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Yamaha Raptor 90 YFM90RA 2011 Service Manual
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Yamaha Raptor 90 YFM90RA 2011 Service Manual

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2011
SERVICE MANUAL
YFM90RA
LIT-11616-24-16
43D-F8197-12

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Summary of Contents for Yamaha Raptor 90 YFM90RA 2011

  • Page 1 2011 SERVICE MANUAL YFM90RA LIT-11616-24-16 43D-F8197-12...
  • Page 2 EBS00001 YFM90RA SERVICE MANUAL ©2010 by Yamaha Motor Corporation, U.S.A. First edition, July 2010 All rights reserved. Any reproduction or unauthorized use without the written permission of Yamaha Motor Corporation, U.S.A. is expressly prohibited. Printed in U.S.A. LIT-11616-24-16...
  • Page 3 EBS00002 IMPORTANT This manual was produced by the Yamaha Motor Company primarily for use by Yamaha dealers and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one man- ual, so it is assumed that anyone who uses this book to perform maintenance and repairs on Yamaha machine has a basic understanding of the mechanical ideas and the procedures of machine repair.
  • Page 4 EBS00004 HOW TO USE THIS MANUAL MANUAL ORGANIZATION This manual consists of chapters for the main categories of subjects. (See “symbols”) 1st title : This is the title of the chapter with its symbol in the upper right corner of each page. 2nd title : This title indicates the section of the chapter and only appears on the first page of each section.
  • Page 5 EBS00005 SYMBOLS The following symbols are not relevant to SPEC every machine. INFO Symbols indicate the subject of each chapter. General information Specifications Periodic checks and adjustments Engine Carburetor Chassis Electrical CHAS CARB Troubleshooting TRBL ELEC – SHTG Symbols indicate the following. Serviceable with engine mounted Filling fluid Lubricant...
  • Page 7 TABLE OF CONTENTS EBS00007 GENERAL INFORMATION INFO SPECIFICATIONS SPEC PERIODIC CHECKS AND ADJUSTMENTS ENGINE CARBURETOR CARB CHASSIS CHAS – ELECTRICAL ELEC TROUBLESHOOTING TRBL SHTG...

  • Page 8: Table Of Contents

    CONTENTS CHAPTER 1 GENERAL INFORMATION MACHINE IDENTIFICATION................1-1 VEHICLE IDENTIFICATION NUMBER .............1-1 MODEL LABEL..................1-1 IMPORTANT INFORMATION ................. 1-2 PREPARATION FOR REMOVAL AND DISASSEMBLY......1-2 REPLACEMENT PARTS................1-2 GASKETS, OIL SEALS AND O-RINGS ............ 1-2 LOCK WASHERS/PLATES AND COTTER PINS ........1-3 BEARINGS AND OIL SEALS ..............
  • Page 9 OIL FLOW DIAGRAMS ................. 2-21 CABLE ROUTING ..................2-22 CHAPTER 3 PERIODIC CHECKS AND ADJUSTMENTS INTRODUCTION....................3-1 PERIODIC MAINTENANCE/LUBRICATION ..........3-1 SEAT, FENDERS AND FUEL TANK .............. 3-3 SEAT AND FRONT PANEL ..............3-3 FRONT FENDER ..................3-4 REAR FENDER AND FOOTREST BOARDS ...........3-5 FUEL TANK....................
  • Page 10 ELECTRICAL SYSTEM................. 3-37 CHECKING AND CHARGING THE BATTERY........3-37 CHECKING THE FUSES.................3-44 CHAPTER 4 ENGINE ENGINE ......................4-1 EXHAUST PIPE/MUFFLER, BREATHER HOSE AND LEADS ....4-1 ENGINE MOUNTING BOLTS ..............4-2 REMOVING THE ENGINE ................4-3 INSTALLING THE ENGINE............... 4-3 CYLINDER HEAD....................4-4 REMOVING THE CYLINDER HEAD............4-6 CHECKING THE CAMSHAFT SPROCKET..........4-7 CHECKING THE CYL.
  • Page 11 BELT DRIVE ....................4-31 CRANKCASE COVER................4-31 KICKSTARTER..................4-32 INSTALLING THE KICKSTARTER............4-33 V-BELT, CLUTCH, PRIMARY AND SECONDARY SHEAVE....4-34 DISASSEMBLING THE SECONDARY SHEAVE........4-35 REMOVING THE PRIMARY SHEAVE............4-36 REMOVING THE SECONDARY SHEAVE AND V-BELT......4-36 DISASSEMBLING THE SECONDARY SHEAVE........4-37 CHECKING THE CLUTCH SHOE............4-37 CHECKING THE V-BELT................4-38 CHECKING THE PRIMARY SHEAVE.............4-38 CHECKING THE PRIMARY SHEAVE WEIGHTS........
  • Page 12 CHAPTER 5 CARBURETOR CARBURETOR....................5-1 DISASSEMBLING THE CARBURETOR........... 5-4 CHECKING THE CARBURETOR ............. 5-4 ASSEMBLING THE CARBURETOR............5-6 INSTALLING THE CARBURETOR ............5-7 MEASURING AND ADJUSTING THE FUEL LEVEL ........5-8 CHAPTER 6 CHASSIS FRONT AND REAR WHEELS ................ 6-1 FRONT WHEELS ..................6-1 REAR WHEELS ..................6-2 CHECKING THE WHEELS ...............
  • Page 13 REAR BRAKES ....................6-16 REAR BRAKE PADS................6-16 REPLACING THE REAR BRAKE PADS..........6-17 REAR BRAKE MASTER CYLINDER............6-19 CHECKING THE MASTER CYLINDER........... 6-20 ASSEMBLING THE REAR BRAKE MASTER CYLINDER......6-20 INSTALLING THE REAR BRAKE MASTER CYLINDER......6-21 REAR BRAKE CALIPER................6-23 REMOVING THE PARKING BRAKE CABLE..........6-25 CHECKING THE REAR BRAKE CALIPER..........6-25 INSTALLING THE REAR BRAKE CALIPER..........6-26 STEERING SYSTEM ..................6-28...
  • Page 14 REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN....6-43 REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN.....6-43 REMOVING THE REAR SHOCK ABSORBER........6-45 CHECKING THE REAR SHOCK ABSORBER........6-45 REMOVING THE SWINGARM..............6-45 CHECKING THE SWINGARM..............6-46 CHECKING THE DRIVE CHAIN..............6-47 INSTALLING THE DRIVE SPROCKET...........6-48 INSTALLING THE DRIVE CHAIN............6-48 CHAPTER 7 ELECTRICAL...
  • Page 15 CHAPTER 8 TROUBLESHOOTING STARTING FAILURE/HARD STARTING ............8-1 FUEL SYSTEM..................8-1 ELECTRICAL SYSTEM................8-1 COMPRESSION SYSTEM................ 8-2 POOR IDLE SPEED PERFORMANCE ............8-2 POOR IDLE SPEED PERFORMANCE.............8-2 POOR MEDIUM AND HIGH-SPEED PERFORMANCE........8-2 POOR MEDIUM AND HIGH-SPEED PERFORMANCE ......8-2 FAULTY CLUTCH ...................8-3 ENGINE OPERATES BUT VEHICLE WILL NOT MOVE......8-3 POOR STARTING PERFORMANCE............

  • Page 16: General Information

    MACHINE IDENTIFICATION INFO EBS00009 GENERAL INFORMATION MACHINE IDENTIFICATION EBS00010 VEHICLE IDENTIFICATION NUMBER The vehicle identification number is stamped into the left side of the frame. EBS00011 MODEL LABEL The model label is affixed to the frame. This information will be needed to order spare parts.

  • Page 17: Important Information

    5. Keep all parts away from any source of fire. EBS00014 REPLACEMENT PARTS 1. Use only genuine Yamaha parts for all replacements. Use oil and grease recom- mended by Yamaha for all lubrication jobs. Other brands may be similar in function and appearance, but inferior in quality.

  • Page 18: Lock Washers/Plates And Cotter Pins

    IMPORTANT INFORMATION INFO EBS00016 LOCK WASHERS/PLATES AND COTTER PINS After removal, replace all lock washers/plates and cotter pins. After the bolt or nut has been tightened to specification, bend the lock tabs along a flat of the bolt or nut. EBS00017 BEARINGS AND OIL SEALS Install bearings and oil seals so that the manu-...

  • Page 19: Checking The Connections

    IMPORTANT INFORMATION INFO EBS00019 CHECKING THE CONNECTIONS Check the leads, couplers, and connectors for stains, rust, moisture, etc. 1. Disconnect: • lead • coupler • connector 2. Check: • lead • coupler • connector Moisture → Dry with an air blower. Rust/stains →...

  • Page 20: Special Tools

    SPECIAL TOOLS INFO EBS00021 SPECIAL TOOLS The following special tools are necessary for complete and accurate tune-up and assembly. Use only the appropriate special tools; this will help prevent damage caused by the use of inappropriate tools or improvised techniques. Special tools may differ by shape and part number from country to country.
  • Page 21 This tool is used to remove the flywheel magneto. Thickness gauge 90890-03079 YM-34483 This tool is used to measure the valve cleanance. Yamaha bond No. 1215 Bond ® Sealant (Quick Gasket 90890-85505 Sealant ACC-11001-05-01 This sealant (bond) is used on crankcase mating surfaces, etc.
  • Page 22 SPECIAL TOOLS INFO Tool No. Tool name/Function Illustration Ignition checker 90890-06754 This instrument is necessary for checking the ignition system components. Dynamic spark tester YM-34487 This instrument is necessary for checking the ignition system components. Oil seal guide 90890-01384 YM-33299 This tool is used for protecting the oil seal lip when installing the secondary sliding sheave.

  • Page 23: Specifications

    SPEC GENERAL SPECIFICATIONS EBS01001 SPECIFICATIONS GENERAL SPECIFICATIONS Item Standard Model code 43D7 Dimensions Overall length 1,490 mm (58.7 in) Overall width 885 mm (34.8 in) Overall height 910 mm (35.8 in) Seat height 654 mm (25.7 in) Wheelbase 1,010 mm (39.8 in) Minimum ground clearance 100 mm (3.9 in) Minimum turning radius...
  • Page 24 SPEC GENERAL SPECIFICATIONS Item Standard Fuel Type Unleaded gasoline only Fuel tank capacity 4.8 L (1.06 lmp gal, 1.27 US gal) Fuel reserve amount 1.0 L (0.22 Imp gal, 0.26 US gal) Carburetor Type/quantity SVR 22-1G x 1 Manufacturer Spark plug Type/manufacturer NGK/CR7HSA Spark plug gap...
  • Page 25 SPEC GENERAL SPECIFICATIONS Item Standard Brake Front brake type Drum brake operation Right hand operation Rear brake type Single disc brake operation Left hand operation Suspension Front suspension Double wishbone / Independent Rear suspension Swingarm Shock absorber Front shock absorber Coil spring/oil damper Rear shock absorber Coil spring/oil damper...

