AUS, NZ and ZA CAUTION: Do not force the adjuster past the minimum or maximum extent of adjustment.
Page 103 INSP REAR SHOCK ABSORBER INSPECTION • STANDARD POSITION: This is the position which is back by the spe- cific number of clicks from the fully turned-in position. Standard position: 14 clicks out * 12 clicks out * For EUROPE, AUS, NZ and ZA CAUTION: Do not force the adjuster past the minimum or maximum extent of adjustment.
Page 104 REAR SHOCK ABSORBER SPRING PRELOAD INSP ADJUSTMENT REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT 1. Elevate the rear wheel by placing the suit- able stand under the engine. 2. Remove: • Rear frame 3. Loosen: • Locknut 1 4. Adjust: • Spring preload By turning the adjuster 2.
Page 105 REAR SHOCK ABSORBER REBOUND DAMPING FORCE INSP 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 106 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 107 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 108 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. •...
Page 109 INSP STEERING HEAD INSPECTION AND ADJUSTMENT 2. Inspect: • Bearing free play Exist play → Replace. EC36U013 STEERING HEAD INSPECTION AND ADJUSTMENT 1. Elevate the front wheel by placing a suit- able stand under the engine. 2. Check: • Steering stem Grasp the bottom of the forks and gently rock the fork assembly back and forth.
Page 110 INSP STEERING HEAD INSPECTION AND ADJUSTMENT • Tighten the steering ring nut 3 using steering nut wrench 4. NOTE: Set the torque wrench to the steering nut wrench so that they form a right angle. Steering nut wrench: YU-33975/90890-01403 Steering ring nut (initial tightening): 38 Nm (3.8 m •...
Page 111 INSP LUBRICATION È Use Yamaha cable lube or equivalent on these LUBRICATION areas. To ensure smooth operation of all components, É Use SAE 10W-30 motor oil or suitable chain lubri- lubricate your machine during setup, after cants. break-in, and after every race.
Page 112: Electrical
ELECTRICAL/SPARK PLUG INSPECTION/ INSP IGNITION TIMING CHECK 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.
Page 113 INSP IGNITION TIMING CHECK 2. Attach: • Timing light • Inductive tachometer To the ignition coil lead (orange lead 1). 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 114 INSP BATTERY INSPECTION AND CHARGING BATTERY INSPECTION AND CHARGING WARNING Batteries generate explosive hydrogen gas and contain electrolyte which is made of poisonous and highly caustic sulfuric acid. Therefore, always follow these preventive measures: • Wear protective eye gear when handling or working near batteries.
Page 115 INSP BATTERY INSPECTION AND CHARGING NOTE: Since MF batteries are sealed, it is not possi- ble to check the charge state of the battery by measuring the specific gravity of the electro- lyte. Therefore, the charge of the battery has to be checked by measuring the voltage at the battery terminals.
Page 116 INSP BATTERY INSPECTION AND CHARGING 4. Measure: • Battery charge Measurement steps: • Connect a pocket tester 1 to the battery terminals. Tester positive probe → battery positive terminal Tester negative probe → battery negative terminal NOTE: • The charge state of an MF battery can be checked by measuring its open-circuit volt- age (i.e., the voltage when the positive ter- minal is disconnected).
Page 117 INSP BATTERY INSPECTION AND CHARGING 5. Charge: • Battery (refer to the appropriate charging method illustration) WARNING Do not quick charge a battery. CAUTION: • Never remove the MF battery sealing caps. • Do not use a high-rate battery charger since it forces a high-amperage current into the battery quickly and can cause battery overheating and battery plate...
Page 118 INSP BATTERY INSPECTION AND CHARGING Charging method using a variable voltage charger www.PlanDeGraissage.org 3 - 53...
Page 119 INSP BATTERY INSPECTION AND CHARGING Charging method using a constant voltage charger www.PlanDeGraissage.org 3 - 54...
Page 120 BATTERY REPLACEMENT 1. Replace: • Battery CAUTION: This battery is for YAMAHA WR250F. After filling the battery with electrolyte, either charge it for at least 3 hours at the amperage specified on the battery or let it sit for at least 15 hours before using it.
Page 121 INSP FUSE INSPECTION 2. Check: • Continuity Checking steps: • Remove the fuse 1. • Connect the pocket tester to the fuse and check the continuity. NOTE: Set the pocket tester selector to “Ω × 1”. Pocket tester: YU-3112-C/90890-03112 • If the pocket tester indicates “∞”, replace the fuse.
Page 122 REPLACING THE HEADLIGHT BULBS/ INSP ADJUSTING THE HEADLIGHT BEAMS REPLACING THE HEADLIGHT BULBS 1. Remove: • Headlight Refer to “SEAT, FUEL TANK AND SIDE COVERS” section in the CHAPTER 4. 2. Remove: • Headlight bulb holder cover 1 3. Detach: •...
Page 123: Seat, Fuel Tank And Side Covers
SEAT, FUEL TANK AND SIDE COVERS EC400000 ENGINE SEAT, FUEL TANK AND SIDE COVERS 1 Seat removal 2 Fuel tank removal Extent of removal: 3 Side covers removal 4 Headlight removal Extent of removal Order Part name Q’ty Remarks SEAT, FUEL TANK AND SIDE COVERS REMOVAL Preparation for removal Turn the fuel cock to “OFF”.
Page 124 SEAT, FUEL TANK AND SIDE COVERS REMOVAL POINTS Side cover 1. Remove: • Bolt (side cover) • Left side cover 1 • Right side cover 2 NOTE: Draw the side cover downward to remove it because its claws a are inserted in the air fil- ter case.
Page 125: Exhaust Pipe And Silencer
EXHAUST PIPE AND SILENCER EC4S0000 EXHAUST PIPE AND SILENCER È Except for USA 1 Silencer removal 2 Exhaust pipe removal Extent of removal: Extent of removal Order Part name Q’ty Remarks EXHAUST PIPE AND SILENCER REMOVAL Preparation for removal Right side cover Refer to “SEAT, FUEL TANK AND SIDE COVERS”...
Page 126 EXHAUST PIPE AND SILENCER INSPECTION Silencer and exhaust pipe 1. Inspect: • Gasket 1 Damage → Replace. ASSEMBLY AND INSTALLATION Silencer and exhaust pipe 1. Install: • Gasket • Exhaust pipe 1 • Nut (exhaust pipe) 2 13 Nm (1.3 m · kg, 9.4 ft · lb) •...
Page 127 RADIATOR EC450001 RADIATOR 1 Radiator removal Extent of 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, fuel tank and left side cover Refer to “SEAT, FUEL TANK AND SIDE COVERS”...
Page 128: Radiator
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 129 RADIATOR 3. Install: • Right radiator 1 • Bolt (right radiator) 2 10 Nm (1.0 m · kg, 7.2 ft · lb) • Radiator hose 3 3 Refer to “CABLE ROUTING DIAGRAM” section in the CHAPTER 2. 4. Install: • Left radiator 1 •...
Page 130: Carburetor
CARBURETOR CARBURETOR 4 Nm (0.4 m kg, 2.9 ft • • 2 Nm (0.2 m kg, 1.4 ft • • 11 Nm (1.1 m kg, 8.0 ft • • 4 Nm (0.4 m kg, 2.9 ft • • 3 Nm (0.3 m kg, 2.2 ft •...
