Yamaha YFM90RA manual

SERVICE MANUAL YFM90R A 43D-F8197-1 2 LIT-11616-2 4 -1 6 201 1[...]

EBS00001 YFM90R A SERVICE MANUAL ©20 10 by Yamaha Motor Corporation, U.S.A. First edition, July 20 10 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-11616-2 4 -1 6[...]

EBS00002 IMPORTANT This manual was produced b y the Y amaha Motor Company primarily f or use by Y amaha dealers and their qualified mechanics. It is not possib le to in clude 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 Y amaha machine has a basic understandin[...]

EBS00004 HOW TO USE THIS MANUAL MANUAL ORGANIZATION This manual consists of chapters for the main categories of subje cts. (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 secti on of the chapter a nd only appears on the first page of e ach [...]

EBS00005 SYMBOLS The following symbols are not relevant to every machine. Symbols to indicate the subject of each chapter. General information Specifications Periodic checks and adjustmen ts Engine Carburetor Chassis Electrical Troubleshooting Symbols to indicate the following. Serviceable with en gine mounted Filling fluid Lubricant Special tool T[...]

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EBS00007 TABLE OF CONTENTS GENERAL INFORMATION GEN INFO 1 SPECIFICATIONS SPEC 2 PERIODIC CHECKS AND ADJUSTMENTS CHK ADJ 3 CARBURETOR CARB 5 ENGINE ENG 4 CHASSIS CHAS 6 ELECTRICAL ELEC – + 7 TROUBLESHOOTING TRBL SHTG 8[...]

CONTENTS CHAPTER 1 GENERAL INFORMATION MACHINE IDENTIFICATION ........................................................................... 1-1 VEHICLE IDENTIFICATION NUMBER ..................................................... 1-1 MODEL LABEL ............................................ .............................................. 1-1 IMPORTANT IN[...]

OIL FLOW DIAGRAMS ................................................................................. 2-21 CABLE ROUTING ......................................................................................... 2-22 CHAPTER 3 PERIODIC CHECKS AND ADJUSTMENTS INTRODUCTION .......................................................... ......................[...]

ELECTRICAL SYSTEM ................................................................................. 3-37 CHECKING AND CHARGING THE BATTERY ....................................... 3-37 CHECKING THE FUSES .........................................................................3-44 CHAPTER 4 ENGINE ENGINE .............................................[...]

BELT DRIVE .............................................................................................. .. 4-31 CRANKCASE COVER.................................................... ................... ...... 4-31 KICKSTARTER........................................................................ ................ 4-32 INSTALLING THE KICKSTARTER....[...]

CHAPTER 5 CARBURETOR CARBURETOR ................................................................................................ 5-1 DISASSEMBLING THE CARBURETOR ................................................... 5-4 CHECKING THE CARBURETOR ............................................................. 5-4 ASSEMBLING THE CARBURETOR ................[...]

STEERING SYSTEM ..................................................................................... 6-28 HANDLEBAR ........................................................................................... 6-28 REMOVING THE HANDLEBAR GRIPS .................................................. 6-30 REMOVING THE REAR BRAKE SWITCH ....................[...]

CHAPTER 7 ELECTRICAL ELECTRICAL COMPONENTS ........................................................................ 7-1 CHECKING SWITCH CONTINUITY ................................................................ 7-2 CHECKING THE SWITCHES ...................................................................... .... 7-3 IGNITION SYSTEM ................[...]

CHAPTER 8 TROUBLESHOOTING STARTING FAILURE/HARD STARTING ................................................... .... 8-1 FUEL SYSTEM.......................................................................................... 8-1 ELECTRICAL SYSTEM ............................................................................. 8-1 COMPRESSION SYSTEM .......[...]

GEN INFO EBS00009 GENERAL INFORMA TION MA CHINE IDENTIFICA TION EBS00010 VEHICLE IDENTIFICA TION NUMBER The ve hicl e i den tifi cati on numb er is sta mped into the left side of the frame . EBS00011 MODEL LABEL The model label is affixed to the frame. This in form atio n wi ll be n eede d to ord er sp are parts . MA CH INE IDENTIFICA TION 1 - 1[...]

1 - 2 GEN INFO IMPORTANT INFORMATION EBS00013 IMPORTANT INFORMATION PREPARATION FOR REMOVAL AND DISASSEMBLY 1. Bef ore removal and disassembly remov e all dir t, mud, dust and f oreign mater ial. 2. Use only the proper tools and cleaning equipment. Refer to “SPECIAL TOOLS”. 3. When disassembling alwa ys k eep mated par ts together . This includ[...]

1 - 3 GEN INFO IMPORTANT INFORMATION 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 t he manu- facturer’[...]

1 - 4 GEN INFO IMPORTANT INFORMATION EBS00019 CHECKING THE CONNECTIONS Check the leads, couplers, and connectors for stains, rust, moisture, etc. 1. Disc onnect: • lead • coupler • connector 2. Check: • lead • coupler • connector Moisture → Dry with an air b lower. Rust/stains → Connect and disconnect sev- eral times. 3. Check: • [...]