  • Page 26: Engine Specifications

    SPEC ENGINE SPECIFICATIONS EBS01002 ENGINE SPECIFICATIONS Item Standard Limit Cylinder head Warp limit 7.00 ~ 7.40 cm 0.05 mm (0.43 ~ 0.45 cu.in) (0.002 in) Cylinder Bore size 47.000 ~ 47.010 mm 47.10 mm (1.8504 ~ 1.8508 in) (1.8543 in) Taper limit ---- 0.05 mm...
  • Page 27 SPEC ENGINE SPECIFICATIONS Item Standard Limit Rocker arm/rocker arm shaft Rocker arm inside diameter 10.000 ~ 10.015 mm 10.100 mm (0.3937 ~ 0.3943 in) (0.3976 in) Rocker arm shaft outside diameter 9.972 ~ 9.987 mm 9.910 mm (0.3902 in) (0.3926 ~ 0.3932 in) Rocker-arm-to-rocker-arm-shaft clearance 0.013 ~ 0.043 mm ----...
  • Page 28 SPEC ENGINE SPECIFICATIONS Item Standard Limit Stem-to-guide clearance 0.010 ~ 0.037 mm 0.08 mm (0.0004 ~ 0.0015 in) (0.0031 in) 0.025 ~ 0.052 mm 0.10 mm (0.0010 ~ 0.0020 in) (0.0039 in) Stem runout limit ---- 0.02 mm (0.0008 in) Valve seat width 0.8 ~ 1.1 mm 1.6 mm...
  • Page 29 SPEC ENGINE SPECIFICATIONS Item Standard Limit Compressed pressure ---- 73.87 ~ 90.06 N at 25.45 mm installed) 7.52 ~ 9.18 kg, 16.59 ~ 20.24 lb at 1.00 in) ---- 73.87 ~ 90.06 N at 25.45 mm 7.52 ~ 9.18 kg, 16.59 ~ 20.24 lb at 1.00 in) °/1.2 mm Tilt limit...

  • Page 30: Specifications

    SPEC ENGINE SPECIFICATIONS Item Standard Limit Piston rings Top ring Type ---- Barrel ---- Dimensions (B × T) 1.0 × 2.1 mm (0.0394 × 0.0827 in) 0.45 mm End gap (installed) 0.10 ~ 0.25 mm (0.0177in) (0.0039~0.0098in) 0.09 mm Side clearance (installed) 0.015 ~0.055 mm (0.0035in) (0.0006~0.0022in)
  • Page 31 SPEC ENGINE SPECIFICATIONS Item Standard Limit Clutch Clutch type Automatic centrifugal ---- Clutch shoe thickness 4.0 mm 0 mm (0.1575 in) (0.078 in) 30.5 mm Clutch shoe spring free length ---- Clutch housing inside diameter 107.0 ~107.2 mm 107.5 mm (4.21 ~4.22 in) (4.23in) 87.9 mm (3.46 in)

  • Page 32: Engine

    SPEC ENGINE SPECIFICATIONS Item Standard Limit Oil pump Oil pump type Trochoid ---- Inner-rotor-to-outer-rotor-tip clearance 0.04 ~ 0.12mm 0.15 mm (0.0016 ~ 0.0047 in) (0.006 in) Outer-rotor-to-oil-pump-housing clearance 0.14 ~ 0.21 mm 0.28 mm (0.0055 ~ 0.0083 in) (0.0110 in) Oil-pump-housing-to-inner-rotor-and-outer- 0.06 ~ 0.11 mm 0.20 mm...

  • Page 33: Chassis Specifications

    SPEC CHASSIS SPECIFICATIONS EBS01003 CHASSIS SPECIFICATIONS Item Standard Limit Front suspension Shock absorber travel 35 mm (1.38 in) ---- Optional spring ---- Rear suspension Shock absorber travel 40 mm (1.57 in) ---- Optional spring ---- Front wheel Type Panel wheel ---- Rim size 8 ×...

  • Page 34: Chassis

    SPEC CHASSIS SPECIFICATIONS Item Standard Limit Rear disc brake Type Single ---- Disc outside diameter × thickness 190.0 × 3.5 mm (7.48 × 0.14 in) 3.0 mm (0.12 in) Brake disk maximum deflection 0.15 mm (0.006 in) Pad thickness inner 3.7 mm (0.15 in) 1.0 mm (0.04 in)

  • Page 35: Electrical Specifications

    SPEC ELECTRICAL SPECIFICATIONS EBS01004 ELECTRICAL SPECIFICATIONS Item Standard Limit Voltage 12 V ---- Ignition system Ignition timing (B.T.D.C.) 13.0 °/1,700 r/min ---- Advanced timing (B.T.D.C.) 29°/4,000 r/min ---- Advancer type Electrical (digital) ---- C.D.I. Magneto model/manufacturer C1120-A26-6000/SHIHLIN ---- Ω Pickup coil resistance/color 94 ~ 140 at 20 °C (68 °F)/ ----...
  • Page 36 SPEC ELECTRICAL SPECIFICATIONS Item Standard Limit Electric starter system Type Constant mesh ---- Starter motor Model/manufacturer C1200-A26-6000/SY ---- Output 0.35 kW ---- Ω Armature coil resistance 0.014 ~ 0.019 at 20 °C (68 ° ---- Brush overall length 7.0 mm (0.28 in) 3.5 mm (0.14 in) Spring force...

  • Page 37: Tightening Torques

    SPEC TIGHTENING TORQUES EBS01005 TIGHTENING TORQUES ENGINE TIGHTENING TORQUES Tightening torque Thread Part to be tightened Part name Q’ty Remarks size Nm m · kg ft · lb Cover head cylinder Bolt Cap camshaft Spark plug — Cylinder head (Carb. joint) Stud bolt Cylinder head (exhaust pipe) Stud bolt...

  • Page 38: Chassis Tightening Torques

    SPEC TIGHTENING TORQUES EBS01006 CHASSIS TIGHTENING TORQUES Tightening torque Part to be tightened Thread size Remarks Nm m · kg ft · lb Engine lower stay and engine 25.3 Engine and frame 25.3 Engine lower stay and frame 25.3 Swingarm pivot shaft and frame 54.2 Rear shock absorber and frame 25.3...
  • Page 39 SPEC TIGHTENING TORQUES ® 1. Before tightening the nuts, apply locking agent (LOCTITE ) to rear axle threads. 2. Tighten the inside nut to 60 Nm (6.0 m · kg, 43.4 ft · lb). 3. Tighten the outside nut to 170 Nm (17.0 m · kg, 123 ft · lb) while holding the inside nut. 2 - 17...

  • Page 40: How To Use The Conversion Table

    HOW TO USE THE CONVERSION TABLE/ SPEC GENERAL TIGHTENING TORQUE SPECIFICATIONS EBS00022 EBS00023 HOW TO USE THE CONVERSION GENERAL TIGHTENING TORQUE TABLE SPECIFICATIONS All specification data in this manual are listed This chart specifies tightening torques for stan- in SI and METRIC UNITS. dard fasteners with a standard ISO thread Use this table to convert METRIC unit data to pitch.

  • Page 41: Lubrication Points And Lubricant Types

    SPEC LUBRICATION POINTS AND LUBRICANT TYPES EBS00024 LUBRICATION POINTS AND LUBRICANT TYPES ENGINE Lubrication Point Lubricant Oil seal lips O-ring (Except V-belt drive unit) Cylinder head tightening nut mounting surface Cylinder head stud bolt thread Cylinder head gasket dowel pin Crankshaft pin outside surface Connecting rod Piston outside and ring groove...
  • Page 42 SPEC LUBRICATION POINTS AND LUBRICANT TYPES Lubrication Point Lubricant Primary sheave inside, Collar, Solid bush, Secondary fixed inner surface BEL-RAY asembly lube Secondary sheave torque cam ditch BEL-RAY asembly lube Gasket (Cylinder head cover) Sealant Stopper guide (Cylinder head cover) Sealant Crankcase mating surfaces Sealant...

  • Page 43: Oil Flow Diagrams

    SPEC OIL FLOW DIAGRAMS EBS00026 OIL FLOW DIAGRAMS Camshaft Crankshaft Oil pump Oil filter 2 - 21...

  • Page 44: Cable Routing

    SPEC CABLE ROUTING EBS00028 CABLE ROUTING Front brake cables Air filter case check hose Fuel drain hose Rear brake hose Fuel hose Parking brake cable Throttle valve hose Wire harness Throttle cable Fuel overflow hose Rear brake switch lead Choke cable Carburetor air vent hose Handlebar switch lead Fuel tank breather hose...
  • Page 45 SPEC CABLE ROUTING EBS00028 Pass the front brake cables, parking brake cable, throttle cable and choke cable through the hose guide. Fasten the choke cable, handlebar switch lead and rear brake switch lead with a plastic band. Insert the fuel tank breather hose into the hole in the handlebar cover. Fasten the carburetor warmer lead with a plastic band.
  • Page 46 SPEC CABLE ROUTING Fasten rear brake hose and parking brake cable with a plastic band. Fasten the fuel overflow hose and carburetor air vent hose with a metal band. Be sure to not pinch the hose. Fasten the fuel drain hose with a metal band. Be sure to not pinch the hose. Fasten the rear brake hose and choke cable with a plastic band.
  • Page 47 SPEC CABLE ROUTING Fuel drain hose Wire harness H Thermo switch Rear brake hose A Positive starter motor lead I Ignition coil Throttle cable B Positive battery lead J Rectifier/regulator Parking brake cable C Negative battery lead Starter relay Front brake cables Negative starter motor lead Battery Air filter case check hose...
  • Page 48 SPEC CABLE ROUTING Pass these leads through rear fender. Fasten the wire harness, main switch lead, thermo switch lead and with a plastic band. Fasten the wire harness and generator lead with a plastic band. Fasten the wire harness, negative battery lead and starter motor lead with a plastic band. Fasten the wire harness, positive battery lead, negative battery lead and negative starter motor lead with a metal band.
  • Page 49 SPEC CABLE ROUTING Pass the positive battery lead, positive starter motor lead and starter relay lead through the hose guide. Pass the positive battery lead through the hose guide. Pass the negative battery lead through the hose guide. Pass the positive battery lead, positive starter motor lead and wire harness through the hose guide. 2 - 27...
  • Page 50 SPEC CABLE ROUTING Rear brake switch lead Parking brake cable Negative battery lead Fuel tank breather hose Rear brake hose Handlebar switch Battery Choke cable Front brake cable (right) Positive battery lead Front brake cable (left) Throttle cable Main fuse 2 - 28...
  • Page 51 SPEC CABLE ROUTING Fasten the handlebar switch lead , rear brake switch lead and choke cable with a plastic band. Face the opening of the positive battery lead holder inward. To starter relay. Face the opening of the negative battery lead holder inward. To the frame.
  • Page 52 SPEC CABLE ROUTING Front brake cable (left) Throttle cable Handlebar switch lead Rear brake hose Oil catch hose Front brake cable (right) Rear brake switch lead Crankcase breather hose A Ignition coil Choke cable Parking brake cable B Heater control Switch Fasten the handlebar switch lead , rear brake switch lead and choke cable with a plastic band.