Page 131 CARBURETOR EC468000 CARBURETOR DISASSEMBLY 1 Carburetor disassembly Extent of removal: Extent of removal Order Part name Q’ty Remarks CARBURETOR DISASSEMBLY Carburetor breather hose Valve lever housing cover Screw (throttle shaft) Throttle valve Needle holder Jet needle Accelerator pump cover Spring Diaphragm (accelerator pump) Air cut valve cover Spring (air cut valve)
Page 132 CARBURETOR Extent of removal Order Part name Q’ty Remarks Float pin Float Needle valve 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 www.PlanDeGraissage.org 4 - 10...
Page 133 CARBURETOR HANDLING NOTE CAUTION: Do not loosen the screws (throttle position sensor) 1 except when changing the throt- tle 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 opening, each machine’s pilot screw has been...
Page 134 CARBURETOR 2. Inspect: • Main jet 1 • Pilot jet 2 • Needle jet 3 • Starter jet 4 • Pilot air jet 5 • Leak jet 6 Damage → Replace. Contamination → Clean. NOTE: • Use a petroleum based solvent for cleaning. Blow out all passages and jets with com- pressed air.
Page 135 CARBURETOR 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 136 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 (accelerator pump) 2 • Accelerator pump cover 3 • O-ring 4 •...
Page 137 CARBURETOR 2. Install: • Pilot air jet 1 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.
Page 138 CARBURETOR 7. Install: • Spring 1 To throttle shaft 2. NOTE: Install the bigger hook a of the spring fits on the stopper b of the throttle shaft pulley. 8. Install: 1 2 3 • Throttle shaft assembly 1 • Washer (metal) 2 •...
Page 139 CARBURETOR 10. Install: • Starter jet 1 • Pilot jet 2 • Spacer 3 • Needle jet 4 • Main jet 5 11. Install: • Needle valve 1 • Float 2 • Float pin 3 NOTE: • After installing the needle valve to the float, install them to the carburetor.
Page 140 CARBURETOR 14. Install: • Diaphragm (air cut valve) 1 • Spring (air cut valve) 2 • O-ring 3 • Air cut valve cover 4 • Screw (air cut valve cover) 5 15. Install: • Diaphragm (accelerator pump) 1 • Spring 2 •...
Page 141 CARBURETOR 19. Install: • Carburetor breather hose 1 NOTE: Install the carburetor breather hoses to the carburetor so that the hoses do not bend near where they are installed. 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.
Page 142 CARBURETOR 3. Install: • Hot starter plunger 1 2 Nm (0.2 m · kg, 1.4 ft · lb) 4. Tighten: • Screw (air filter joint) 1 3 Nm (0.3 m · kg, 2.2 ft · lb) • Screw (carburetor joint) 2 3 Nm (0.3 m ·...
Page 143 CARBURETOR 9. Install: • Clamp 1 Refer to “CABLE ROUTING DIAGRAM” section in the CHAPTER 2. www.PlanDeGraissage.org 4 - 21...
Page 144: Camshafts
CAMSHAFTS CAMSHAFTS CYLINDER HEAD COVER 1 Cylinder head cover removal Extent of 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 145 CAMSHAFTS CAMSHAFTS 1 Camshaft removal Extent of removal: Extent of removal Order Part name Q’ty Remarks CAMSHAFTS REMOVAL Timing mark accessing screw Crankshaft end accessing screw Timing chain tensioner cap bolt Timing chain tensioner Refer to “REMOVAL POINTS”. Camshaft cap Clip Exhaust camshaft Intake camshaft...
Page 146 CAMSHAFTS REMOVAL POINTS Camshaft 1. Remove: • Timing mark accessing screw 1 • Crankshaft end accessing screw 2 2. Align: • T.D.C. mark With align mark. Checking steps: • Turn the crankshaft counterclockwise with a wrench. • Align the T.D.C. mark a on the rotor with the align mark b on the crankcase cover when piston is at T.D.C.
Page 147 CAMSHAFTS 5. Remove: • 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 lobe Pitting/scratches/blue discoloration → Replace. 2. Measure: •...
Page 148 CAMSHAFTS 4. Measure: • Camshaft-to-cap clearance Out of specification → Measure camshaft outside 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. 1 onto the ®...
Page 149 CAMSHAFTS Decompression system 1. Check: • Decompression system Checking steps: • Check that the decompression mecha- nism cam 1 moves smoothly. • Check that the decompression mechanism cam lever pin 2 projects from the camshaft. Timing chain tensioner 1. Check: •...
Page 150 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 punch mark c on the exhaust camshaft and the punch mark d on the intake camshaft must align with the cylinder head surface, as shown in the illustration.
Page 151 CAMSHAFTS • With the rod fully wound and the chain ten- sioner UP mark a facing upward, install the gasket 1 and the timing chain ten- sioner 2, and tighten the bolt 3 to the specified torque. Bolt (timing chain tensioner): 10 Nm (1.0 m •...
Page 152 NOTE: Apply the sealant on the cylinder head cover gasket. ® Quick gasket ACC-QUICK-GS-KT YAMAHA Bond No. 1215: 90890-85505 7. Install: • Oil tank breather hose • Cylinder head breather hose • Spark plug 13 Nm (1.3 m · kg, 9.4 ft · lb) www.PlanDeGraissage.org...
Page 153 CYLINDER HEAD CYLINDER HEAD 1 Cylinder head removal Extent of 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 154: Cylinder Head
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 damag- ing or scratching: • Spark plug threads • Valve seats 2. Inspect: •...
Page 155 CYLINDER HEAD ASSEMBLY AND INSTALLATION Cylinder head 1. Install: • Dowel pin 1 • Cylinder head gasket 2 • Timing chain guide (exhaust side) 3 • Cylinder head 4 NOTE: While pulling up the timing chain, install the timing chain guide (exhaust side) and cylinder head.
Page 156: Valves And Valve Springs
VALVES AND VALVE SPRINGS VALVES AND VALVE SPRINGS 1 Valve removal Extent of 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. Adjusting pad Refer to “REMOVAL POINTS”.
Page 157 VALVES AND VALVE SPRINGS REMOVAL POINTS Valve lifter and valve cotter 1. Remove: • Valve lifter 1 • Pad 2 NOTE: Identify each lifter 1 and pad 2 position very carefully so that they can be reinstalled in their original place. 2.
Page 158 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 159 VALVES AND VALVE SPRINGS Valve guide remover: Intake: 4.0 mm (0.16 in) YM-4111/90890-04111 Exhaust: 4.5 mm (0.18 in) YM-4116/90890-04116 Valve guide installer: Intake: 4.0 mm (0.16 in) YM-4112/90890-04112 Exhaust: 4.5 mm (0.18 in) YM-4117/90890-04117 Valve guide reamer: Intake: 4.0 mm (0.16 in) YM-4113/90890-04113 Exhaust: 4.5 mm (0.18 in) YM-4118/90890-04118...
Page 160 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.
Page 161 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 162 VALVES AND VALVE SPRINGS Valve spring 1. Measure: • Valve spring free length a Out of specification → Replace. Free length (valve spring): Intake: 37.81 mm (1.49 in) <Limit>: 35.9 mm (1.41 in) Exhaust: 37.54 mm (1.48 in) <Limit>: 35.7 mm (1.41 in) 2.