1 - 5 GEN INFO SPECIAL TOOLS 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 count[...]

1 - 6 GEN INFO SPECIAL TOOLS Gauge 90890-03081 YU-33223 Adapter 90890-04082 Compression gauge Adapter These tools are needed to meas ure engine compression. 90890-03112 YU-03112-C YU-8036-B Pocket tester This instrument is needed for c hecking the electrical system. 90890-03113 Engine tachometer This tool is needed for observing engine rpm. 90890-0[...]

1 - 7 GEN INFO SPECIAL TOOLS YM-34487 Dynamic spark tester This instrument is necessary for checking the ignition system components. 9 0 8 9 0 - 01 3 8 4 YM -3 3 29 9 Oil seal guide Thi s to ol is used for prote ctin g t he o il seal lip when installing the secondary sliding sheave. 9 0 8 9 0 - 01 3 4 8 YM -0 1 34 8 Lock nut wrench This tool is use[...]

2 - 1 SPEC EBS01001 SPECIFICATIONS GENERAL SPECIFICATIONS Item Standard Model code 43D 7 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 2,900 mm (114in) Basic weight W[...]

2 - 2 SPEC Item Standard Fuel T ype 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 T ype / quantity SVR 22-1G x 1 Manuf acturer TK Spark plug T ype / manufacturer NGK/CR7HSA Spark plug gap 0.6 ~ 0.7 mm (0.024 ~ 0.028 in) Clutch type Dry, centrifugal automa[...]

SPEC Item Standard Brake F ront brake type Drum brake operation Right hand operation Rear brak e type Single disc brak e operation Left hand operation Suspension F ront suspension Double wishbone / Independent Rear suspension Swingarm Shock absorber F ront shock absorber Coil spring / oil damper Rear shock absorber Coil spring / oil damper Wheel tr[...]

2 - 4 SPEC ENGINE SPECIFICATIONS EBS01002 ENGINE SPECIFICATIONS Item Standard Limit Cylinder head Warp limit 0.05 mm (0.002 in) Cylinder Bore size 47.000 ~ 4 7.010 mm (1.8504 ~ 1.8508 in) 7.00 ~ 7.40 cm 3 (0.43 ~ 0.45 cu.in) 47.10 mm (1.8543 in) Taper limit ---- 0.05 mm (0.002 in) Maximum out-of-round ---- 0.01 mm (0.0004 in) Camshaft Drive method [...]

SPEC ENGINE SPECIFICATIONS Rocker arm/rocker arm shaft Rocker arm inside diameter 10.000 ~ 10.015 mm (0.3937 ~ 0.3943 in) Rocker arm shaft outside diameter 9.972 ~ 9.987 mm (0.3926 ~ 0.3932 in) Rocker-arm-to-rocker-arm-shaft clearance 0.013 ~ 0.043 mm (0.0005 ~ 0.0017 in) Valve, valve seat, valve guide Valve clearance (col d) IN 0.07 ~ 0.10 mm (0.0[...]

2 - 6 SPEC ENGINE SPECIFICATIONS Stem-to-guide clearance IN 0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in) 0.08 mm (0.0031 in) EX 0.025 ~ 0.052 mm (0.0010 ~ 0.0020 in) 0.10 mm (0.0039 in) Stem runout limit ---- 0.02 mm (0.0008 in) Valve seat width IN 0.8 ~ 1.1 mm (0.0315 ~ 0.0433 in) 1.6 mm (0.0630 in) EX 0.8 ~ 1.1 mm (0.0315 ~ 0.0433 in) 1.6 mm (0.0630 in)[...]

2 - 7 SPEC ENGINE SPECIFICATIONS 0.10 mm (0.0039 in) (0.0004 ~ 0.0016 in) 46.970 ~ 46.990 mm (1.8492 ~ 1.8500 in) (0.5119 ~ 0.5121 in) 13.040 mm (0.5134 in) (0.5117 ~ 0.5118 in) 12.960 mm (0.5102 in) Limit Standard Item Piston Piston to cylinder clearance 0.010 ~ 0.040 mm Piston size “D” Measuring point “H” ---- 0.5 mm (0.02 in) 5.0 mm (0.2[...]

SPEC ENGINE SPECIFICATIONS ---- Barrel 1.0 × 2.1 mm (0.0394 × 0.0827 in) ---- 0.10 ~ 0 .25 mm (0.0039~0.0098in) 0.4 5 mm (0.0177in) 0.015 ~0.055 mm (0.0006~0.0022in) 0.0 9 mm (0.0035in) ---- Taper 1.0 × 2.0 mm 0.0394 × 0.0787 in) ---- 0.25 ~ 0 .40 mm (0.0098~0.0157in) 0.55mm (0.0217in) 0.015 ~ 0.055 mm (0.0006~0.0022in) 0.09mm (0.0035in) 2.0 ×[...]