  • Page 53: Periodic Checks And Adjustments

    INTRODUCTION/ PERIODIC MAINTENANCE/LUBRICATION EBS00029 PERIODIC CHECKS AND ADJUSTMENTS INTRODUCTION This chapter includes all information necessary to perform recommended checks and adjustments. These preventive maintenance procedures, if followed, will ensure more reliable machine operation and a longer service life. The need for costly overhaul work will be greatly reduced. This information applies to machines already in service as well as to new machines that are being prepared for sale.
  • Page 54 Every two years replace the brake master cylinder and caliper, and change the brake fluid. Replace the brake hoses every four years and if cracked or damaged. Since these items require special tools, data and technical skills, have a Yamaha dealer perform the service.

  • Page 55: Seat, Fenders And Fuel Tank

    SEAT, FENDERS AND FUEL TANK EBS00033 SEAT, FENDERS AND FUEL TANK SEAT AND FRONT PANEL Order Job/Part Q’ty Remarks Removing the seat and front panel Remove the parts in the order listed. Seat Pull back the seat lock lever, than pull up on the rear of the seat.

  • Page 56: Front Fender

    SEAT, FENDERS AND FUEL TANK EBS00037 FRONT FENDER 9 Nm (0.9 m kg, 6.5 ft • • 25 Nm (2.5m kg,18.1 ft • • Order Job/Part Q’ty Remarks Removing the front fender Remove the parts in the order listed. Seat and front panel Refer to “SEAT AND FRONT PANEL”.

  • Page 57: Rear Fender And Footrest Boards

    SEAT, FENDERS AND FUEL TANK EBS00039 REAR FENDER AND FOOTREST BOARDS 9 Nm (0.9 m kg, 6.5 ft • • 9 Nm (0.9 m kg, 6.5 ft • • 9 Nm (0.9 m kg, 6.5 ft • • 9 Nm (0.9 m kg, 6.5 ft •...
  • Page 58 SEAT, FENDERS AND FUEL TANK 9 Nm (0.9 m kg, 6.5 ft • • 9 Nm (0.9 m kg, 6.5 ft • • 9 Nm (0.9 m kg, 6.5 ft • • 9 Nm (0.9 m kg, 6.5 ft • •...

  • Page 59: Fuel Tank

    SEAT, FENDERS AND FUEL TANK EBS00042 FUEL TANK 12 Nm (1.2 m kg, 8.7 ft • • 9 Nm (0.9 m kg, 6.5 ft • • Order Job/Part Q’ty Remarks Removing the fuel tank Remove the parts in the order listed. Seat and front panel Refer to “SEAT AND FRONT PANEL”.

  • Page 60: Engine

    ADJUSTING THE VALVE CLEARANCE EAS00049 ENGINE ADJUSTING THE VALVE CLEARANCE The following procedure applies to all of the valves. • Valve clearance adjustment should be made on a cold engine, at room tempera- ture. • When the valve clearance is to be mea- sured or adjusted, the piston must be at top dead center (TDC) on the compression stroke.
  • Page 61 ADJUSTING THE VALVE CLEARANCE c. Measure the valve clearance using a thick- ness gauge Out of specification Adjust Thickness gauge 90890-03079 Narrow gauge set YM-34483 3. Adjust: • valve clearance a. Loosen the locknut b. Insert a thickness gauge between the adjuster end and the valve end.

  • Page 62: Adjusting The Engine Idling Speed

    ADJUSTING THE ENGINE IDLING SPEED EBS00051 ADJUSTING THE ENGINE IDLING SPEED 1. Start the engine and let it warm up for sev- eral minutes. 2. Attach: • engine tachometer (to the spark plug lead) Inductive self-powered tachome- P/N. YU-8036-B Engine tachometer P/N.

  • Page 63: Adjusting The Throttle Lever Free Play

    ADJUSTING THE THROTTLE LEVER FREE PLAY EBS00052 ADJUSTING THE THROTTLE LEVER FREE PLAY Engine idling speed should be adjusted prop- erly before adjusting the throttle lever free play. 1. Measure: • throttle lever free play Out of specification → Adjust. Throttle lever free play 1.0 ~ 3.0 mm (0.04 ~ 0.12 in) 2.

  • Page 64: Adjusting The Speed Limiter

    ADJUSTING THE SPEED LIMITER EBS00053 ADJUSTING THE SPEED LIMITER The speed limiter keeps the carburetor throttle from becoming fully-opened even when the throttle lever is applied to the maximum posi- tion. Screwing in the adjuster stops the engine speed from increasing. 1.

  • Page 65: Checking The Spark Plug

    CHECKING THE SPARK PLUG EBS00057 CHECKING THE SPARK PLUG 1. Remove: • spark plug 2. Check: • spark plug type Incorrect → Change. Standard spark plug CR7HSA/NGK 3. Check: • electrode Wear/damage → Replace. • insulator Abnormal color → Replace. Normal color is a medium-to-light tan color.

  • Page 66: Checking The Ignition Timing

    CHECKING THE IGNITION TIMING EBS00058 CHECKING THE IGNITION TIMING Engine idling speed and throttle cable free play should be adjusted properly before checking the ignition timing. 1. Remove: • Shroud cap 2. Attach: • engine tachometer • timing light (to spark plug lead) Inductive self-powered tachome- P/N.

  • Page 67: Measuring The Compression Pressure

    MEASURING THE COMPRESSION PRESSURE EBS00061 MEASURING THE COMPRESSION PRESSURE Insufficient compression pressure will result in a loss of performance. 1. Measure: • valve clearance Out of specification → Adjust. Refer “ADJUSTING VALVE CLEARANCE”. 2. Start the engine, warm it up for several min- utes, and then turn it off.
  • Page 68 MEASURING THE COMPRESSION PRESSURE a. Set the main switch to “ON”. b. With the throttle wide open, crank the engine until the reading on the compression gauge stabilizes. WARNING To prevent sparking, ground the spark plug lead before cranking the engine. c.

  • Page 69: Checking The Engine Oil Level

    CHECKING THE ENGINE OIL LEVEL EBS00064 CHECKING THE ENGINE OIL LEVEL 1. Place the machine on a level surface. 2. Check: • engine oil level Oil level should be between the maximum mark and minimum mark. → Oil level low Add oil to the proper level.

  • Page 70: Changing The Engine Oil

    CHANGING THE ENGINE OIL EBS00068 CHANGING THE ENGINE OIL 1. Start the engine, warm it up for several min- utes, and then turn it off. 2. Place a container under the engine oil drain bolt. 3. Remove: • dipstick • engine oil drain bolt (along with the O-ring, spring and oil filter screen) 4.

  • Page 71: Cleaning The Air Filter Element

    CLEANING THE AIR FILTER ELEMENT EBS00071 CLEANING THE AIR FILTER ELEMENTS There is a check hose at the bottom of the air filter case. If dust and/or water collects in this hose, clean the air filter elements and air fil- ter case.

  • Page 72: Cleaning The Spark Arrester

    NOTICE Do not twist or wring out the sponge materials. could damage the sponge materials. c. Apply Yamaha foam air filter oil or other quality foam air filter oil to the sponge materials. d. Squeeze out the excess oil. The sponge materials should be wet but not dripping.
  • Page 73 CLEANING THE SPARK ARRESTER c. Tap the tailpipe lightly with a soft-face ham- mer or suitable tool, then use a wire brush to remove any carbon deposits from the spark arrester portion of the tailpipe and the inner contact surfaces of the muffler. d.

  • Page 74: Chassis

    CHECKING THE FRONT BRAKE SHOES ADJUSTING THE FRONT BRAKE CHASSIS CHECKING THE FRONT BRAKE SHOES 1. Check: • Upper adjusting bolt • Lower adjusting bolt → Replace more than 12 mm (0.47 in) the brake shoes as a set. Refer to “FRONT BRAKES” in chapter 6. EBS00082 ADJUSTING THE FRONT BRAKE Before adjusting the front brake, the front...

  • Page 75: Adjusting The Parking Brake

    ADJUSTING THE PARKING BRAKE ADJUSTING THE PARKING BRAKE 1. Check: • parking brake cable end length Out of specification → Adjust. Parking brake cable end length 53.0 ~ 57.0 mm (2.09 ~ 2.24 in) 2. Adjust: • parking brake cable end length a.

  • Page 76: Checking The Rear Brake Fluid Level

    CHECKING THE REAR BRAKE FLUID LEVEL EBS00087 CHECKING THE REAR BRAKE FLUID LEVEL 1. Place the machine on a level surface. When checking the brake fluid level, make sure that the top of the brake master cylinder reser- voir or brake fluid reservoir is horizontal. 2.

  • Page 77: Checking The Rear Brake Pads

    CHECKING THE REAR BRAKE PADS/CHECKING THE BRAKE HOSE/ BLEEDING THE HYDRAULIC BRAKE SYSTEM EBS00089 CHECKING THE REAR BRAKE PADS 1. Check: • brake pads Wear indicators almost touch the brake disc → Replace the brake pads as a set. Refer to “REAR BRAKE” in chapter 6. Brake pad wear limit 1.0 mm (0.04 in) 2.
  • Page 78 BLEEDING THE HYDRAULIC BRAKE SYSTEM • Be careful not to spill any brake fluid or allow the brake master cylinder reservoir or brake fluid reservoir to overflow. • When bleeding the hydraulic brake system, make sure there is always enough brake fluid before applying the brake.

  • Page 79: Changing The Final Transmission Oil

    CHANGING THE FINAL TRANSMISSION OIL/ ADJUSTING THE DRIVE CHAIN SLACK EBS00102 CHANGING THE FINAL TRANSMISSION OIL 1. Place the machine on a level surface. 2. Place a receptacle under the final transmission case. 3. Remove: • dipstick • final transmission oil drain plug 4.
  • Page 80 ADJUSTING THE DRIVE CHAIN SLACK 1. Measure: • drive chain slack Out of specification → Adjust. Drive chain slack 10 ~ 25 mm (0.39 ~ 0.98 in) 2. Adjust: • drive chain slack The drive chain slack is adjusted by the rota- tion of the rear axle hub.

  • Page 81: Checking The Steering System

    CHECKING THE STEERING SYSTEM EBS00107 CHECKING THE STEERING SYSTEM 1. Place the machine on a level surface. 2. Check: • steering shaft bushings and bearings Move the handlebar up and down, and/or back and forth. Excessive play → Replace the steering shaft bushings and or bearings.

  • Page 82: Adjusting The Toe-In

    ADJUSTING THE TOE-IN EBS00108 ADJUSTING THE TOE-IN 1. Place the machine on a level surface. 2. Measure: • toe-in Out of specification → Adjust. Toe-in 15 mm (0.59 in) Before measuring the toe-in, make sure that the tire pressure is correct. a.

  • Page 83: Checking The Front And Rear Shock Absorbers

    ADJUSTING THE TOE-IN/CHECKING THE FRONT AND REAR SHOCK ABSORBERS a. Mark both tie-rods ends. This reference point will be needed during adjustment. b. Loosen the locknuts (tie-rod end) of both tie-rods. c. The same number of turns should be given to both the right and left tie-rods until the specified toe-in is obtained.