Page 163 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 Valve lifter mark b Cylinder head mark a (color) (color)
Page 164 VALVES AND VALVE SPRINGS 3. Install: • Valve cotter 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 165: Cylinder And Piston
CYLINDER AND PISTON CYLINDER AND PISTON 1 Cylinder removal 2 Piston removal Extent of 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 Piston pin clip Piston pin Use special tool.
Page 166 CYLINDER AND PISTON REMOVAL POINTS Piston and piston ring 1. Remove: • Piston pin clip 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.
Page 167 CYLINDER AND PISTON 77.00 ~ 77.01 mm Cylinder bore “C” (3.0315 ~ 3.0319 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 168 CYLINDER AND PISTON Piston ring 1. Measure: • Ring side clearance Use a feeler gauge 1. Out of specification → Replace the piston and rings as a set. NOTE: Clean carbon from the piston ring grooves and rings before measuring the side clearance. Side clearance: Standard <Limit>...
Page 169 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.
Page 170 CYLINDER AND PISTON 2. Position: • Top ring • 2nd ring • Oil ring 45˚ 135˚ 135˚ Offset the piston ring end gaps as shown. a Top ring end b 2nd ring end c Oil ring end (upper) d Oil ring e Oil ring end (lower) 3.
Page 171 CYLINDER AND PISTON 3. Install: • Cylinder gasket 1 • Cylinder 2 NOTE: Install the cylinder with one hand while com- pressing the piston rings with the other hand. CAUTION: • Pass the timing chain 3 through the tim- ing chain cavity. •...
Page 172: Clutch
CLUTCH EC4A0000 CLUTCH 1 Push rod 1, 2 and push lever shaft removal 2 Push pod 1 disassembly Extent of removal: 3 Friction plate and clutch plate removal 4 Primary driven gear removal Extent of removal Order Part name Q’ty Remarks CLUTCH REMOVAL Preparation for removal...
Page 173 CLUTCH Extent of removal Order Part name Q’ty Remarks Friction plate Clutch plate Cushion spring Seat plate Nut (clutch boss) Use special tool. Look washer Refer to “REMOVAL POINTS”. Clutch boss Thrust washer Primary driven gear Push lever shaft www.PlanDeGraissage.org 4 - 51...
Page 174 CLUTCH EC4A3000 REMOVAL POINTS 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. È É Clutch holding tool: YM-91042/90890-04086 È...
Page 175 CLUTCH Friction plate 1. Measure: • Friction plate thickness Out of specification → Replace friction plate as a set. Measure at all four points. Friction plate thickness: 2.9 ~ 3.1 mm (0.114 ~ 0.122 in) <Limit>: 2.7 mm (0.106 in) EC484600 Clutch plate 1.
Page 176 CLUTCH EC4A5000 ASSEMBLY AND INSTALLATION Push lever shaft 1. Install: • Push lever shaft 1 • Bolt (push lever shaft) 2 10 Nm (1.0 m · kg, 7.2 ft · lb) NOTE: • Apply the lithium soap base grease on the oil seal lip.
Page 177 CLUTCH 3. Bend the lock washer 1 tab. 4. Install: • Seat plate 1 • Cushion spring 2 NOTE: • Install the seat plate with its chamfered por- tion a facing the clutch boss 3. • Install the seat plate so that it is not caught on the step b.
Page 178 CLUTCH 7. Install: • Push rod 2 1 • Ball 2 • Push rod 1 3 NOTE: Apply the engine oil on the push rod 1, 2 and ball. 8. Install: • Pressure plate 1 9. Install: • Clutch spring 1 •...
Page 179: Oil Filter Element, Water Pump And Right Crankcase Cover
OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER 1 Oil filter element removal 2 Water pump removal Extent of removal: 3 Right crankcase cover removal Extent of removal Order Part name Q’ty Remarks OIL FILTER ELEMENT, WATER...
Page 180 OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER Extent of removal Order Part name Q’ty Remarks Water pump housing Oil delivery pipe Bolt (oil hose) Kickstarter crank Right crankcase cover Impeller Washer Impeller shaft Refer to “REMOVAL POINTS”. Oil seal Bearing www.PlanDeGraissage.org 4 - 58...
Page 181 OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER REMOVAL POINTS Impeller shaft 1. Remove: • Impeller 1 • 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 182 OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER EC444200 Impeller shaft 1. Inspect: • Impeller shaft 1 Bend/wear/damage → Replace. Fur deposits → Clean. EC444300 Impeller shaft gear 1. Inspect: • Gear teeth a Wear/damage → Replace. EC4H4600 Bearing 1.
Page 183 OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER 2. Install: • Bearing 1 NOTE: Install the bearing by pressing its outer race parallel. Impeller shaft 1. Install: • Impeller shaft 1 • Washer 2 • Impeller 3 14 Nm (1.4 m · kg, 10 ft · lb) NOTE: •...
Page 184 OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER 2. Install: • Right crankcase cover 1 • Bolt (right crankcase cover) 2 10 Nm (1.0 m · kg, 7.2 ft · lb) NOTE: • Apply the engine oil on the impeller shaft end.
Page 185 OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANKCASE COVER Water pump housing 1. Install: • Dowel pin 1 • O-ring 2 NOTE: Apply the lithium soap base grease on the O- ring. 2. Install: • Water pump housing 1 • Bolt (water pump housing) 2 10 Nm (1.0 m ·...
Page 186: Balancer
BALANCER BALANCER 1 Balancer shaft drive gear 2 Balancer shaft Extent of removal: Extent of removal Order Part name Q’ty Remarks BALANCER REMOVAL Preparation for removal Primary driven gear Refer to “CLUTCH” section. Right crankcase cover Refer to “OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANK- CASE COVER”...
Page 187 BALANCER REMOVAL POINTS Balancer shaft drive gear and balancer shaft driven gear 1. Straighten the lock washer tab. 2. Loosen: • Nut (primary drive gear) 1 • Nut (balancer shaft driven gear) 2 NOTE: Place an aluminum plate a between the teeth of the balancer shaft drive gear 3 and driven gear 4.
Page 188 BALANCER ASSEMBLY AND INSTALLATION Balancer shaft, balancer shaft drive gear and balancer shaft driven gear 1. Install: • Balancer shaft 1 NOTE: • Apply the engine oil on the bearing. • When installing the balancer shaft, align the center a of the balancer shaft weight along the line connecting the centers of the crank- shaft and balancer shaft.
Page 189: Oil Pump
OIL PUMP OIL PUMP 1 Oil pump removal 2 Oil pump disassembly Extent of removal: Extent of removal Order Part name Q’ty Remarks OIL PUMP REMOVAL AND DIS- ASSEMBLY Preparation for removal Primary driven gear Refer to “CLUTCH” section. Right crankcase cover Refer to “OIL FILTER ELEMENT, WATER PUMP AND RIGHT CRANK- CASE COVER”...
Page 190 OIL PUMP Extent of removal Order Part name Q’ty Remarks Dowel pin Washer Oil pump drive shaft Rotor housing www.PlanDeGraissage.org 4 - 68...
Page 191 OIL PUMP INSPECTION Oil pump 1. Inspect: • Oil pump drive gear 1 • Oil pump drive shaft 2 • Rotor housing 3 • Oil pump cover 4 Cracks/wear/damage → Replace. 2. Measure: • Tip clearance a (between the inner rotor 1 and outer rotor 2) •...