SPEC ENGINE SPECIFICATIONS Automatic centrifugal Clutch type 4.0 mm Clutch shoe thickness Clutch shoe spring free length Clutch housing inside diameter Compression spring free length 87.9 mm (3.46 in) Weight outside diameter 2110±140r/min Clutch-in revolution 2350±150 r/min Clutch-stall revolution ---- ---- ---- V-belt width Clutch V-belt (0.1575[...]

2 - 10 SPEC ENGINE SPECIFICATIONS Oil pump ---- Trochoid Oil pump type Inner-rotor-to-outer-rotor-tip clearance (0.0016 ~ 0.0047 in) 0.15 mm (0.006 in) Outer-rotor-to-oil-pump-housing clearance (0.0055 ~ 0.0083 in) 0.28 mm (0.0110 in) Oil-pump-housing-to-inner-rotor-and-outer- rotor clearance 0.06 ~ 0.11 mm 0.14 ~ 0.21 mm 0.04 ~ 0.12mm (0.0024 ~ 0.[...]

SPEC CHASSIS SPECIFICATIONS EBS01003 CHASSIS SPECIFICATIONS Item Standard Limit Front suspension Shock absorber travel 35 mm (1.38 in) ---- Optional spring No ---- Rear suspension Shock absorber travel 40 mm (1.57 in) ---- Optional spring No ---- Front wheel Type Panel wheel ---- Rim size 8 × 5.5 AT ---- Rim material Steel ---- Rim runout limit ra[...]

2 - 12 SPEC CHASSIS SPECIFICATIONS Item Standard Limit Brake lever Brake lever free play (pivot) front 4.0 ~ 6.0 mm (0.16 ~ 0.24 in) ---- rear 0 ~ 1.5 mm (0 ~ 0.06 in) ---- Throttle lever free play 1.0 ~ 3.0 mm (0.04 ~ 0.12 in) ---- Rear disc brake Type Disc outside diameter × thickness 3.0 mm (0.12 in) Brake disk maxim um deflection 0.15 mm (0.00[...]

2 - 13 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-A26-600 0/SHIHLIN ---- Pickup coil resista[...]

2 - 14 SPEC ELECTRICAL SPECIFICATIONS Electric starter system ---- Constant mesh Type Starter motor ---- C1200-A26-6000/SY Model/manufacturer ---- ---- 0.35 kW Output Armature coil resistance 0.014 ~ 0.019 at 20 °C (68 ° ---- F) 3.5 mm 7.0 mm (0.28 in) 1.0 ~ 3.0 N Brush overall length (0.14 in) Spring force (102~ 306gf, 3.60 ~ 10.80 oz) ---- 19.5[...]

2 - 15 SPEC TIGHTENING TORQUES EBS01005 TIGHTENING TORQUES ENGINE TIGHTENING TORQUES Part to be tightened Part name Thread size Q’ty Tightening torque Remarks Nm m · kg ft · lb Cylinder head (exhaust pipe) Stud bolt M6 2 9 0.9 6.5 Cylinder head (Carb. joint) Stud bolt Cover head cylinder M6 4 12 1.2 8.7 M6 2 12 1.2 8.7 M6 1 1 0.1 0.7 1 1 5 . 1 [...]

2 - 16 SPEC TIGHTENING TORQUES EBS01006 CHASSIS TIGHTENING TORQUES Part to be tightened Thread size Tightening torque Nm m · kg ft · lb M10 Rear shock absorber and frame M10 Rear shock absorber and swingarm M10 Front shock absorber and frame M10 Steering stem and frame M14 Steering stem and tie-rod ball joint M10 Tie-rod locknut M10 Steering knuc[...]

2 - 17 SPEC TIGHTENING TORQUES 1. Bef ore tightening the nuts, apply loc king 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 1 70 Nm (17.0 m · kg, 123 ft · lb) while holding the inside n ut. TIP[...]

2 - 18 SPEC HOW TO USE THE CONVERSION TABLE/ GENERAL TIGHTENING TORQUE SPECIFICATIONS EBS00022 HOW TO USE THE CONVERSION TABLE All specification data in this manual are listed in SI and METRIC UNITS. Use this table to convert METRIC unit data to IMPERIAL unit data. CONVERSION TABLE EBS00023 GENERAL TIGHTENING TORQUE SPECIFICATIONS This chart specif[...]

SPEC Lubrication P oint Lubr icant LS LS E M LS E LS LS E E E E E E E M M M E E E LS LS LUBRICA TION POINTS AN D LUBRIC ANT TYPES Oil seal lips O-ring (Except V -belt drive unit) Cylinder head tightening nut mounting surf ace Cylinder head stud bolt thread Cylinder head gasket dowel pin Crankshaft pin outside surf ace Connecting rod Piston outside [...]

SPEC BEL-RA Y asembly lube BEL-RA Y asembly lube Sealant Sealant Sealant Sealant Sealant Lubrication P oint Lubricant LUBRICA TION POINTS AND LUBRICANT TYPES LS Primar y sheav e inside, Collar , Solid bush, Secondary fixed inner surface Secondar y sheav e torque cam ditch Gasket (Cylinder head cov er) Stopper guide (Cylinder head cover) Crankcase m[...]