  • Page 84: Adjusting The Shock Absorbers

    ADJUSTING THE SHOCK ABSORBERS EBS00111 ADJUSTING THE SHOCK ABSORBERS WARNING Always adjust the spring preload of both front shock absorbers to the same setting. Uneven adjustment can result in poor han- dling and loss of stability. 1. Adjust: • spring preload a.

  • Page 85: Checking The Tires

    • TIRE CHARACTERISTICS 1) Tire characteristics influence the han- dling of ATVs. The tires listed below have been approved by Yamaha Motor Co., Ltd. for this model. If other tire com- binations are used, they can adversely affect your machine’s handling charac- teristics and are therefore not recom- mended.

  • Page 86: Checking The Tires

    CHECKING THE TIRES 1. Measure: • tire pressure Out of specification → Adjust. • The low-pressure tire gauge is included as standard equipment. • If dust or the like is stuck to this gauge, it will not provide the correct readings. Therefore, take two measurements of the tire’s pressure and use the second reading.

  • Page 87: Checking The Wheels

    CHECKING THE TIRES/ CHECKING THE WHEELS 2. Check: • tire surfaces Wear/damage → Replace. Tire wear limit Front and rear: 3 mm (0.12 in) WARNING It is dangerous to ride with a worn-out tire. When tire wear is out of specification, replace the tire immediately.

  • Page 88: Checking And Lubricating The Cables

    CHECKING AND LUBRICATING THE CABLES/LUBRICATING THE LEVERS, STEERING SHAFT AND STEERING KNUCKLES EBS00117 CHECKING AND LUBRICATING THE CABLES WARNING A damaged cable sheath may cause corro- sion and interfere with the cable move- ment. An unsafe condition may result so replace a damaged cable as soon as possi- ble.

  • Page 89: Electrical System

    CHECKING AND CHARGING THE BATTERY EBS00120 ELECTRICAL SYSTEM CHECKING AND CHARGING THE BATTERY 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 90 CHECKING AND CHARGING THE BATTERY Since VRLA (Valve Regulated Lead Acid) batteries are sealed, it is not possible to check the charge state of the battery by measuring the specific gravity of the electrolyte. Therefore, the charge of the battery has to be checked by measuring the voltage at the battery terminals.
  • Page 91 CHECKING AND CHARGING THE BATTERY Example c. Open-circuit voltage = 12.0 V d. Charging time = 6.5 hours e. Charge of the battery = 20 ~ 30% 5. Charge: Charging Ambient temperature 20°C (68°F) • battery (refer to the appropriate charging method illustration) WARNING Do not quick charge a battery.
  • Page 92 CHECKING AND CHARGING THE BATTERY • As shown in the following illustration, the open-circuit voltage of an VRLA (Valve Regulated Lead Acid) battery stabilizes about 30 minutes after charging has been completed. Therefore, wait 30 minutes after charging is completed before measuring the open-circuit voltage.
  • Page 93 CHECKING AND CHARGING THE BATTERY Charging method using a variable-current (voltage) charger Charger Ammeter Measure the open-circuit Leave the battery unused for voltage prior to charging. more than 30 minutes before measuring its open-circuit voltage. Connect a charger and ammeter to the battery Set the charging voltage to 16 ~ 17 V.
  • Page 94 CHECKING AND CHARGING THE BATTERY Charging method using a constant voltage charger Measure the open-circuit Leave the battery unused for more voltage prior to charging. than 30 minutes before measuring its open-circuit voltage. Connect a charger and ammeter to the battery and start charging.
  • Page 95 CHECKING AND CHARGING THE BATTERY 6. Install: • battery 7. Connect: • battery leads (to the battery terminals) NOTICE First, connect the positive battery lead and then the negative battery lead 8. Check: • battery terminals Dirt → Clean with a wire brush. Loose connection →...

  • Page 96: Checking The Fuses

    CHECKING THE FUSES EBS00121 CHECKING THE FUSES The following procedure applies to all of the fuses. NOTICE To avoid a short circuit, always set the main switch to “OFF” when checking or replac- ing a fuse. 1. Remove: • seat Refer to “SEAT, FENDERS AND FUEL TANK”.
  • Page 97 CHECKING THE FUSES Amperage Items Q’ty rating Main 10 A Reserve 10 A WARNING Never use a fuse with an amperage rating other than that specified. Improvising or using a fuse with the wrong amperage rat- ing may cause extensive damage to the electrical system, cause the lighting and ignition systems to malfunction and could possibly cause a fire.

  • Page 98: Engine

    ENGINE EBS00198 ENGINE ENGINE EXHAUST PIPE/MUFFLER, BREATHER HOSE AND LEADS 13 Nm (1.3 m kg, 9.4 ft 25 Nm (2.5 m kg, 18 ft • • • • Order Job/Part Q’ty Remarks Removing the exhaust pipe/muffler, Remove the parts in the order listed. breather hose and leads Rear fender Refer to “SEAT, FENDERS AND FUEL...

  • Page 99: Engine Mounting Bolts

    ENGINE EBS00205 ENGINE MOUNTING BOLTS 35 Nm (3.5 m kg, 23.5 ft • • 35 Nm (3.5 m kg, 23.5 ft • • Order Job/Part Q’ty Remarks Removing the engine mounting Remove the parts in the order listed. bolts Carburetor Refer to “CARBURETOR”...

  • Page 100: Removing The Engine

    ENGINE REMOVING THE ENGINE Remove: • master link • drive chain EBS00207 INSTALLING THE ENGINE 1. Install: • upper engine mounting bolt/nut • lower engine mounting bolt/nut Do not fully tighten the bolts and nuts. 2. Tighten: • upper engine mounting nut 35 Nm (3.5 m ·...

  • Page 101: Cylinder Head

    CYLINDER HEAD EBS00218 CYLINDER HEAD 6 Nm (0.6 m．kg, 4.3 ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) 9Nm (0.9m．kg, 6.5ft．lb) 11Nm (1.1m．kg, 8.0ft．lb) 10Nm (1.0m．kg, 7.2ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) 9Nm (0.9m．kg, 6.5ft．lb) 15Nm (1.5m．kg, 10.8ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) Order Job/Part Q’ty Remarks Removing the cylinder head...
  • Page 102 CYLINDER HEAD 6 Nm (0.6 m．kg, 4.3 ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) 9Nm (0.9m．kg, 6.5ft．lb) 11Nm (1.1m．kg, 8.0ft．lb) 10Nm (1.0m．kg, 7.2ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) 9Nm (0.9m．kg, 6.5ft．lb) 15Nm (1.5m．kg, 10.8ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) Order Job/Part Q’ty Remarks Cyl. head cover assy. Refer to “REMOVING THE CYLINDER Cap, camshaft HEAD”...
  • Page 103 CYLINDER HEAD EBS00220 REMOVING THE CYLINDER HEAD 1. Align: • “T” mark on the rotor (with the stationary pointer on the crank- case) a. Turn the crankshaft clockwise with a wrench. b. Align the “T” mark on the rotor with the stationary pointer on the crankcase.

  • Page 104: Checking The Camshaft Sprocket

    CYLINDER HEAD 3. Remove: cam shaft comp. • head assy. • cyl. Fasten a safety wire to the timing chain to prevent it from falling into crankcase. EBS00224 CHECKING THE CAMSHAFT SPROCKET 1. Check: • camshaft sprocket → Replace the More than 1/4 tooth wear cam shaft comp.

  • Page 105: Checking The Cylinder Head

    CYLINDER HEAD EBS00230 CHECKING THE CYLINDER HEAD 1. Eliminate: • combustion chamber carbon deposits (with a rounded scraper) Do not use a sharp instrument to avoid damag- ing or scratching: • spark plug bore threads • valve seats 2. Check: •...

  • Page 106: Installing The Cylinder Head

    CYLINDER HEAD EBS00233 INSTALLING THE CYLINDER HEAD 1. Install: cyl. head assy. 1 • cam shaft comp. • cap, camshaft • washer • • Tighten the nuts in two stages and a crisscross pattern. 2. Install: • cam shaft comp. round h- a.
  • Page 107 CYLINDER HEAD i. If the marks are aligned, temporarily tighten the camshaft sprocket bolt. If the marks are not aligned, change the meshing position of the camshaft sprocket and timing chain. 3. Install: bolt, flg. (small head) • • tensioner assy. WARNING Always use a new gasket.

  • Page 108: Camshaft, Rocker Arms And Valves

    CAMSHAFT, ROCKER ARMS AND VALVES EBS00235 CAMSHAFT, ROCKER ARMS AND VALVES 9Nm (0.9m．kg, 6.5ft．lb) 9Nm (0.9m．kg, 6.5ft．lb) Order Job/Part Q’ty Remarks Removing the camshaft, rocker Remove the parts in the order listed. arms and valves Cylinder head Refer to “CYLINDER HEAD”. Cam shaft comp.

  • Page 109: Removing The Rocker Arms And Camshaft

    CAMSHAFT, ROCKER ARMS AND VALVES EBS00237 REMOVING THE ROCKER ARMS AND CAMSHAFT 1. Loosen: • locknuts • screw, valve adjusting 2. Remove: • intake rocker arm shaft • exhaust rocker arm shaft • intake rocker arm • exhaust rocker arm Remove the rocker arm shafts with the slide hammer bolt and weight...

  • Page 110: Checking The Camshaft

    CAMSHAFT, ROCKER ARMS AND VALVES 2. Remove: • valve cotters Attach a valve spring compressor attachment between the valve spring retainer and the cylinder head to remove the valve cotters. Valve spring compressor P/N. YM-04019, 90890-04019 Valve spring compressor attach- ment P/N.
  • Page 111 CAMSHAFT, ROCKER ARMS AND VALVES 2. Check: • rocker arm shaft Blue discoloration/excessive wear/pitting/ scratches → Replace or check the lubrica- tion system. 3. Check: • camshaft lobe Excessive wear → Replace the camshaft. 4. Measure: • rocker arm inside diameter Out of specification →...

  • Page 112: Checking The Valves And Valve Springs

    CAMSHAFT, ROCKER ARMS AND VALVES EBS00240 CHECKING THE VALVES AND VALVE SPRINGS 1. Measure: • stem-to-guide clearance Stem-to-guide clearance = valve guide inside diameter – valve stem diameter → Out of specification Replace the cylinder head ass'y. Stem-to-guide clearance Intake 0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in) <Limit>: 0.08 mm (0.0031 in)
  • Page 113 CAMSHAFT, ROCKER ARMS AND VALVES 2. Check: • valve face Pitting/wear → Grind the face. • valve stem end Mushroom shape or diameter larger than the body of the stem → Replace. 3. Measure: • margin thickness Out of specification → Replace. Margin thickness Intake 0.5 ~ 0.9 mm...
  • Page 114 CAMSHAFT, ROCKER ARMS AND VALVES 7. Measure: • valve seat width Out of specification → Reface the valve seat. Valve seat width Intake 0.8 ~ 1.1 mm (0.0315 ~ 0.0433 in) <Limit>: 1.6 mm (0.063 in) Exhaust 0.8 ~ 1.1 mm (0.0315 ~ 0.0433 in) <Limit>: 1.6 mm (0.063 in) a.
  • Page 115 CAMSHAFT, ROCKER ARMS AND VALVES b. Apply molybdenum disulfide oil to the valve stem. c. Install the valve into the cylinder head. d. Turn the valve until the valve face and valve seat are evenly polished, then clean off all of the compound.