Page 192 OIL PUMP ASSEMBLY AND INSTALLATION Oil pump 1. Install: • Oil pump drive shaft 1 • Washer 2 • Dowel pin 3 • Inner rotor 1 4 NOTE: • Apply the engine oil on the oil pump drive shaft and inner rotor 1. •...
Page 193 OIL PUMP 4. Install: • Outer rotor 2 1 • Dowel pin 2 • Oil pump assembly 3 • Bolt (oil pump assembly) [L = 25 mm (0.94 in)] 4 10 Nm (1.0 m · kg, 7.2 ft · lb) •...
Page 194: Kick Shaft And Shift Shaft
KICK SHAFT AND SHIFT SHAFT KICK SHAFT AND SHIFT SHAFT 1 Kick shaft removal 2 Kick shaft disassembly Extent of removal: 3 Shift shaft removal 4 Segment removal Extent of removal Order Part name Q’ty Remarks KICK SHAFT AND SHIFT SHAFT REMOVAL Preparation for removal Oil pump...
Page 195 KICK SHAFT AND SHIFT SHAFT Extent of removal Order Part name Q’ty Remarks Torsion spring 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”. www.PlanDeGraissage.org 4 - 73...
Page 196 KICK SHAFT AND SHIFT SHAFT REMOVAL POINTS Kick shaft assembly 1. Remove: • Kick shaft 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) •...
Page 197 KICK SHAFT 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 •...
Page 198 KICK SHAFT 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 199 KICK SHAFT AND SHIFT SHAFT 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 Refer to “AC MAGNETO AND STARTER CLUTCH”...
Page 200 KICK SHAFT AND SHIFT SHAFT 3. Install: • Spring guide 1 NOTE: Slide the spring guide into the kick shaft, make sure the groove a in the spring guide fits on the stopper of the torsion spring. 4. Install: • Kick shaft assembly 1 •...
Page 201: Ac Magneto And Starter Clutch
AC MAGNETO AND STARTER CLUTCH AC MAGNETO AND STARTER CLUTCH 1 Starter clutch/wheel gear removal 2 Rotor removal Extent of removal: 3 Pickup coil/stator removal Extent of removal Order Part name Q’ty Remarks AC MAGNETO AND STATOR REMOVAL Preparation for removal Drain the engine oil.
Page 202 AC MAGNETO AND STARTER CLUTCH Extent of removal Order Part name Q’ty Remarks Nut (rotor) Rotor Use special tool. Refer to “REMOVAL POINTS”. Woodruff key Starter clutch Starter clutch drive gear Bearing Plain washer Idle gear plate Idle gear 2 Holder Pickup coil Stator...
Page 203 AC MAGNETO AND STARTER CLUTCH EC4L3000 REMOVAL POINTS Rotor 1. Remove: • Nut (rotor) 1 • Plain washer 2. Remove: • Rotor 1 Use the rotor puller 2. Rotor puller: YM-04141/90890-04141 EC4L4000 INSPECTION AC magneto 1. Inspect: • Rotor inner surface a •...
Page 204 AC MAGNETO AND STARTER CLUTCH 3. Check: • Starter clutch operation • Install the starter clutch drive gear 1 onto the starter clutch 2 and hold the starter clutch. • When turning the starter clutch drive gear counterclockwise É, the starter clutch and the starter clutch drive gear should engage.
Page 205 NOTE: Apply the sealant to the grommet of the AC magneto lead. ® Quick gasket ACC-QUICK-GS-KT YAMAHA Bond No. 1215: 90890-85505 3. Install: • Idle gear 2 1 • Dowel pin 2 NOTE: Apply the engine oil on the idle gear 2.
Page 206 AC MAGNETO AND STARTER CLUTCH 5. Install: • Plain washer 1 • Bearing 2 • Starter clutch drive gear 3 • Starter clutch 4 NOTE: Apply the engine oil on the plain washer, bear- ing and starter clutch drive gear inner circum- ference.
Page 207 AC MAGNETO AND STARTER CLUTCH 9. Install: • Shaft 1 • Bearing 2 • Idle gear 1 3 NOTE: Apply the engine oil on the shaft, bearing and idle gear inner circumference. 10. Install: • Cover (idle gear 1) 1 •...
Page 208: 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. Drain the engine oil.
Page 209 ENGINE REMOVAL 1 Engine removal Extent of removal: Extent of removal Order Part name Q’ty Remarks Ignition coil Disconnect the AC magneto lead. Starter motor lead Disconnect at the starter motor side. Negative battery lead Disconnect at the engine side. Right engine guard Neutral switch Drive chain sprocket cover...
Page 210 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 •...
Page 211 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) •...
Page 212 ENGINE REMOVAL Drive sprocket 1. Install: • Drive sprocket 1 • Drive chain 2 NOTE: Install the drive sprocket together with the drive chain. 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.
Page 213 ENGINE REMOVAL 2. Install: • Spring 1 • Pin 2 • O-ring 3 • Neutral switch 4 • Screw (neutral switch) 5 4 Nm (0.4 m · kg, 2.9 ft · lb) NOTE: Apply the lithium soap base grease on the O- ring.
Page 214: Crankcase And Crankshaft
CRANKCASE AND CRANKSHAFT CRANKCASE AND CRANKSHAFT 1 Crankcase separation 2 Crankshaft removal Extent of removal: Extent of removal Order Part name Q’ty Remarks CRANKCASE AND CRANK- SHAFT REMOVAL Preparation for removal Engine Refer to “ENGINE REMOVAL” section. Piston Refer to “CYLINDER AND PISTON” sec- tion.
Page 215 CRANKCASE AND CRANKSHAFT Extent of removal Order Part name Q’ty Remarks Bolt [L = 45 mm (1.77 in)] Bolt [L = 55 mm (2.17 in)] Bolt [L = 70 mm (2.76 in)] Hose guide Refer to “REMOVAL POINTS”. Clutch cable holder Right crankcase Left crankcase Oil strainer...
Page 216 CRANKCASE AND CRANKSHAFT CRANKCASE BEARING 1 Crankcase bearing removal Extent of 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 217 CRANKCASE AND CRANKSHAFT REMOVAL POINTS Crankcase 1. Separate: • Right crankcase • Left crankcase Separation steps: • Remove the crankcase bolts 1, hose guide 2 and clutch cable holder 3. NOTE: Loosen each bolt 1/4 of a turn at a time and after all the bolts are loosened, remove them.
Page 218 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. Crankcase bearing 1. Remove: • Bearing 1 NOTE: • Remove the bearing from the crankcase by pressing its inner race.
Page 219 CRANKCASE AND CRANKSHAFT EC4N4201 Crankshaft 1. Measure: • Runout limit a • Small end free play limit b • Connecting rod big end side clearance c • Crank width d Out of specification → Replace. Use the dial gauge and a thickness gauge.
Page 220 CRANKCASE AND CRANKSHAFT EC4N5000 ASSEMBLY AND INSTALLATION Crankcase 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) •...
Page 221 10 Nm (1.0 m · kg, 7.2 ft · lb) 4. Apply: • Sealant On the right crankcase 1. ® Quick gasket ACC-QUICK-GS-KT YAMAHA Bond No. 1215: 90890-85505 NOTE: Clean the contacting surface of left and right crankcase before applying the sealant. 5. Install: • Dowel pin 1 •...