2 - 21 SPEC OIL FLOW DIAGRAMS EBS00026 OIL FLOW DIAGRAMS Camshaft Crankshaft Oil pump Oil filter 1 2 3 4[...]

2 - 22 SPEC CABLE ROUTING EBS00028 CABLE ROUTING Rear brake hose Parki ng brake cable Throttle cable Carburetor air vent hose Final gear case breather hose Fuel overflow hose Front brake cables Fuel hose Choke cab le Air filter case check hose Fuel tank breather hose Oil catch hose Wire harness Handlebar switch lead Rear brake switch lead 0 A B C C[...]

2 - 23 SPEC CABLE ROUTING EBS00028 A P ass the front brake cab les, parking brake cab le, throttle cable and chok e cable through the hose guide . B F asten the choke cab le, handlebar s witch lead and rear brak e switch lead with a plastic band. Inser t the fuel tank breather hose into the hole in the handlebar cover . C E F D Inser t the final ge[...]

2 - 24 SPEC CABLE ROUTING Fas te n t he fu el ove rfl ow ho se an d c ar bur eto r air ve nt ho se wi th a met al ba nd. Be s ure t o n ot pi nch t he hos e. H F asten the fuel drain hose with a metal band. Be sure to not pinch the hose. I Fasten the rear brake hose and choke cable with a plastic band. J P ass the rear brake hose through the hose g[...]

2 - 25 SPEC CABLE ROUTING Wire harness 0 Fuel drain hose Rear brak e hose Throttle cable P ar ki n g br ake cab le F ront brake cab les Air filter case check hose A P ositive star ter motor lead B P ositive batter y lead C Negative battery lead D Star ter motor E Generator lead F G Main s witch H The rmo sw itch I Ignition coil J Rectifier/regulato[...]

2 - 26 SPEC CABLE ROUTING A P ass these leads through rear f ender . B Fasten the wire harness, main switch lead, thermo switch lead and with a plastic band. C Fasten the wire harness and generator lead with a plastic band. D Fasten the wire harness, negative battery lead and starter motor lead with a plastic band. E F asten the wire har ness, posi[...]

2 - 27 SPEC CABLE ROUTING P ass the positive battery lead through the hose guide. P ass the negative battery lead through the hose guide. P ass the positive battery lead, positive starter motor lead and wire har ness through the hose guide. P ass the positive battery lead, positive starter motor lead and star ter rela y lead through the hose guide.[...]

2 - 28 SPEC CABLE ROUTING Rear brake switch lead Rear brake hose Front brake cable (right) Front brake cable (left) 1 2 3 4 Throttle cable 5 Parking brake cable 6 Handlebar switch Negative battery lead 12 11 Fuel tank breather hose Positive battery lead 7 Battery 8 9 10 Main fuse 1 2 3 4 6 7 8 9 11 13 12 A 10 A B C D E F G A 5 Choke cable 13[...]

2 - 29 SPEC CABLE ROUTING Connect the negative battery lead to the battery so that the lead is routed to the side of the battery. Connect the positive battery lead to the battery so that the l ead contacts the battery case. Fasten the handlebar switch lead , rear brake switch lead and choke cable with a plastic band. Face the opening of the positi [...]

SPEC CABLE ROUTING 2 - 30 Rear brake hose Crankcase breather hose Oil catch hose Choke cable Rear brake switch lead Handlebar switch lea d Throttle cable 1 2 3 4 5 6 7 Fasten the handlebar switch l ead , rear brake switch lead and choke cab le with a plastic band. A Front brake cable (left) Parking brake cable 8 Front brake cable (right) 10 9 A Ign[...]

3 - 1 CHK ADJ EBS00029 PERIODIC CHECKS AND ADJUSTMENTS INTRODUCTION This chapter includes all information necessary to perform recommended checks and adjustments . These preventive maintenance procedures, if followed, wi ll ensure more reliable machine operation and a longer service life. The need for costly overhaul work will be greatly reduced. T[...]

3 - 2 CHK ADJ INTRODUCTION/ PERIODIC MAINTENANCE/LUBRICATION 11 * Shock absorber assemblies Check operation and correct if necessary . Che c k f or o il lea kage an d rep lac e if ne ces sary . 12 * Front knuckle piv- ots Lubricate with lithium-soap-based grease. 13 * Steering shaft Lubricate with lithium-soap-based grease. 14 * Steering system Che[...]

3 - 3 CHK ADJ 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. 1 Seat 1 TIP Pull back the s eat lock lever, than pull up on the rear of the seat. 2 Front panel 1 3 Fuel tank breather hose 1 4 Handlebar cover 1 T[...]

3 - 4 CHK ADJ SEAT, FENDERS AND FUEL TANK EBS00037 FRONT FENDER 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”. 1 Fuel tank top panel 1 2 Air cleaner joint clamp screw 1 Loosen. 3 Main switch 1 4 Front fender 1 For installation, reverse the remov[...]