  • Page 116: Installing The Valves And Valve Springs

    CAMSHAFT, ROCKER ARMS AND VALVES 11.Measure: • spring tilt Out of specification → Replace. Spring tilt limit Inner 2.0°/1.2 mm(2.0°/0.05 in) EBS00241 INSTALLING THE VALVES AND VALVE SPRINGS 1. Apply: • molybdenum disulfide oil (onto the valve stem and valve stem seal) 2.

  • Page 117: Installing The Camshaft And Rocker Arms

    CAMSHAFT, ROCKER ARMS AND VALVES EBS00243 INSTALLING THE CAMSHAFT AND ROCKER ARMS 1. Install: • camshaft comp. Be sure to align the round hole in camshaft sprocket away from the cylinder head. 2. Apply: • engine oil (onto the rocker arm shafts) 3.

  • Page 118: Cylinder And Piston

    CYLINDER AND PISTON CYLINDER AND PISTON EBS00245 CYLINDER AND PISTON 12Nm (1.2m．kg, 8.7ft．lb) Order Job/Part Q’ty Remarks Removing the cylinder and piston Remove the parts in the order listed. Cylinder head Refer to “CYLINDER HEAD”. Cylinder Refer to “INSTALLING THE CYLINDER”. Cylinder gasket Dowel pin Piston pin clip...

  • Page 119: Removing The Piston

    CYLINDER AND PISTON EBS00247 REMOVING THE PISTON 1. Remove: • piston pin clips • piston pin • piston • Before removing the piston pin clip, cover the crankcase opening with a clean rag to prevent the piston pin clip from falling into the crankcase. •...
  • Page 120 CYLINDER AND PISTON 47.00 ~ 47.01 mm Cylinder bore “C” (1.8504 ~ 1.8508 in) Taper limit “T” 0.05 mm (0.002 in) Out-of-round “R” 0.01 mm (0.0004 in) “C” = maximum of D “T” = maximum of D or D – maximum of D or D “R”...

  • Page 121: Checking The Piston Rings

    CYLINDER AND PISTON EBS00250 CHECKING THE PISTON RINGS 1. Measure: • piston ring side clearance Out of specification → Replace the piston and piston rings as a set. Before measuring the piston ring side clear- ance, eliminate any carbon deposits from the piston ring grooves and piston rings.

  • Page 122: Checking The Piston Pin

    CYLINDER AND PISTON EBS00251 CHECKING THE PISTON PIN 1. Check: • piston pin Blue discoloration/grooves → Replace the piston pin and then check the lubrication system. 2. Measure: • piston pin outside diameter Out of specification → Replace the piston pin.

  • Page 123: Installing The Piston

    CYLINDER AND PISTON EBS00252 INSTALLING THE PISTON 1. Install: • piston rings (onto the piston) • Be sure to install the piston rings so that the manufacturer’s marks numbers located on the upper side of the rings. • Lubricate the piston and piston rings liberally with engine oil.

  • Page 124: Installing The Cylinder

    CYLINDER AND PISTON EBS00253 INSTALLING THE CYLINDER 1. Install: • cylinder Install the cylinder with one hand while com- pressing the piston rings with the other hand. NOTICE • Be careful not to damage the timing chain damper during installation. •...

  • Page 125: C.d.i. Magneto

    C.D.I. MAGNETO EBS00256 C.D.I. MAGNETO 5 Nm (0.5 m • kg, 3.6 ft • Ib) 12 Nm (1.2 m • kg, 8.7 ft • Ib) 10 Nm (1.0 m • kg, 7.2 ft • Ib) 55 Nm (5.5 m • kg, 40 ft • Ib) Order Job/Part Q’ty...

  • Page 126: Removing The C.d.i. Magneto Rotor

    C.D.I. MAGNETO EBS00259 REMOVING THE C.D.I. MAGNETO ROTOR 1. Remove: plate washer While holding the C.D.I. magneto rotor with the holding tool , loosen the C.D.I. mag- neto nut . Do not allow the sheave holder to touch the projection on the C.D.I. magneto rotor. Rotor holding tool 90890-01235 (YU-01235) 2.

  • Page 127: Checking The Pickup Coil/Stator Assembly

    C.D.I. MAGNETO INSTALLING THE PICKUP COIL AND STATOR ASSEMBLY Install tator assembly Align the “black tape ” on the stator ass- embly with the bolt on the crankcase. Install ickup coil The s tator assembly cable be passed through between bolt and bolt hole EBS00268 INSTALLING THE C.D.I.

  • Page 128: Belt Drive

    BELT DRIVE EAS00316 BELT DRIVE CRANKCASE COVER 12Nm (1.2m • kg, 8.7ft • lb) Order Job/Part Q’ty Remarks Removing the belt drive Remove the parts in the order listed. Kickstarter Crankcase cover - 1 Dowel pin For installation, reverse the removal pro- cedure.
  • Page 129 BELT DRIVE EAS00338 KICKSTARTER Order Job/Part Q’ty Remarks Removing the kickstarter Remove the parts in the order listed. Crankcase, cover Refer to “CRANKCASE COVER “. Refer to“INSTALLINGTHE KICKSTARTER“. Kick pinion gear clip Kick pinion gear Washer Circlip Washer Kick shaft assembly Torsion spring Spacer Solid bush...

  • Page 130: Installing The Kickstarter

    BELT DRIVE EAS00340 INSTALLING THE KICKSTARTER 1. Install: solid bush kickstarter shaft kickstarter spring 2. Hook: kickstarter spring Hook the spring end on the kickstarter shaft as shown, and hook the other end on the projection 3. Install: plain washer circlip 4.

  • Page 131: V-Belt, Clutch, Primary And Secondary Sheave

    BELT DRIVE V-BELT, CLUTCH, PRIMARY AND SECONDARY SHEAVE 40Nm (4.0m．kg, 28.9ft．lb) 55Nm (5.5m．kg, 39.8ft．lb) Order Job/Part Q’ty Remarks Removing the V-belt, clutch, primary Remove the parts in the order listed. and secondary sheave Primary sheave nut / Plate washer Oneway clutch Refer to “...

  • Page 132: Disassembling The Secondary Sheave

    BELT DRIVE DISASSEMBLING THE SECONDARY SHEAVE 55Nm (5.5m．kg, 39.8ft．lb) Order Job/Part Q’ty Remarks Disassembling the secondary Disassemble the parts in the order listed. sheave Clutch carrier nut Clutch carrier Clutch shoe spring Compression spring Spring seat Refer to “ REMOVING THE SECONDARY Guide pin SHEAVE AND V-BELT “.

  • Page 133: Removing The Primary Sheave

    BELT DRIVE EAS00317 REMOVING THE PRIMARY SHEAVE 1. Remove: primary sheave nut plate washer oneway clutch primary fixed sheave - 1 primary fixed sheave - 2 collar primary sliding sheave While holding the primary fixed sheave with the rotor holding tool , loosen the primary fixed sheave nut.

  • Page 134: Disassembling The Secondary Sheave

    BELT DRIVE 3. Remove: secondary sheave assembly V-belt Remove the V-belt and clutch assembly from the primary sheave side. EAS00319 DISASSEMBLINGTHE SECONDARY SHEAVE 1. Remove: clutch carrier nut Install the clutch spring holder and clutch spring holder arm onto the secondary sheave as shown.

  • Page 135: Checking The V-Belt

    BELT DRIVE EAS00320 CHECKING THE V-BELT 1. Check: V-belt Cracks/damage/wear Replace. Grease/oil Clean the primary and sec- ondary sheave. 2. Measure: V-belt width Out of specification Replace. V-belt width 18.0 mm (0.708 in) <Limit>: 17.0 mm (0.669 in) CHECKING THE PRIMARY SHEAVE 1.

  • Page 136: Checking The Slider

    BELT DRIVE CHECKING THE SLIDER Check: slider Damage/wear Replace EAS00322 CHECKING THE SECONDARY SHEAVE 1. Check: secondary fixed sheave secondary sliding sheave Cracks/damage/wear Replace the sec- ondary fixed and sliding sheaves as a set. 2. Check: torque cam groove Damage/wear Replace the secondary fixed and sliding sheaves as a set.

  • Page 137: Assembling The Primary Sheave

    BELT DRIVE EAS00323 ASSEMBLING THE PRIMARY SHEAVE 1. Clean: primary fixed sheave primary sliding sheave collar primary sheave weights Use thinner to clean up grease, dirt on the pri- mary sliding sheave cam side 2. Install: primary sheave weights collar 3.

  • Page 138: Assembling The Secondary Sheave

    BELT DRIVE EAS00324 ASSEMBLING THE SECONDARY SHEAVE 1. Lubricate: secondary fixed sheave’s inner surface secondary sliding sheave’s inner surface torque cam groove oil seals bearings (with the recommended lubricant) Recommended lubricant BEL-RAY assembly lube 2. Install: secondary sliding sheave Install the secondary sliding sheave onto the secondary fixed sheave with the oil seal guide Oil seal guide...

  • Page 139: Installing The Belt Drive

    BELT DRIVE 5. Install: secondary sheave spring clutch carrier Attach the clutch spring holder and clutch spring holder arm onto the secondary sheave as shown. Then, compress the spring, and tighten the clutch carrier nut Clutch spring holder 90890-01337 (YM-33285) ( YM-33285-6) EAS00325 INSTALLING THE BELT DRIVE...
  • Page 140 BELT DRIVE 2. Install: clutch carrier nut 55 Nm (5.5 m • kg, 39.8 ft • lb) While holding the clutch carrier with the rotor holding tool , tighten the clutch carrier nut with the locknut wrench Rotor holding tool 90890-01235 Locknut wrench 90890-01348 (YM-01348)

  • Page 141: Starter Clutch And Starter Motor

    STARTER CLUTCH AND STARTER MOTOR STARTER CLUTCH AND STARTER MOTOR 12Nm (1.2m．kg, 8.7ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) Order Job/Part Q’ty Remarks Removing the starter clutch and Disassemble the parts in the order listed. starter motor Primary sheave Refer to “ REMOVING THE PRIMARY SHEAVE “...

  • Page 142: Checking The Starter Wheel Gear

    STARTER CLUTCH AND STARTER MOTOR CHECKING THE STARTER WHEEL GEAR 1. Check: starter wheel gear idle gear Burrs/chips/roughness/wear Replace 2. Check: starter clutch operation a. Install the starter wheel gear onto the idle gear and hold the starter clutch. b. When turning the starter wheel gear clock- wise , the starter clutch and the starter wheel gear should engage, otherwise the...

  • Page 143: Oil Pump

    OIL PUMP EBS00315 OIL PUMP 12 Nm (1.2 m • kg, 8.7 ft • Ib) Order Job/Part Q’ty Remarks Disassembling the oil pump Remove the parts in the order listed. C.D.I. magneto Refer to “ C.D.I. MAGNETO “ Cover O-ring Oil seal Dowel pin Oil pump driven gear...