Page 222 CRANKCASE AND CRANKSHAFT 6. Tighten: • Hose guide 1 • Clutch cable holder 2 • Bolt (crankcase) 3 12 Nm (1.2 m · kg, 8.7 ft · lb) NOTE: Tighten the crankcase tightening bolts in stage, using a crisscross pattern. 7.
Page 223: Transmission, Shift Cam And Shift Fork
TRANSMISSION, SHIFT CAM AND SHIFT FORK EC4H0000 TRANSMISSION, SHIFT CAM AND SHIFT FORK 1 Shift fork, shift cam, main axle and drive axle removal Extent of removal: Extent of removal Order Part name Q’ty Remarks TRANSMISSION, SHIFT CAM AND SHIFT FORK REMOVAL Preparation for removal Engine Refer to “ENGINE REMOVAL”...
Page 224 TRANSMISSION, SHIFT CAM AND SHIFT FORK EC4H3000 REMOVAL POINTS EC4H3230 Transmission 1. Remove: • Main axle 1 • Drive axle 2 • Shift cam • Shift fork 3 • Shift fork 2 • Shift fork 1 NOTE: • Remove assembly with the collar 3 installed to the crankcase.
Page 225 TRANSMISSION, SHIFT CAM AND SHIFT FORK EC4H4810 Shift fork, shift cam and segment 1. Inspect: • Shift fork 1 Wear/damage/scratches → Replace. 2. Inspect: • Shift cam 1 • Segment 2 Wear/damage → Replace. 3. Check: • Shift fork movement Unsmooth operation →...
Page 226 TRANSMISSION, SHIFT CAM AND SHIFT FORK 2. Install: • 2nd wheel gear (28T) 1 • 4th wheel gear (25T) 2 • 3rd wheel gear (28T) 3 • 5th wheel gear (22T) 4 • 1st wheel gear (31T) 5 • O-ring 6 To drive axle 7.
Page 227 TRANSMISSION, SHIFT CAM AND SHIFT FORK 5. Install: • Shift fork 1 (L) 1 • Shift fork 2 (C) 2 • Shift fork 3 (R) 3 • Shift cam 4 To main axle and drive axle. NOTE: • Apply the molybdenum disulfide oil on the shift fork grooves.
Page 228: Chassis
CHAS FRONT WHEEL AND REAR WHEEL EC500000 CHASSIS EC590000 FRONT WHEEL AND REAR WHEEL EC598000 FRONT WHEEL 1 Front wheel removal 2 Wheel bearing removal Extent of removal: 3 Brake disc removal Extent of removal Order Part name Q’ty Remarks FRONT WHEEL REMOVAL WARNING Preparation for removal...
Page 229 CHAS FRONT WHEEL AND REAR WHEEL EC598100 REAR WHEEL 1 Rear wheel removal 2 Wheel bearing removal Extent of 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 230 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 231 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 232 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. •...
Page 233 CHAS FRONT WHEEL AND REAR WHEEL 5. Install: • Wheel NOTE: • Install the brake disc 1 between the brake pads 2 correctly. • Make sure that the projections a in the trip meter gear unit fits over the stopper b on the front fork outer tube.
Page 234 CHAS FRONT WHEEL AND REAR WHEEL 8. Tighten: • Bolt (axle holder) 1 23 Nm (2.3 m · kg, 17 ft · lb) NOTE: Before tightening the bolt, fit the wheel axle to the axle holder by stroking the front fork sev- eral times with the front brake applied.
Page 235 CHAS FRONT WHEEL AND REAR WHEEL 11. Install: • Trip meter cable 1 Rear wheel 1. Install: • Bearing (right) 1 • Circlip 2 • Spacer 3 • Bearing (left) 4 • Oil seal 5 NOTE: • Apply the lithium soap base grease on the bearing and oil seal lip when installing.
Page 236 CHAS FRONT WHEEL AND REAR WHEEL 3. Install: • Rear wheel sprocket 1 • Bolt (rear wheel sprocket) 2 • Washer (rear wheel sprocket) 3 • Nut (rear wheel sprocket) 4 50 Nm (5.0 m · kg, 36 ft · lb) NOTE: Tighten the nuts in stage, using a crisscross pattern.
Page 237 CHAS FRONT WHEEL AND REAR WHEEL 8. Install: • Right drive chain puller 1 • 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...
Page 238: Front Brake And Rear Brake
CHAS FRONT BRAKE AND REAR BRAKE EC5A0000 FRONT BRAKE AND REAR BRAKE EC5A8000 FRONT BRAKE 1 Brake hose removal 2 Brake caliper removal Extent of removal: 3 Brake master cylinder removal Extent of removal Order Part name Q’ty Remarks FRONT BRAKE REMOVAL WARNING Preparation for removal Hold the machine by placing the...
Page 239 CHAS FRONT BRAKE AND REAR BRAKE EC5A8100 REAR BRAKE 1 Brake master cylinder removal 2 Brake hose removal Extent of removal: 3 Brake 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 240 CHAS FRONT BRAKE AND REAR BRAKE BRAKE CALIPER DISASSEMBLY È Front É Rear 1 Front brake caliper disassembly 2 Rear brake caliper disassembly Extent of removal: Extent of removal Order Part name Q’ty Remarks BRAKE CALIPER DISASSEM- Pad pin Brake pad Pad support Brake caliper piston Dust seal...
Page 241 CHAS FRONT BRAKE AND REAR BRAKE BRAKE MASTER CYLINDER DISASSEMBLY È Front É Rear 1 Front brake master cylinder disassembly 2 Rear brake master cylinder disassembly Extent of removal: Extent of removal Order Part name Q’ty Remarks BRAKE MASTER CYLINDER DISASSEMBLY Brake master cylinder cap Diaphragm...
Page 242 CHAS FRONT BRAKE AND REAR BRAKE EC5A3000 È REMOVAL POINTS Brake fluid 1. Remove: [Front] • Brake master cylinder cap 1 [Rear] • Brake master cylinder cap 1 • Protector NOTE: Do not remove the diaphragm. É È Front É Rear 2.
Page 243 CHAS FRONT BRAKE AND REAR BRAKE Brake caliper piston seal kit È 1. Remove: • Dust seal 1 • Piston seal 2 NOTE: Remove the piston seals and dust seals by pushing them with a finger. CAUTION: Never attempt to pry out piston seals and É...
Page 244 CHAS FRONT BRAKE AND REAR BRAKE Brake caliper È É 1. Inspect: • Brake caliper cylinder inner surface a Wear/score marks → Replace brake cali- per assembly. È Front É Rear 2. Inspect: • Brake caliper piston 1 Wear/score marks → Replace brake cali- per piston assembly.
Page 245 CHAS FRONT BRAKE AND REAR BRAKE 2. Install: È • 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 brake caliper correctly. É...
Page 246 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: Install the brake hose so that its pipe por- tion a directs as shown and lightly touches the projection b on the brake cali- per.
Page 247 CHAS FRONT BRAKE AND REAR BRAKE 2. Install: • Brake disc cover 1 • Bolt (brake disc cover) 2 7 Nm (0.7 m · kg, 5.1 ft · lb) 3. Install: • Brake caliper 1 • Rear wheel 2 Refer to “FRONT WHEEL AND REAR WHEEL”...