3 - 5 CHK ADJ SEAT, FENDERS AND FUEL TANK EBS00039 REAR FENDER AND FOOTREST BOARDS Order Job/Part Q’ty Remarks Removing the rear fender and foot- rest boards Remove the parts in the order listed. Seat Refer to “SEAT AND FRONT PANEL ”. Front fender Refer to “FRONT FENDER”. 1 Battery band 1 2 Wire harness and main fuse 1 3 Negative battery [...]

3 - 6 CHK ADJ Order Job/Part Q’ty Remarks 1 6 B at t e r y 2 7 Footrest board 1 8 Rear fender For installation, reverse the removal pro- cedure. SEAT, FENDERS AND FUEL TANK T R . . 9 Nm (0.9 m • kg, 6.5 ft • Ib) T R . . 9 Nm (0.9 m • kg, 6.5 ft • Ib) 1 2 3 4 5 6 T R . . 9 Nm (0.9 m • kg, 6.5 ft • Ib) T R . . 9 Nm (0.9 m • kg, 6.5 ft[...]

3 - 7 CHK ADJ SEAT, FENDERS AND FUEL TANK EBS00042 FUEL TANK Order Job/Part Q’ty Remarks Removing the fuel tank Remove t he parts in the order listed. Seat and front panel Refer to “SEAT AND FRONT PANEL”. Front fender Refer to “FRONT FENDER”. 1 Fuel hose 1 Disconnect. TIP Before disconnecting the fuel hose, turn the fuel cock to “OFF”[...]

3 - 8 CHK ADJ ADJUSTING THE VALVE CLEARANCE E A S 0 00 4 9 E N G I NE ADJUSTING THE V AL VE CLEARANCE The followin g proc edur e appl ies t o all of t he v alves . TIP V a l v e c le a ra n c e ad ju st me n t sh ou ld b e made on a cold engine , at room tempera- ture. When the valv e clearance is to be mea- sured or adjusted, the piston must be at[...]

3 - 9 CHK ADJ ADJUSTING THE VALVE CLEARANCE c. Measure the valv e clearance using a thic k- ness gauge . Out of specification Adjust 3. Adjust: • valve clearance a. Loosen the locknut . b . Inser t a thickness gauge between the adjuster end and the valv e end. c. T ur n the adjuster clockwise or counter- cloc kwise with the tappet adjusting tool [...]

CHK ADJ ADJUSTING THE ENGINE IDLING SPEED EBS00051 ADJUSTING THE ENGINE IDLING SPEED 1. Star t the engine and let it warm up for se v- eral minutes . 2. Attach: • engine tachometer (to the spark plug lead) 3. Measure: • engine idling speed Inductive self-powered tachome- ter P/N. YU-8036-B Engine tachometer P/N. 90890-03113 Engine idling speed [...]

3 - 11 CHK ADJ ADJUSTING THE THROTTLE LEVER FREE PLAY EBS00052 ADJUSTING THE THROTTLE LEVER FREE PLAY TIP _ 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. 2. Adjust: • throttle lever free play a. Pul l back the adjuster co v[...]

3 - 12 CHK ADJ 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. Measure: • speed limiter length Out of specification → A[...]

3 - 13 CHK ADJ CHECKING THE SPARK PLUG EBS00057 CHECKING THE SPARK PLUG 1. Remov e: • spark plug 2. Check: • spark plug type Incorrect → Change. 3. Check: • electrode Wear/damage → Replace. • insulator Abnormal color → Replace. Normal color is a medium-to-light tan color. 4. Clean: • spark plug (with a spark plug cleaner or wire bru[...]

3 - 14 CHK ADJ CHECKING THE IGNITION TIMING EBS00058 CHECKING THE IGNITION TIMING TIP Engine idling speed and throttle cable free play should be adjusted properly before checking the ignition timing. 1. Remov e: • Shroud cap 2. Attach: • engine tachometer • timing light (to spark plug lead) 3. Check: • ignition timing a. W ar m up the engin[...]

3 - 15 CHK ADJ MEASURING THE COMPRESSION PRESSURE EBS00061 MEASURING THE COMPRESSION PRESSURE TIP Insufficient compression pressure will result in a loss of performance. 1. Measure: • valve clearance Out of specification → Adjust. Refer to “ADJUSTING THE VALVE CLEARANCE”. 2. Star t the engine, w arm it up for se ver al min- utes, and then t[...]

3 - 16 CHK ADJ MEASURING THE COMPRESSION PRESSURE a. Set the main switch to “ON”. b . With the throttle w ide open, crank the engine until the reading on the compression gauge stabilizes . W ARNING _ To prevent sparking, ground the spark plug lead before cranking the engine. c. If the compression pressure is abov e the maximum specification, ch[...]

3 - 17 CHK ADJ CHECKING THE ENGINE OIL LEVEL EBS00064 CHECKING THE ENGINE OIL LEVEL 1. Place the machine on a le vel sur f ace. 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. TIP Do not screw the dipstick in when checking the oil level. a. W ar m up the en[...]