  • Page 144: Checking The Oil Pump

    OIL PUMP EAS00364 CHECKING THE OIL PUMP 1. Check: oil pump driven gear Cracks/damage/wear Replace the de- fective part(s). 2. Measure: inner-rotor-to-outer-rotor-tip clearance outer-rotor-to-oil-pump-housing clear- ance oil-pump-housing-to-inner-rotor-and- outer-rotor clearance Out of specification Replace the oil pump. Inner rotor Outer rotor Oil pump housing Inner-rotor-to-outer-rotor-tip clear- ance...

  • Page 145: Installing The Oil Pump

    OIL PUMP 3. Check: oil pump operation Rough movement Repeat steps (1) and (2) or replace the defective part(s). EAS00376 INSTALLING THE OIL PUMP 1. Install: o-ring oil pump assembly oil pump bolt 12 Nm (1.2 m • kg, 8.7 ft • lb) NOTICE After tightening the bolts, make sure the oil pump turns smoothly.

  • Page 146: Crankcase And Crankshaft

    CRANKCASE AND CRANKSHAFT EBS00319 CRANKCASE AND CRANKSHAFT 12Nm (1.2m．kg, 8.7ft．lb) Order Job/Part Q’ty Remarks Removing the crankshaft assembly Remove the parts in the order listed. Engine Refer to “ ENGINE “. Cylinder head Refer to “CYLINDER HEAD “. Cylinder piston Refer to “CYLINDER AND PISTON “.
  • Page 147 CRANKCASE AND CRANKSHAFT EBS00333 SEPARATING THE CRANKCASE 1. Remove: • crankcase bolt 2. Remove: • right crankcase Tap on one side of the crankcase with a soft- face hammer . Tap only on reinforced portions of the crankcase, not on the crankcase mating surfaces.

  • Page 148: Checking The Timing Chain And Timing Chain Guides

    CRANKCASE AND CRANKSHAFT EAS00389 REMOVING THE CRANKSHAFT ASSEMBLY 1. Remove: • crankshaft assembly • timing chain • Before removing the crankshaft assembly, remove the timing chain from the crankshaft sprocket. • The crankshaft assembly cannot be re- moved if the timing chain is attached onto the crankshaft sprocket.

  • Page 149: Checking The Crankshaft And Connecting Rod

    CRANKCASE AND CRANKSHAFT EAS00394 CHECKING THE CRANKSHAFT AND CON- NECTING ROD 1. Measure: • crankshaft runout Out of specification Replace the crank- shaft, bearing or both. Turn the crankshaft slowly. Maximum crankshaft runout 0.04 mm (0.0016 in) 2. Measure: • big end side clearance Out of specification Replace the big end...

  • Page 150: Installing The Crankshaft

    CRANKCASE AND CRANKSHAFT 5. Check: • crankshaft journal Scratches/wear Replace the crank- shaft. EAS00408 INSTALLING THE CRANKSHAFT 1. Install: • crankshaft assembly • crankcase • timing chain NOTICE To avoid scratching the crankshaft and to ease the installation procedure, lubricate the oil seal lips with lithium-soap-based grease and each bearing with engine oil.

  • Page 151: Assembling The Crankcase

    CRANKCASE AND CRANKSHAFT EAS00418 ASSEMBLING THE CRANKCASE 1. Thoroughly clean all the gasket mating sur- faces and crankcase mating surfaces. 2. Install: • crankcase gasket (onto the crankcase mating surfaces) 3. Install: • dowel pins • timing chain Install the timing chain so it is not visible through the opening in the left crankcase 4.

  • Page 152: Transmission

    TRANSMISSION EAS00419 TRANSMISSION 10Nm(1.0m kg, 7.2 ft lb) • • 25Nm(2.5m kg, 18.0 ft • • Order Job/Part Q’ty Remarks Removing the lock washer, drive Remove the parts in the order listed. sprocket, and circlip Transmission oil Drain. Refer to “BELT DRIVE “. Crankcase cover Refer to “V-BELT, CLUTCH, PRIMARY Belt drive...

  • Page 153: Checking The Transmission

    TRANSMISSION EAS00425 CHECKING THE TRANSMISSION 1. Measure: • main axle runout (with a centering device and dial gauge ) Out of specification Replace the main axle. Main axle runout limit 0.08 mm (0.0031 in) 2. Measure: • primary drive gear shaft runout (with a centering device and dial gauge ) Out of specification Replace the drive...

  • Page 154: Carburetor

    CARB CARBURETOR EBS00141 CARBURETOR CARBURETOR Order Job/Part Q’ty Remarks Removing the carburetor Remove the parts in the order listed. Fuel overflow hose Air vent hose Fuel drain hose Fuel hose Carburetor assembly Plate Plunger assay, starter Spring Manual starter comp Wire,starter Throttle cable cover Throttle cable...

  • Page 155: Disassembling The Carburetor

    CARB CARBURETOR EBS00144 Order Job/Part Q’ty Remarks Disassembling the carburetor Remove the parts in the order listed. Before disassembling the carburetor, make sure to note the number of times the pilot screw is turned out from the seated position to its set position. Throttle stop screw Cover Spring...
  • Page 156 CARB CARBURETOR Order Job/Part Q’ty Remarks Disassembling the carburetor Remove the parts in the order listed. Carburetor warmer negative lead Float chamber Spring Acceleration pump comp Float pin Float Needle valve Main jet Needle jet holder Needle jet Pilot jet Plug For assembly, reverse the disassembly procedure.

  • Page 157: Checking The Carburetor

    CARB CARBURETOR EBS00146 DISASSEMBLING THE CARBURETOR Before disassembling the carburetor, make sure to note the number of times the pilot screw is turned out from the seated position to its set position. EAS00485 CHECKING THE CARBURETOR 1. Check: • carburetor body •...
  • Page 158 CARB CARBURETOR 4. Check: • piston valve Damage/scratches/wear Replace. • piston valve diaphragm Cracks/tears Replace. 5. Check: • vacuum chamber cover • piston valve spring Cracks/damage Replace. Check: • jet needle • main jet • Needle jet holder • Needle jet •...

  • Page 159: Assembling The Carburetor

    CARB CARBURETOR 9. Check: • throttle valve movement Sticks Replace. 10. Check: • choke valve movement Sticks → Replace. 11. Check: • starter plunger • starter plunger spring Bends/cracks/damage → Replace. EBS00150 ASSEMBLING THE CARBURETOR Before assembling the carburetor, make sure to turn out the pilot air screw the same number of times, as noted before disassembly, from the seated position to the set position.

  • Page 160: Installing The Carburetor

    CARB CARBURETOR 2. Install: • float • needle valve • float pin 3. Install: • accelerator pump assembly 4. Install: • piston valve • jet needle • piston valve spring • vacuum chamber cover EAS00492 INSTALLING THE CARBURETOR 1. Adjust: •...

  • Page 161: Measuring And Adjusting The Fuel Level

    CARB CARBURETOR EBS00154 MEASURING AND ADJUSTING THE FUEL LEVEL 1. Measure: • fuel level Out of specification → Adjust. Fuel level (above the float chamber mating surface) 5.0 ~ 6.0 mm (0.20 ~ 0.24 in) a. Stand the machine on a level surface. b.

  • Page 162: Front And Rear Wheels

    CHAS FRONT AND REAR WHEELS EBS00378 CHASSIS FRONT AND REAR WHEELS FRONT WHEELS 65 Nm (6.5 m kg, 47 ft • • 45 Nm (4.5 m kg, 32.5 ft • • Order Job/Part Q’ty Remarks Removing the front wheels Remove the parts in the order listed. Place the machine on a level surface.

  • Page 163: Rear Wheels

    CHAS FRONT AND REAR WHEELS EBS00379 REAR WHEELS 45 Nm (4.5 m kg, 32.5 ft • • 135 Nm (13.5 m kg, 97.6 ft • • Order Job/Part Q’ty Remarks Removing the rear wheels Remove the parts in the order listed. Place the machine on a level surface.

  • Page 164: Checking The Wheels

    CHAS FRONT AND REAR WHEELS EBS00383 CHECKING THE WHEELS The following procedure applies to both of the front and rear wheels. 1. Check: • wheel 2. Measure: • wheel runout Over the specified limit → Replace the wheel or check the wheel bearing play Wheel runout limit Radial : 2.0 mm (0.08 in)

  • Page 165: Checking The Rear Wheel Hubs

    CHAS FRONT AND REAR WHEELS WARNING Eye protection is recommended when using striking tools. c. To install the wheel bearings, reverse the above sequence. Use a socket that matches outside diameter of bearing outer race to drive in bearing. NOTICE Do not strike the center race or balls of the bearing.

  • Page 166: Installing The Front Wheels

    CHAS FRONT AND REAR WHEELS INSTALLING THE FRONT WHEELS The following procedure applies to both of the front wheels. 1. Install: • wheel The arrow mark on the tire must point in the direction of rotation of the wheel. 2. Tighten: •...

  • Page 167: Front Brakes

    CHAS FRONT BRAKES FRONT BRAKES FRONT BRAKES FRONT BRAKES 14 Nm (1.4 m kg, 10.1 ft • • Order Job/Part Q’ty Remarks Removing the front brakes Remove the parts in the order listed. Refer to “FRONT AND REAR WHEELS”. The following procedure applies to both of the front brakes.

  • Page 168: Removing The Front Brakes

    CHAS FRONT BRAKES REMOVING THE FRONT BRAKES The following procedure applies to each brake. 1. Remove: • brake camshaft lever • brake camshaft When removing the brake camshaft lever, mark the position on the brake camshaft lever where it is aligned with the punch mark in the brake camshaft.

  • Page 169: Checking The Front Brake Drums

    CHAS FRONT BRAKES 2. Check: • brake shoe lining surface Glazed areas → Remove. Use coarse sandpaper. After using sandpaper, wipe off the polished particles with a cloth. 3. Measure: • brake shoe lining thickness Out of specification → Replace. Measuring points Replace the brake shoes as a set if either is found to be worn to the wear limit.

  • Page 170: Installing The Front Brakes

    CHAS FRONT BRAKES 2. Check: • brake drum inner surface Oil/scratches → Remove. Use a rag soaked in lacquer thinner or solvent. Use an emery cloth (light Scratches and even polishing). EBS00442 INSTALLING THE FRONT BRAKES The following procedure applies to both of the front brakes.
  • Page 171 CHAS FRONT BRAKES 3. Install: • brake shoe plate When installing the brake shoe plate, align the groove of the brake shoe plate with the pro- jection of the steering knuckle. 4. Install: • front brake cable (drum side) • brake shoes Check that the brake shoes are properly posi- tioned.

  • Page 172: Rear Axle And Rear Axle Hub

    CHAS REAR AXLE AND REAR AXLE HUB EBS00382 REAR AXLE AND REAR AXLE HUB 170 Nm (17.0 m kg, 123 ft • • 60 Nm (6.0 m · kg, 43.4 ft · lb) 35 Nm (3.5 m kg, 25.3 ft •...
  • Page 173 CHAS REAR AXLE AND REAR AXLE HUB 170 Nm (17.0 m kg, 123 ft • • 60 Nm (6.0 m · kg, 43.4 ft · lb) 35 Nm (3.5 m kg, 25.3 ft • • 65 Nm (6.5 m kg, 47.0 ft •...