Page 248 CHAS FRONT BRAKE AND REAR BRAKE 3. Install: È É • Spring 1 To brake master cylinder piston 2. NOTE: Install the spring at the smaller dia. side. È Front É Rear 4. Install: È [Front] • Brake master cylinder kit 1 •...
Page 249 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...
Page 250 CHAS FRONT BRAKE AND REAR BRAKE 4. Install: • Pin 1 • 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.
Page 251 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: Install the brake hose so that it contacts the brake master cylinder projection a and that its bent portion b faces downward.
Page 252 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: After installing the brake hose holders, make sure the brake hose does not contact the spring (rear shock absorber).
Page 253 CHAS FRONT BRAKE AND REAR BRAKE 2. Air bleed: • Brake system Refer to “BRAKE SYSTEM AIR BLEED- ING” section in the CHAPTER 3. 3. Inspect: • Brake fluid level Fluid at lower level → Fill up. Refer to “BRAKE FLUID LEVEL INSPEC- TION”...
Page 254 CHAS FRONT FORK EC550000 FRONT FORK 1 Front fork removal Extent of 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 255 CHAS FRONT FORK EC558000 FRONT FORK DISASSEMBLY 1 Oil seal removal 2 Damper rod removal Extent of removal: Extent of removal Order Part name Q’ty Remarks FRONT FORK DISASSEMBLY Front fork cap bolt Refer to “REMOVAL POINTS”. Fork spring Drain the fork oil. Dust seal Stopper ring Refer to “REMOVAL POINTS”.
Page 256 CHAS FRONT FORK EC556000 HANDLING NOTE NOTE: The front fork requires careful attention. So it is recommended that the front fork be maintained at the dealers. CAUTION: To prevent an accidental explosion of air, following instructions should observed: • The front fork with a built-in piston rod has a very sophisticated internal construction and is particularly sensitive to foreign material.
Page 257 CHAS FRONT FORK EC553201 Inner tube 1. Remove: • Dust seal 1 • Stopper ring 2 Using slotted-head screwdriver. CAUTION: 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 •...
Page 258 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: 460 mm (18.1 in) <Limit>: 455 mm (17.9 in) EC554502...
Page 259 CHAS FRONT FORK Front fork cap bolt 1. Inspect: • Front fork 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.
Page 260 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 261 CHAS FRONT FORK 9. Install: • Slide metal 1 • Oil seal washer 2 To outer tube slot. NOTE: Press the slide metal into the outer tube with fork seal driver 3. 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 262: Front Fork
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 263 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 264 CHAS FRONT FORK 21. Measure: • Distance a Out of specification → Turn into the lock- nut. 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: •...
Page 265 CHAS FRONT FORK 26. Tighten: • Front fork 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. •...
Page 266 CHAS FRONT FORK 4. Tighten: • Pinch bolt (upper bracket) 1 23 Nm (2.3 m · kg, 17 ft · lb) • Pinch bolt (lower bracket) 2 20 Nm (2.0 m · kg, 14 ft · lb) CAUTION: Tighten the lower bracket to specified torque.
Page 267 CHAS HANDLEBAR EC5B0000 HANDLEBAR 1 Handlebar removal Extent of removal: Extent of removal Order Part name Q’ty Remarks HANDLEBAR REMOVAL Preparation for removal Headlight Hot starter cable Disconnect at the lever side. Hot starter lever holder Clutch cable Disconnect at the lever side. Clutch lever holder Disconnect the clutch switch lead.
Page 268: Handlebar
CHAS HANDLEBAR EC5B3000 REMOVAL POINTS Brake master cylinder 1. Remove: • Brake master cylinder bracket 1 • Brake master cylinder 2 CAUTION: • Do not let the brake master cylinder hang on the brake hose. • Keep the brake master cylinder cap side horizontal to prevent air from coming in.
Page 269 CHAS HANDLEBAR EC5B5000 ASSEMBLY AND INSTALLATION Handlebar 1. Install: • Handlebar 1 • Handlebar upper holder 2 • Bolt (handlebar upper holder) 3 28 Nm (2.8 m · kg, 20 ft · lb) NOTE: • The handlebar upper holder should be installed with the punched mark a forward.
Page 270 CHAS HANDLEBAR 4. Install: • Grip cap cover 1 • Throttle grip 2 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 271 CHAS HANDLEBAR 8. Install: • Start switch 1 • Brake master cylinder 2 • Brake master cylinder bracket 3 • Bolt (brake master cylinder bracket) 4 9 Nm (0.9 m · kg, 6.5 ft · lb) • Clamp 5 NOTE: •...
Page 272 CHAS HANDLEBAR 11. Install: • Clutch cable 1 • Hot starter cable 2 NOTE: Apply the lithium soap base grease on the clutch cable end and hot starter cable end. 12. Adjust: • Clutch lever free play Refer to “CLUTCH ADJUSTMENT” sec- tion in the CHAPTER 3.
Page 273: Steering
CHAS STEERING EC560000 STEERING 1 Lower bracket removal 2 Bearing removal Extent of 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 274 CHAS STEERING Extent of removal Order Part name Q’ty Remarks Ball race cover Upper bearing Lower bearing Refer to “REMOVAL POINTS”. Ball race www.PlanDeGraissage.org 5 - 47...
Page 275 CHAS STEERING EC563000 REMOVAL POINTS Steering ring nut 1. Remove: • Steering ring nut 1 Use the steering nut wrench 2. Steering nut wrench: YU-33975/90890-01403 WARNING Support the steering stem so that it may not fall down. Lower bearing 1. Remove: •...
Page 276 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 277 CHAS STEERING 4. Install: • Washer 1 • Steering ring nut 2 7 Nm (0.7 m · kg, 5.1 ft · lb) Tighten the steering ring nut using the steering nut wrench 3. Refer to “STEERING HEAD INSPEC- TION AND ADJUSTMENT” section in the CHAPTER 3.
Page 278 CHAS STEERING 8. Install: • Washer 1 • Steering stem nut 2 145 Nm (14.5 m · kg, 105 ft · lb) 9. Install: • Steering stem cap 1 10. After tightening the nut, check the steering for smooth movement. If not, adjust the steering by loosening the steering ring nut little by little.
Page 279 CHAS STEERING 13. Install: • Trip meter 1 • Bolt (trip meter) 2 7 Nm (0.7 m · kg, 5.1 ft · lb) NOTE: Install the trip meter over the coupler bracket www.PlanDeGraissage.org 5 - 52...
Page 280: Swingarm
CHAS SWINGARM EC570000 SWINGARM 1 Swingarm removal Extent of 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 281 CHAS SWINGARM EC578000 SWINGARM DISASSEMBLY 1 Swingarm disassembly 2 Connecting rod removal and disassembly Extent of removal: 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 Bushing Oil seal...
Page 282 CHAS SWINGARM EC573000 REMOVAL POINTS EC573200 Bearing 1. Remove: • Bearing 1 NOTE: Remove the bearing by pressing its outer race. INSPECTION Wash the bearings, bushings, collars, and cov- ers in a solvent. Swingarm 1. Inspect: • Bearing 1 • Bushing 2 Free play exists/unsmooth revolution/rust →...
Page 283 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. •...