3 - 18 CHK ADJ 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. Remov e: • dipstick • engine oil drain bolt (along with the O-ring, spring and oil filter screen) 4. Drain: • engine oil (completely from [...]

CHK ADJ CLEANING THE AIR FILTER ELEMENT EBS00071 CLEANING THE AIR FILTER ELEMENTS TIP There is a check hose at the bottom of the air filter case. If dust and/or water collects in this hose, c lean t he air filter eleme nts and air f il- ter case. 1. Remov e: • air filter case covers 2. Loosen: • bolt 3. Remov e: • • • air filter element h[...]

3 - 20 CHK ADJ CLEANING THE AIR FILTER ELEMENT/ CLEANING THE SPARK ARRESTER b . Squeeze the excess solvent out of the spo- nge materials and let it dry. NOTICE D o no t t wi st o r wr i ng o ut th e sp o ng e ma t er ia l s. could damage the s po ng e ma te ri a ls . c. Appl y Yam ah a f oam a ir fi lte r o il or o the r qua li ty foam air filter o[...]

3 - 21 CHK ADJ c. T ap the tailpipe lightly with a soft-f ace ham- mer or suitable tool, then use a wire br ush to remo ve any carbon deposits from the spark arrester por tion of the tailpipe and the inner contact surf aces of the muffler . d. Insert the spark arrester into the muffler and align the screw holes . e. Inser t the bolt, nut and tighte[...]

3 - 22 CHK ADJ CHECKING THE FRONT BRAKE SHOES / ADJUSTING THE FRONT B RAKE CHASSIS EBS00082 ADJUSTING THE FRONT BRAKE TIP _ Before adjusting the front brake, the front brake linings should be checked. NOTICE _ Proper lever free play is essential to avoid excessive brake drag. 1. Measure: • front brake lever free play Out of specification → Adju[...]

3 - 23 ADJUSTING THE PARKING BRAKE CHK ADJ ADJUSTING THE P ARKING BRAKE 1. Check: • par king brake cab le end length Out of specification → Adjust. Parking brake cable end length 2. Adjust: • par king brake cab le end length a. Loosen the locknut and adjusting bolt . b. Loosen the lockn ut . c. T ur n the adjusting nut in direction or until t[...]

CHK ADJ 3 - 24 2. Check: • brake fluid le vel Below the minimum le vel mark → Add the recommended brak e fluid to the proper le vel. WARNING • Use only the designated brake fluid. Other brak e fluids may cause the rubber seals to deteriorate, causing leakage and poor brake performance. • Refill with the same type of brake fluid that is alre[...]

CHK ADJ 3 - 25 CHECKING THE REAR BRAKE PADS /CHECKING THE BRAKE HOSE/ BLEEDING THE HYDRAULIC BRAKE SYSTEM • rear brake hose Crac ks / wear / damage → Replace. 3. Check: • brake hose clamps Loosen → Tighten. 4. Hold the machine in an upright position and apply the rear brake . 5. Check: • brake hose Apply the brak e lev er times. Fluid lea[...]

CHK ADJ 3 - 26 TIP • Be careful not to spill any brake fluid or allow the brake master cylinder reser voir or brake fluid reser voir to o v erflow . • When bleeding the h ydraulic brake system, make sure there is always enough brake fluid bef ore apply ing the brake. Ignoring this pre- caution could allow air to enter the hydraulic brak e syste[...]

3 - 27 CHK ADJ CHANGING THE FINAL TRANSMISSION OIL / ADJUSTING THE DRIVE CHAIN SLA CK EBS00102 CHANGING T HE FINAL TRANSM ISSION OI L 1. Place the machine on a le vel sur face . 2. Pl a c e a re ce pt ac le u nd er th e fi n a l tr an sm is s i on case. 3. Remov e: • dipstick • final transmission oil drain plug 4. Drain: • final transmission [...]

1. Measure: • dr ive chain slac k Out of specification → Adjust. 2. Adjust: • dr ive chain slack TIP The dr ive chain slack is adjusted by the rota- tion of the rear axle hub . a. Loosen the rear axle pinch bolts . b . Loo sen the locknut . c. T o ti gh ten t he dri v e c ha in , turn t he d riv e ch ain a d j us ti ng n ut in di re ct io n .[...]

3 - 29 CHK ADJ CHECKING THE STEERING SYSTEM EBS00107 CHECKING THE STEERING SYSTEM 1. Place the machine on a le vel sur f ace. 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. Refer to “STEERING SYSTEM” in chapter 6. 3[...]

CHK ADJ 3 - 30 EBS00108 ADJUSTING THE T OE-IN 1. Place the machine on a lev el surf ace. 2. Measure: • toe-in Out of specification → Adjust. TIP Bef ore measuring the toe-in, make sure that the tire pressure is correct. a. Mark both front tire tread centers. b . F ace the handlebar straight ahead. c. Measure the width between the marks. d. Rota[...]