  • Page 174: Removing The Rear Axle

    CHAS REAR AXLE AND REAR AXLE HUB EBS00393 REMOVING THE REAR AXLE 1. Place the machine on a level surface. 2. Straight • lock washer 3. Remove: • lock washer • nuts • Apply the brake lever so that the rear axle does not turn, when loosening the nut.

  • Page 175: Checking The Rear Axle

    CHAS REAR AXLE AND REAR AXLE HUB CHECKING THE REAR AXLE 1. Check: • rear axle runout Out of specification → Replace. WARNING Do not attempt to straighten a bent axle. Rear axle runout limit 1.5 mm (0.06 in) CHECKING THE DRIVEN SPROCKET 1.

  • Page 176: Installing The Rear Axle

    CHAS REAR AXLE AND REAR AXLE HUB EBS00397 INSTALLING THE REAR AXLE 1. Tighten: • nut 60 Nm (6.0 m · kg, 43.4 ft · lb) Tighten the nut with rear axle nut wrench specification while holding the rear axle. Axle nut wrench (36 mm) 90890-01422 YM-37132...

  • Page 177: Rear Brakes

    CHAS REAR BRAKE EBS00400 REAR BRAKE REAR BRAKE PADS 35 Nm (3.5 m kg, 25.3 ft • • Order Job/Part Q’ty Remarks Removing the rear brake pads Remove the parts in the order listed. The following procedure applies to both of the rear brake calipers.

  • Page 178: Replacing The Rear Brake Pads

    CHAS REAR BRAKE EBS00402 NOTICE Disc brake components rarely require dis- assembly. DO NOT: • disassemble components unless abso- lutely necessary; • use solvents on internal brake compo- nents; • use spent brake fluid for cleaning; (use only clean brake fluid) •...
  • Page 179 CHAS REAR BRAKE c. Tighten the brake caliper bleed screw. 8 Nm (0.8 m•kg, 5.8 ft•lb) d. Install a new brake pad spring and new brake pads. 3. Install: • brake caliper • brake caliper mounting bolts Brake caliper mounting bolt 35 Nm (3.5 m •...

  • Page 180: Rear Brake Master Cylinder

    CHAS REAR BRAKE EBS00407 REAR BRAKE MASTER CYLINDER 14 Nm (1.4 m•kg, 10.1 ft•lb) 12 Nm (1.2 m•kg, 8.7 ft•lb) 28 Nm (2.8 m•kg, 20.3 ft•lb) Order Job/Part Q’ty Remarks Removing the rear brake master Remove the parts in the order listed. cylinder Brake fluid Drain.

  • Page 181: Checking The Master Cylinder

    CHAS REAR BRAKE EBS00413 CHECKING THE MASTER CYLINDER 1. Check: • brake master cylinder Wear/scratches → Replace the brake mas- ter cylinder assembly. • brake master cylinder body Cracks/damage → Replace. • brake fluid delivery passage (brake master cylinder body) Blockage →...

  • Page 182: Installing The Rear Brake Master Cylinder

    CHAS REAR BRAKE EBS00418 INSTALLING THE REAR BRAKE MASTER CYLINDER 1. Install: • brake master cylinder Brake master cylinder holder bolt 14 Nm (1.4 m•kg, 10.1 ft•lb) • The “UP” mark on the brake master cylinder bracket should face up. •...
  • Page 183 CHAS REAR BRAKE 3. Fill: • brake fluid reservoir Recommended brake fluid DOT 4 NOTICE Brake fluid may damage painted surfaces or plastic parts. Always clean up spilled brake fluid immediately. WARNING • Use only the designated quality brake fluid: other brake fluids may deteriorate the rubber seals, causing leakage and poor brake performance.

  • Page 184: Rear Brake Caliper

    CHAS REAR BRAKE REAR BRAKE CALIPER 35 Nm (3.5 m kg, 25.3 ft • • 28 Nm (2.8 m kg, 20.3 ft • • Order Job/Part Q’ty Remarks Remove the parts in the order listed. Removing the rear brake caliper Brake fluid Drain.
  • Page 185 CHAS REAR BRAKE 16 Nm (1.6 m kg, 11.6 ft • • 8 Nm (0.8 m kg, 6.5 ft • • 25 Nm (2.5 m kg, 18.1 ft • • Order Job/Part Q’ty Remarks Remove the parts in the order listed. Disassembling the rear brake cali- Adjusting bolt Locknut...

  • Page 186: Removing The Parking Brake Cable

    CHAS REAR BRAKE REMOVING THE PARKING BRAKE CABLE 1. Loosen: • nut • adjusting bolt 2. Disconnect: • parking brake cable (from parking brake lever) 3. Disconnect: • parking brake cable (from rear brake) CHECKING THE REAR BRAKE CALIPER Recommended brake component replacement schedule Brake pads As required...

  • Page 187: Installing The Rear Brake Caliper

    CHAS REAR BRAKE EBS00436 INSTALLING THE REAR BRAKE CALIPER 1. Install: • brake caliper assembly • brake caliper mounting bolts Brake caliper mounting bolt 35 Nm (3.5 m•kg, 25.3 ft•lb) • brake hose • copper washers • union bolt Union bolt 28 Nm (2.8 m•kg, 20.3 ft•lb) NOTICE When installing the brake hose on the...
  • Page 188 CHAS REAR BRAKE WARNING • Use only the designated quality brake fluid: other brake fluids may deteriorate the rubber seals, causing leakage and poor brake performance. • Refill with the same type of brake fluid: mixing brake fluids may result in a harm- ful chemical reaction and lead to poor brake performance.

  • Page 189: Steering System

    CHAS STEERING SYSTEM EBS00444 STEERING SYSTEM HANDLEBAR 14 Nm (1.4 m kg, 10.1 ft • • 14 Nm (1.4 m kg, 10.1 ft • • 14 Nm (1.4 m kg, 10.1 ft • • Order Job/Part Q’ty Remarks Removing the handlebar Remove the parts in the order listed.
  • Page 190 CHAS STEERING SYSTEM 14 Nm (1.4 m kg, 10.1 ft • • 14 Nm (1.4 m kg, 10.1 ft • • 14 Nm (1.4 m kg, 10.1 ft • • Order Job/Part Q’ty Remarks Parking brake lever Refer to “INSTALLING THE PARKING BRAKE LEVER”.

  • Page 191: Removing The Handlebar Grips

    CHAS STEERING SYSTEM EBS00447 REMOVING THE HANDLEBAR GRIPS 1. Remove: • handlebar grips Blow compressed air between the handlebar and handlebar grip, and gradually push the grip off the handlebar. EBS00445 REMOVING THE REAR BRAKE SWITCH 1. Remove: • rear brake switch Push the fastener when removing the rear brake switch out of the rear brake lever holder.

  • Page 192: Installing The Handlebar

    CHAS STEERING SYSTEM EBS00449 INSTALLING THE HANDLEBAR 1. Install: • handlebar • upper handlebar holders 14 Nm (1.4 m · kg, 10.1 ft · lb) • Install the handlebar, please align the punch mark the gap at handlebar holder • The upper handlebar holders should be installed with the flange forward NOTICE...

  • Page 193: Installing The Rear Brake Master Cylinder

    CHAS STEERING SYSTEM EBS00451 INSTALLING THE REAR BRAKE MASTER CYLINDER 1. Install: • handlebar switch • handlebar grip • brake master cylinder • Installing the rear brake master cylinder, make sure the handlebar switch , handlebar grip , and brake master cylinder are in the positions shown in the illustration.

  • Page 194: Installing The Parking Brake Lever

    CHAS STEERING SYSTEM INSTALLING THE PARKING BRAKE LEVER 1. Install: • parking brake lever • parking brake cable • damper • parking brake lever plate • parking brake lever bracket Align the holder plate on the handlebar with align position of the parking brake lever.

  • Page 195: Steering Stem

    CHAS STEERING SYSTEM EBS00454 STEERING STEM 25 Nm (2.5 m kg, 18.1 ft • • 35 Nm (3.5 m kg, 25.3 ft • • 35 Nm (3.5 m kg, 25.3 ft • • 55 Nm (5.5 m kg, 39.8 ft •...

  • Page 196: Checking The Steering Stem

    CHAS STEERING SYSTEM EBS00455 REMOVING THE STEERING STEM 1. Remove: • steering stem When loosening each tie-rod end nut , hold the tie-rod ball joint with a 14-mm wrench EBS00456 CHECKING THE STEERING STEM 1. Check: • steering stem Bends → Replace. WARNING Do not attempt to straighten a bent stem;...

  • Page 197: Installing The Lower Handlebar Holder

    CHAS STEERING SYSTEM INSTALLING THE LOWER HANDLEBAR HOLDER 1. Install: • lower handlebar holder • nuts 35 Nm (3.5 m • kg, 25.3 ft • Ib) The lower handlebar holder and steering stem should be set a right angle when assembling. INSTALLING THE STEERING STEM 1.

  • Page 198: Tie-Rods And Steering Knuckles

    CHAS STEERING SYSTEM EBS00460 TIE-RODS AND STEERING KNUCKLES 35 Nm (3.5 m • kg, 25.3 ft • Ib) 18 Nm (1.8 m • kg, 13.0 ft • Ib) 35 Nm (3.5 m • kg, 25.3 ft • Ib) 25 Nm (2.5 m • kg, 18.1 ft • Ib) 35 Nm (3.5 m •...

  • Page 199: Removing The Steering Knuckles

    CHAS STEERING SYSTEM EBS00461 REMOVING THE TIE-RODS The following procedure applies to both of the tie-rods. 1. Remove: • tie-rod When removing the tie-rod, hold each tie-rod ball joint with a 14-mm wrench and then loosen the tie-rod end nut. EBS00461 REMOVING THE STEERING KNUCKLES The following procedure applies to both of the...

  • Page 200: Installing The Tie-Rods

    CHAS STEERING SYSTEM EBS00465 INSTALLING THE TIE-RODS The following procedure applies to both of the tie-rods. 1. Install: • tie-rod 35 Nm (3.5 m · kg, 25.3 ft · lb) • The tie-rod side which must be installed on outside has grooves •...

  • Page 201: Front Arms And Front Shock Absorber Assemblies

    FRONT ARMS AND FRONT SHOCK ABSORBER CHAS ASSEMBLIES EBS00460 FRONT ARMS AND FRONT SHOCK ABSORBER ASSEMBLIES 35 Nm (3.5 m • kg, 25.3 ft • Ib) 35 Nm (3.5 m • kg, 25.3 ft • Ib) 18 Nm (1.8 m • kg, 13.0 ft • Ib) 35 Nm (3.5 m •...

  • Page 202: Removing The Front Arms

    FRONT ARMS AND FRONT SHOCK ABSORBER CHAS ASSEMBLIES EBS00469 REMOVING THE FRONT ARMS 1. Check: • front arm free play a. Check the front arm side play by moving it from side to side. If side play is noticeable, check the bush- ings.