Page 284 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 285 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 • Washer 3 • Nut (connecting rod) 4 80 Nm (8.0 m ·...
Page 286 CHAS SWINGARM 8. Install: • Bolt (connecting rod) 1 • 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 •...
Page 287 CHAS SWINGARM 13. Install: • Bolt (lower chain tensioner) 1 • Washer 2 • Collar 3 • Lower chain tensioner 4 • Nut (lower chain tensioner) 5 20 Nm (2.0 m · kg, 14 ft · lb) 14. Install: • Drive chain support 1 •...
Page 288: Rear Shock Absorber
CHAS REAR SHOCK ABSORBER EC580000 REAR SHOCK ABSORBER 1 Rear shock absorber removal 2 Rear shock absorber disassembly Extent of removal: 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 289 CHAS REAR SHOCK ABSORBER Extent of removal Order Part name Q’ty Remarks Locking tie Taillight coupler Starting circuit cut-off relay coupler Plastic band Clamp (air filter joint) Only loosening. Rear frame Bolt Hold the swingarm. (rear shock absorber-relay arm) Bolt (rear shock absorber-frame) Rear shock absorber Locknut Only loosening.
Page 290 1. Wear eye protection to prevent eye damage from escaping gas and/or metal chips. WARNING To dispose of a damaged or worn-out rear shock absorber, take the unit to your Yamaha dealer for this disposal procedure. www.PlanDeGraissage.org 5 - 63...
Page 291 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 292 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: 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 293 CHAS REAR SHOCK ABSORBER 2. Tighten: • Adjuster 1 3. Adjust: • Spring length (installed) a Spring length (installed) a: Extent of Standard length adjustment 245 mm (9.65 in) 240.5 ~ 258.5 mm * 246.5 mm (9.70 in) (9.47 ~ 10.18 in) * For EUROPE NOTE: The length of the spring (installed) changes...
Page 294 CHAS REAR SHOCK ABSORBER 2. Install: • Bushing 1 • Collar 2 • Dust seal 3 NOTE: • Apply the molybdenum disulfide grease on the bearing. • Apply the lithium soap base grease on the bushing, collars and dust seals. •...
Page 295 CHAS REAR SHOCK ABSORBER 8. Install: • Plastic band 1 • Starting circuit cut-off relay coupler 2 • Taillight coupler 3 • Locking tie 4 www.PlanDeGraissage.org 5 - 68...
Page 296: Electrical Components And Wiring Diagram
– ELEC ELECTRICAL COMPONENTS AND WIRING DIAGRAM EC600000 ELECTRICAL EC610000 ELECTRICAL COMPONENTS AND WIRING DIAGRAM EC611000 ELECTRICAL COMPONENTS 1 Headlight A Neutral switch COLOR CODE 2 Engine stop switch B Starter motor B/W....Black/White B.......Black L/B ....Blue/Black 3 Clutch switch C AC magneto Br .....Brown L/R ....
Page 297: Map-Controlled Cdi Unit
– ELEC MAP-CONTROLLED CDI UNIT MAP-CONTROLLED CDI UNIT A map-controlled, CDI ignition system is used in the WR250F. 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 298: 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. No good Replace fuse and *1 Check fuse.
Page 299 – ELEC IGNITION SYSTEM SPARK GAP TEST È 1. Disconnect the ignition coil from spark plug. 2. Remove the ignition coil cap. 3. Connect the dynamic spark tester 1 (igni- tion checker 2) as shown. • Ignition coil 3 • Spark plug 4 È...
Page 300 – ELEC IGNITION SYSTEM 2. Inspect: • Rubber part a Tears/damage → Replace. MAIN SWITCH INSPECTION 1. Inspect: • Main switch conduct Tester (+) lead → Red lead 1 Tester (–) lead → Brown lead 2 Tester selector position Ω × 1 Continuous while the main switch is moved to “OFF”...
Page 301 – 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 302 – ELEC IGNITION SYSTEM AC MAGNETO INSPECTION 1. Inspect: • Pickup coil resistance Out of specification → Replace. Tester (+) lead → Red lead 1 Tester (–) lead → White lead 2 Pickup coil Tester selector resistance position 248 ~ 372 Ω at Ω...
Page 303: Electric Starting System
– ELEC ELECTRIC STARTING SYSTEM ELECTRIC STARTING SYSTEM STARTING CIRCUIT CUT-OFF SYSTEM OPERATION If the main switch is set to “ON”, the starter motor can only operate if at least one of the fol- lowing conditions is met: • The transmission is in neutral (the neutral switch is closed).
Page 304 – ELEC ELECTRIC STARTING SYSTEM INSPECTION STEPS If the starter motor will not operate, use the following inspection steps. No good Replace fuse and *1 Check fuse. check wire harness. No good *2 Check battery. Recharge or replace. No good Check each coupler and Repair or replace.
Page 305 – ELEC ELECTRIC STARTING SYSTEM EC624000 COUPLERS AND LEADS CONNECTION INSPECTION 1. Check: • Couplers and leads connection Rust/dust/looseness/short-circuit → Repair or replace. STARTER MOTOR OPERATION 1. Connect the positive battery terminal 1 and starter motor lead 2 with a jumper lead 3.
Page 306 – ELEC ELECTRIC STARTING SYSTEM STARTER RELAY INSPECTION 1. Remove: • Starter relay 2. Inspect: • Starter relay conduct Use 12 V battery. Battery (+) lead → Starter relay terminal 1 Battery (–) lead → Starter relay terminal 2 Tester (+) lead → Starter relay terminal 3 Tester (–) lead →...
Page 307 – ELEC ELECTRIC STARTING SYSTEM DIODE INSPECTION 1. Remove the diode from wire harness. 2. Inspect: • Diode continuity Use pocket tester (tester selection position Ω × 1) Tester (+) → Blue/Red terminal 1 Continuous Tester (–) → Sky blue terminal 2 Tester (+) →...
Page 308 – ELEC ELECTRIC STARTING SYSTEM STARTER MOTOR 1 Starter motor disassembly Extent of removal: Extent of removal Order Part name Q’ty Remarks STARTER MOTOR REMOVAL Exhaust pipe Refer “EXHAUST PIPE SILENCER” section in the CHAPTER 4. Preparation for removal Starter motor STARTER MOTOR DISASSEM- Starter motor front cover Washer (starter motor front cover)
Page 309 – ELEC ELECTRIC STARTING SYSTEM INSPECTION AND REPAIR 1. Check: • Commutator Dirt → Clean with 600 grit sandpaper. 2. Measure: • Commutator diameter a Out of specification → Replace the starter motor. Min. commutator diameter: 16.6 mm (0.65 in) 3.
Page 310 – ELEC ELECTRIC STARTING SYSTEM 5. Measure: • Brush length a Out of specification → Replace the brushes as a set. Min. brush length: 3.5 mm (0.14 in) 6. Measure: • Brush spring force Out of specification → Replace the brush springs as a set.
Page 311 – ELEC ELECTRIC STARTING SYSTEM 4. Install: • Gasket 1 • Circlip • Plain washer 2 • Washer (starter motor front cover) 3 • Starter motor front cover 4 NOTE: • For installation, align the projections on the washer with the slots in the front cover. •...