CHK ADJ 3 - 31 a. Mark both tie-rods ends. This ref erence 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. This is to keep the length of the rods the same. d. Tighten the rod end loc[...]

b b a EBS00111 ADJUSTING THE SHOCK ABSORBERS WARNING Always adjust the spring preload of both front shoc k absorbers to the same setting. Uneven adjustment can result in poor han- dling and loss of stability . 1. Adjust: • spr ing preload a. T ur n the adjusti ng ring in direction or with the spanner wrench . Direction Spring preload is increased[...]

3 - 33 CHK ADJ CHECKING THE TIRES EBS00114 CHECKING THE TIRES W ARNING _ This model is equipped with low pressure tires. It is important that they be inflated correctly and maintained at the proper pressures. • TIR E CHARACTERISTICS 1) Tire c haracteristics influence the han- dling of A TVs. The tires listed below have been approved by Y amaha Mo[...]

3 - 34 CHK ADJ CHECKING THE TIRES 1. Measure: • tire pressure Out of specification → Adjust. TIP _ • 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. W AR[...]

3 - 35 CHK ADJ CHECKING THE TIRES/ CHECKING THE WHEELS 2. Check: • tire surfaces Wear/damage → Replace. W ARNING _ It is dangerous to ride with a worn-out tire. When tire wear is out of specification, replace the tire immediately. Tire wear limit Front and rear: 3 mm (0.12 in) EBS00116 CHECKING THE WHEELS 1. Check: • wheel Damage/bends → Re[...]

3 - 36 CHK ADJ CHECKING AND LUBRICATING THE CABLES/LUBRICATING THE LEVERS, STEERING SHAFT AND STEERING KNUCKLES EBS00117 CHECKING AND LUBRICATING THE CABLES W ARNING _ A damaged cable sheath may cause corro- sion and interfere with the cab le move- ment. An unsafe condition may result so replace a damaged cable as soon as possi- ble. 1. Check: • [...]

CHK ADJ 3 - 37 EBS00120 ELECTRICAL SYSTEM CHECKING AND CHARGING THE BA TTER Y WARNING Batteries generate explosive hydr ogen gas and contain electrol yte which is made of poisonous and highly caustic sulfuric acid. Theref ore, always fo llow these preventive measures: • Wear pr otective eye gear when handling or working near batterie s. • Charg[...]

CHK ADJ 3 - 38 TIP Since VRLA (Valve Regulated Lead Ac id) batteries are sealed, it is not possible to check the charge state of the ba ttery by measuring the s pecif ic gra vity o f the electr olyte . Ther efore, the charge o f the batter y has to be checked by measurin g the vol tage at the batt ery term inals. 1. Remov e: • seat • batter y b[...]

CHK ADJ Example c. Open-circuit v oltage = 12.0 V d. Charging time = 6.5 hours e. Charge of the battery = 20 ~ 30% 5. Charge: • batter y (refe r to the appropriate charging method illustration) WARNING Do not quick charge a battery . • Never remove the VRLA (Valve Regulated Lead Acid) batter y sealing caps. • Do not use a high-rate batter y c[...]

CHK ADJ 3 - 40 • As shown in the f ollowing illustration, the open-circuit voltage of an VRLA (Va lve Regulated Lead Acid) battery stabilizes about 30 minutes after charging has been com pl ete d. Th ere for e, wai t 30 min ute s aft er ch a r g i n g i s c o m p l e t e d b e f o r e m e a s u r i n g the open-circuit v oltage . CHECKING AND CHA[...]

CHK ADJ 3 - 41 Charging method using a v ariable-current (v oltage) charger Measure the open-circuit volt age prior to charging. Connect a charger and ammeter to the batter y and star t charging. Is the amperage higher than the standard charg- ing amperage writt en on the batter y? Leav e the batter y unused f or more than 30 minutes bef ore measur[...]

CHK ADJ 3 - 42 Charging method using a constant voltage charger Measure the open-circuit v oltage prior to charging. Connect a charger and ammeter to the batter y and star t charging. Charge the batter y until the charging v oltage reaches 15 V . Leav e the batter y unused for more than 30 minutes before measuring its open-circuit voltage . This ty[...]

CHK ADJ 3 - 43 6. Install: • batter y 7. Connect: • batter y leads (to the batter y ter minals) NOTICE First, connect the positive battery lead , and then the negative battery lead . 8. Check: • batter y ter minals Dir t → Clean with a wire brush. Loose connection → Connect properly . 9. Lubricate: • batter y ter minals 10. Install: •[...]

CHK ADJ 3 - 44 EBS00121 CHECKING THE FUSES The following procedure applies to all of the fuses. NOTICE T o a v oid a short circuit, al ways set the main switch to “OFF” when checking or replac- ing a fuse. 1. Remov e: • seat Ref er to “SEA T , FENDERS AND FUEL T ANK”. 2. Check: • fuse a. Connect the pocket tester to the fuse and check t[...]