  • Page 203: Checking The Ball Joints

    FRONT ARMS AND FRONT SHOCK ABSORBER CHAS ASSEMBLIES EBS00472 CHECKING THE BALL JOINTS The following procedure applies to both of the front arm ball joints. 1. Check: • ball joint Damage/pitting → Replace the front arm. Free play → Replace the front arm. Turns roughly →...

  • Page 204: Rear Shock Absorber, Swingarm And Drive Chain

    REAR SHOCK ABSORBER, SWINGARM AND CHAS DRIVE CHAIN REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN 35 Nm (3.5 m • kg, 25.3 ft • Ib) 10 Nm (1.0 m • kg, 7.2 ft • Ib) 75 Nm (7.5 m • kg, 54.2 ft • Ib) 18 Nm (1.8 m •...

  • Page 205: Drive Chain

    REAR SHOCK ABSORBER, SWINGARM AND CHAS DRIVE CHAIN 35 Nm (3.5 m • kg, 25.3 ft • Ib) 10 Nm (1.0 m • kg, 7.2 ft • Ib) 75 Nm (7.5 m • kg, 54.2 ft • Ib) 18 Nm (1.8 m • kg, 13.0 ft • Ib) 35 Nm (3.5 m •...

  • Page 206: Removing The Rear Shock Absorber

    REAR SHOCK ABSORBER, SWINGARM AND CHAS DRIVE CHAIN EBS00487 REMOVING THE REAR SHOCK ABSORBER 1. Remove: • rear shock absorber lower bolt • rear shock absorber upper bolt While removing the rear shock absorber lower bolt, hold the swingarm so that it does not drop down.

  • Page 207: Checking The Swingarm

    REAR SHOCK ABSORBER, SWINGARM AND CHAS DRIVE CHAIN c. Check the swingarm vertical movement by moving it up and down. If vertical movement is tight or rough, or if there is binding, check the spacer, bearings and frame pivot. 2. Remove: •...

  • Page 208: Checking The Drive Chain

    REAR SHOCK ABSORBER, SWINGARM AND CHAS DRIVE CHAIN EBS00496 CHECKING THE DRIVE CHAIN 1. Measure: • 15-link section of the drive chain Out of specification → Replace the drive chain. 15-link drive chain section limit (maximum) 239.3 mm (9.42 in) •...

  • Page 209: Installing The Drive Sprocket

    REAR SHOCK ABSORBER, SWINGARM AND CHAS DRIVE CHAIN 4. Check: • drive chain rollers Damage/wear → Replace the drive chain. • drive chain side plates Cracks/damage/wear → Replace the drive chain. 5. Lubricate: • drive chain 6. Check: • drive sprocket •...

  • Page 210: Electrical Components

    ELEC – ELECTRICAL COMPONENTS EBS00500 ELECTRICAL ELECTRICAL COMPONENTS Main switch Battery Thermo switch Rectifier/regulator Ignition coil Main fuse Pickup coil/stator assembly Carburetor warmer Starter motor Rear brake switch C.D.I. unit Handlebar switch Starter relay Wire harness 7 - 1...

  • Page 211: Checking Switch Continuity

    ELEC – CHECKING SWITCH CONTINUITY EBS01028 CHECKING SWITCH CONTINUITY Check each switch for continuity with the pocket tester. If the continuity reading is incor- rect, check the wiring connections and if nec- essary, replace the switch. NOTICE Never insert the tester probes into the cou- pler terminal slots .

  • Page 212: Checking The Switches

    ELEC – CHECKING THE SWITCHES EBS01029 CHECKING THE SWITCHES Check each switch for damage or wear, proper connections, and also for continuity between the ter- minals. Refer to “CHECKING SWITCH CONTINUITY”. → Damage/wear Repair or replace. → Improperly connected Properly connect. →...

  • Page 213: Ignition System

    ELEC – IGNITION SYSTEM EBS00503 IGNITION SYSTEM CIRCUIT DIAGRAM B W/B W B/R B/R B/G B Y/B L /W Y/B B L /W L /W B/W B/W C.D.I. magneto Main switch C.D.I. unit Ignition coil Spark plug Engine stop switch (handlebar) 7 - 4...

  • Page 214: Troubleshooting

    ELEC – IGNITION SYSTEM EBS01045 EBS01032 TROUBLESHOOTING 1. Spark plug The ignition system fails to operate (no • Check the condition of the spark plug. spark or intermittent spark). • Check the spark plug type. • Measure the spark plug gap. Check: Refer to “CHECKING THE SPARK PLUG”...
  • Page 215 ELEC – IGNITION SYSTEM EBS01034 EBS01036 2. Ignition spark gap 3. Spark plug cap resistance • Disconnect the spark plug cap from the • Remove the spark plug cap from the spark spark plug. plug lead. • Connect the pocket tester (“Ω × 1k” range) •...
  • Page 216 ELEC – IGNITION SYSTEM EBS01038 EBS01041 4. Ignition coil resistance 5. Main switch • Disconnect the ignition coil connectors • Check the main switch for continuity. from the ignition coil terminals. Refer to “CHECKING THE SWITCHES”. • Connect the pocket tester (Ω × 1) to the •...
  • Page 217 ELEC – IGNITION SYSTEM EBS01040 EBS01099 7. Pickup coil resistance 8. Source coil resistance • Disconnect the C.D.I. magneto coupler • Disconnect the C.D.I. magneto coupler from the wire harness. from the wire harness. Ω × Ω × • Connect the pocket tester ( 100) to the •...

  • Page 218: Electric Starting System

    ELEC – ELECTRIC STARTING SYSTEM EBS00506 ELECTRIC STARTING SYSTEM CIRCUIT DIAGRAM Main switch Main fuse Positive battery lead Battery Negative battery lead Starter relay Starter motor C.D.I. unit Rear brake switch Start switch B W/B W B/R B/R B/G Br B B Y/B L /W Y/B B...

  • Page 219: Starting Circuit Operation

    ELEC – ELECTRIC STARTING SYSTEM EBS00507 STARTING CIRCUIT OPERATION The starting circuit on this model consists of the starter motor, starter relay,rear brake switch. If the main switch is on and the engine stop switch is in the ON position, the starter motor can be operated only if: •...
  • Page 220 ELEC – ELECTRIC STARTING SYSTEM EBS01050 EBS01044 TROUBLESHOOTING 2. Battery The starter motor fails to turn. • Check the condition of the battery. Refer to “CHECKING AND CHARGING Check: THE BATTERY” in chapter 3. 1. main fuse 2. battery Minimum open-circuit voltage 3.
  • Page 221 ELEC – ELECTRIC STARTING SYSTEM EBS01054 EBS01046 4. Starter relay 6. Rear brake switch • Disconnect the starter relay coupler from • Check the rear brake switch for continuity. the coupler. Refer to “CHECKING THE SWITCHES”. • Connect the pocket tester (Ω × 1) and bat- •...
  • Page 222 ELEC – STARTER MOTOR EBS01061 STARTER MOTOR 12Nm (1.2m．kg, 8.7ft．lb) 12Nm (1.2m．kg, 8.7ft．lb) Order Job/Part Q’ty Remarks Removing the starter motor Remove the parts in the order listed. Starter motor lead Ground lead Starter motor For installation, reverse the removal pro- cedure.

  • Page 223: Checking The Starter Motor

    ELEC – STARTER MOTOR EBS01064 CHECKING THE STARTER MOTOR 1. Check: • commutator Dirt → Clean with 600-grit sandpaper. 2. Measure: • commutator diameter Out of specification → Replace the starter motor. Commutator wear limit 19.5 mm (0.77 in) 3. Measure: •...

  • Page 224: Assembling The Starter Motor

    ELEC – STARTER MOTOR 5. Measure: • brush length Out of specification → Replace the brushes as a set. Brush length wear limit 3.5 mm (0.14 in) 6. Measure: • brush spring force Out of specification → Replace the brush springs as a set.

  • Page 225: Charging System

    ELEC – CHARGING SYSTEM EBS00516 CHARGING SYSTEM CIRCUIT DIAGRAM B W/B W B/R B/R B/G B Y/B L /W Y/B B L /W L /W B/W B/W C.D.I. magneto Rectifier/regulator Main fuse Positive battery lead Battery Negative battery lead 7 - 16...
  • Page 226 ELEC – CHARGING SYSTEM EBS01065 EBS01043 TROUBLESHOOTING 1. Main fuse The battery is not being charged. • Check the main fuse for continuity. Refer to “CHECKING THE FUSE” in chap- Check: ter 3. 1. main fuse • Is the main fuse OK? 2.
  • Page 227 ELEC – CHARGING SYSTEM EBS01066 EBS01100 3. Charging voltage 4. Charging coil resistance • Connect the engine tachometer to the • Disconnect the C.D.I. magneto coupler spark plug lead. from the wire harness. • Connect the pocket tester (Ω × 1) to the •...

  • Page 228: Troubleshooting

    TRBL STARTING FAILURE/HARD STARTING SHTG EBS00537 TROUBLESHOOTING The following troubleshooting does not cover all the possible causes of trouble. It should be helpful, however, as a guide to troubleshooting. Refer to the relative procedure in this manual for check, adjustment and replacement of parts. STARTING FAILURE/HARD STARTING FUEL SYSTEM ELECTRICAL SYSTEM...

  • Page 229: Compression System

    TRBL STARTING FAILURE/HARD STARTING/POOR IDLE SPEED SHTG PERFORMANCE/POOR MEDIUM AND HIGH-SPEED PERFORMANCE COMPRESSION SYSTEM Cylinder and cylinder head Piston and piston rings • Loose spark plug • Improperly installed piston ring • Loose cylinder head or cylinder • Worn, fatigued or broken piston ring •...

  • Page 230: Faulty Clutch

    FAULTY GEAR SHIFTING/CLUTCH SLIPPING/ TRBL DRAGGING/OVERHEATING SHTG EAS00853 FAULTY CLUTCH ENGINE OPERATES BUT VEHICLE WILL POOR STARTING PERFORMANCE NOT MOVE V-belt • V-belt slips V-belt • Oil or grease on the V-belt • Bent, damaged or worn V-belt Primary sliding sheave •...

  • Page 231: Faulty Brake

    FAULTY BRAKE/SHOCK ABSORBER MALFUNCTION/ TRBL UNSTABLE HANDLING SHTG EBS00549 FAULTY BRAKE POOR BRAKING EFFECT Front drum brake Rear disc brake • Worn brake shoe lining • Worn brake pads • Worn brake drum • Worn disc • Oily or greasy brake shoe lining •...
  • Page 234 YAMAHA MOTOR CO., LTD. 2500 SHINGAI IWATA SHIZUOKA JAPAN PRINTED IN U.S.A.
  • Page 235 YFM90R WIRING DIAGRAM B W/B C.D.I. magneto Main switch Rectifier/regulator Main fuse Positive battery lead Battery W B/R B/R B/G Negative battery lead Starter relay Starter motor C.D.I. unit Ignition coil Spark plug Rear brake switch Handlebar switch Start switch Engine stop switch (handlebar) Thermo switch Carburetor warmer...

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