Page 312: Charging System
– ELEC CHARGING SYSTEM EC680000 CHARGING SYSTEM EC681001 INSPECTION STEPS If the battery is not charged, use the following inspection steps. No good Replace fuse and *1 Check fuse. check wire harness. No good *2 Check battery. Recharge or replace. No good Check each coupler and Repair or replace.
Page 313 – ELEC CHARGING SYSTEM EC624000 COUPLERS AND LEADS CONNECTION INSPECTION 1. Check: • Couplers and leads connection Rust/dust/looseness/short-circuit → Repair or replace. CHARGING VOLTAGE INSPECTION 1. Start the engine. 2. Inspect: • Charging voltage Out of specification → If no failure is found in checking the source coil resis- tance, replace the rectifier/regulator.
Page 314: Throttle Position Sensor System
– ELEC THROTTLE POSITION SENSOR SYSTEM THROTTLE POSITION SENSOR SYSTEM INSPECTION STEPS If the throttle position sensor will not operate, use the following inspection steps. No good Check entire ignition Repair or replace. system for connection. Check throttle position Throttle posi- No good Replace.
Page 315 – ELEC THROTTLE POSITION SENSOR SYSTEM HANDLING NOTE CAUTION: Do not loosen the screws (throttle position sensor) 1 except when changing the throt- tle position sensor due to failure because it will cause a drop in engine performance. EC624000 COUPLERS AND LEADS CONNECTION INSPECTION 1.
Page 316 – ELEC THROTTLE POSITION SENSOR SYSTEM 3. Inspect: • Throttle position sensor coil variable resistance Check that the resistance in increased as the throttle grip is moved from the full close position to the full open position. Out of specification → Replace. Tester (+) lead →...
Page 317 – ELEC THROTTLE POSITION SENSOR SYSTEM 4. Adjust: • Engine idling speed Refer to “ENGINE IDLING SPEED ADJUSTMENT” section in the CHAPTER 5. Insert the thin electric conductors 2 (lead) into the throttle position sensor coupler 1, as shown, and connect the tester to them. Tester (+) lead →...
Page 318 – ELEC THROTTLE POSITION SENSOR SYSTEM 8. Tighten: • Screw (throttle position sensor) 1 9. Stop the engine. THROTTLE POSITION SENSOR INPUT VOLTAGE INSPECTION 1. Disconnect the throttle position sensor cou- pler. 2. Start the engine. 3. Inspect: • Throttle position sensor input voltage Out of specification →...
Page 319: Lighting System
– ELEC LIGHTING SYSTEM LIGHTING SYSTEM INSPECTION STEPS Refer to the following flow chart when inspecting the ignition system for possible problems. Check the bulb and bulb No good Replace the bulb and/ socket. or bulb socket. No good Check the light switch. Replace.
Page 320 – ELEC LIGHTING SYSTEM LIGHT SWITCH INSPECTION 1. Inspect: • Light switch conduct Tester (+) lead → Yellow lead 1 Tester (–) lead → Blue lead 2 Tester selector position Ω × 1 → Replace. No continuous while being Continuous while being OFF → Replace. AC MAGNETO INSPECTION 1.
Page 321: 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. •...
Page 322 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 carburetor parts may prevent the carburetor from...
Page 323 T U N SETTING Effects of the setting parts on the throttle valve opening È É È Closed É Fully open 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 324 T U N SETTING 1 Jet needle 2 Pilot air jet 3 Needle jet 4 Main jet 5 Pilot jet 6 Pilot screw Main jet adjustment The richness of the air-fuel mixture at full throt- tle can be set by changing the main jet 1. #185 Standard main jet * #172...
Page 325 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 326 T U N SETTING Effects of adjusting the pilot jet (reference) È É –5% È Idle É Fully open Jet needle groove position adjustment Adjusting the jet needle 1 position affects the acceleration when the throttle is 1/8 to 3/4 open.
Page 327 T U N SETTING Jet needle adjustment The jet needle is adjusted by changing it. OBDVS Standard jet needle * OBELP * Except for USA The tapered sections of all jet needles have the same starting positions, but the needles are available with different straight-portion diameters.
Page 328 T U N SETTING Leak jet adjustment (accelerator pump adjustment) The leak jet 1 is a setting part that adjusts the flow of fuel discharged by the accelerator pump. Since the accelerator pump operates only when throttle is open, the leak jet is used to adjust a fuel mixture ratio for quick throttle opening and is therefore different from other setting parts that adjust a fuel mixture for each...
Page 329 T U N SETTING EC71Q000 Carburetor setting parts Part name Size Part number Main jet Rich #198 4MX-14943-97 #195 4MX-14943-46 #192 4MX-14943-96 #190 4MX-14943-45 #188 4MX-14943-95 (STD) #185 4MX-14943-44 #182 4MX-14943-94 #180 4MX-14943-43 #178 4MX-14943-93 #175 4MX-14943-42 * (STD) #172 4MX-14943-92 #170 4MX-14943-41...
Page 330 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 331: Chassis
T U N SETTING EC720000 CHASSIS Selection of the secondary reduction ratio (Sprocket) Secondary Number of rear wheel sprocket teeth reduction Number of drive sprocket teeth ratio Standard secondary 52/13 (4.000) reduction ratio <Requirement for selection of secondary gear reduction ratio> •...
Page 332 T U N SETTING EC72N000 Drive and rear wheel sprockets setting parts Part name Size Part number Drive sprocket 1 (STD) 9383B-13218 Rear wheel 5GS-25448-50 sprocket 2 * 48T 5NY-25448-00 * 49T 5NY-25449-00 5GS-25450-50 * 50T 5NY-25450-00 * 51T 5NY-25451-00 5GS-25452-50 (STD) * 52T...
Page 333 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 •...
Page 334 T U N SETTING È Air spring characteristics in relation to oil level change É Load Ê Stroke 1 Max. oil level 2 Standard oil level 3 Min. oil level EC727020 Spring preload adjustment The spring preload is adjusted by installing the adjustment washer 1 between the fork spring 2 and damper rod 3.
Page 335 T U N SETTING EC72A001 Setting of spring after replacement As the front fork setting can be easily affected by rear suspension, take care so that the machine front and rear are balanced (in posi- tion, etc.) when setting the front fork. 1.
Page 336 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) 0.380 4SS-23141-10...
Page 337 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 •...
Page 338 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 339 T U N SETTING CAUTION: When using a rear shock absorber other than currently installed, use the one whose overall length a does not exceed the stan- dard as it may result in faulty performance. Never use one whose overall length is greater than standard.
Page 340 T U N SETTING EC72Q000 Rear shock absorber setting parts • Rear shock spring 1 [Equal pitch spring] I.D. SPRING SPRING SPRING PART TYPE COLOR/ FREE RATE NUMBER POINT LENGTH 5UN-22212-00 Brown/1 SOFT 5UN-22212-10 Green/1 * STD 5UN-22212-20 Red/1 5UN-22212-30 Black/1 5UN-22212-80 Orange/1 ** STD 5UN-22212-40...
Page 341 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. •...
Page 342 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. •...
Page 343 YAMAHA MOTOR CO., LTD. PRINTED ON RECYCLED PAPER PRINTED IN JAPAN 2002.11-1.8×1 CR 2500 SHINGAI IWATA SHIZUOKA JAPAN www.PlanDeGraissage.org...

Yamaha WR250FR 2002 Owner's Service Manual

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