CHK ADJ 3 - 45 WARNING Never use a fuse with an amperage rating other than that specified. Impro vising 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 possibl y cause a fire . 4. Install: • seat Ref er to “SEA T , FENDERS AND [...]

4 - 1 ENG EBS00198 ENGINE ENGINE EXHAUST PIPE/MUFFLER, BREATHER HOSE AND LEADS Order Job/Part Q’ty Remarks Removing the exhaust pipe/muffler, breather hose and leads Remove the parts in the ord er listed. Rear fender Refer to “SEAT, FENDERS AND FU EL TANK” in chapter 3. 2 Exhaust pipe/muffler 1 3 Exhaust pipe gasket 1 4 Spark plug lead 1 5 Ge[...]

4 - 2 4 ENG ENGINE EBS00205 ENGINE MOUNTING BOLTS Order Job/Part Q’ty Remarks Removing the engine mounting bolts Remove the parts in the order listed. Carburetor Refer to “CARBURETOR” in chapter 5. 1 Drive chain 1 2 Lower engine mounting nut/bolt 1/1 3 Upper engine mounting nut/bolt 1/1 Refer to “INSTALLING THE ENGIN E”. 4 Engine assembly[...]

4 - 3 ENG ENGINE REMOVING THE ENGINE EBS00207 INSTALLING THE ENGINE 1. Install: • upper engine mounting bolt/nut • lower engine mounting bolt/nu t TIP Do not fully tighten the bolts and nuts. TIP The master link clip must be installed with the rounded end facing the direction of travel. 2. Tighten: • upper engine mounting nut • lower engine[...]

4 - 4 ENG CYLINDER HEAD 14 T R . . 11Nm (1.1m ． kg, 8.0ft ． lb) 2 T R . . 9Nm (0.9m ． kg, 6.5ft ． lb) 8 7 6 5 T R . . 12Nm (1.2m ． kg, 8.7ft ． lb) 15 12 12 13 E M T R . . 9Nm (0.9m ． kg, 6.5ft ． lb) 9 T R . . 12Nm (1.2m ． kg, 8.7ft ． lb) 11 T R . . 15Nm (1.5m ． kg, 10.8ft ． lb) T R . . 12Nm (1.2m ． kg, 8.7ft ． lb) 10 4 3[...]

4 - 5 ENG CYLINDER HEAD 14 Cyl. head assy . 1 1 15 Gask et, cylinder head 1 1 Order Job/Part Q’ty Remarks 1 1 C a p , c a m s h a f t 1 1 0 C y l . h e a d c o v e r a s s y . 1 F o r i n s t a l l a t i o n , r e v e r s e t h e r e m o v a l p r o c e d u r e . 1 6 G u i d e , s t o p p e r 1 1 12 Pin, dow el 4 13 Cam shaft comp . 1 1 7 G u i d[...]

4 - 6 ENG CYLINDER HEAD EBS00220 REMOVING THE CYLINDER HEAD 1. Align: • “T” mark on the rotor (with the stationary pointer on the crank- case) a. T ur n the crankshaft clockwise with a wrench. b . Align the “T” mar k on the rotor with the stationar y pointer on the crankcase. When the “T” mark is aligned with the sta- tionary pointer,[...]

4 - 7 ENG CYLINDER HEAD 3. Remove: cam shaft comp. cyl. head assy . TIP F asten a saf ety wire to the timing chain to pre v ent it from f alling into crankcase. EBS00224 CHECKING THE CAMSHAFT SPROCKET 1. Check: • camshaft sprocket Mor e t han 1/ 4 t oot h we ar → Re pl a ce th e cam shaft comp. and timing chain as a set. 1/4 of a tooth correct [...]

4 - 8 ENG CYLINDER HEAD EBS00230 CHECKING THE CYLINDER HEAD 1. Eliminate: • combustion chamber carbon deposits (with a rounded scraper) TIP Do not use a sharp instrument to av oid da mag- ing or scratching: • spark plug bore threads • valve seats 2. Check: • cylinder head Damage/scratches → Replace. 3. Measure: • cylinder head warpage O[...]

4 - 9 ENG CYLINDER HEAD EBS00233 INSTALLING THE CYLINDER HEAD 1. Install: cyl. head assy . 1 cam shaft c omp . cap , camshaft TIP Tighten the nuts in two stages and a crisscross pattern. 2. Install: • cam shaft comp. a. Rotate the camshaft to align the round h- ole in camshaft sproc ket a wa y from t- he cylinder head. b.Turn the cran kshaft cloc[...]

4 - 10 ENG CYLINDER HEAD i. If the mar ks are aligned, temporar ily tighten the camshaft sprock et bolt. If the mar ks are not aligned, change th e meshing posi tion of the camshaft sprock et and timing chain. 3. Install: bolt, flg. (small head) tensioner assy. W ARNIN G _ Always use a new gasket. 4. Adjust: • timing chain tensioner 5. Check: •[...]

4 - 11 ENG CAMSHAFT, ROCKER ARMS AND VALVES EBS00235 CAMSHAFT, ROCKER ARMS AND VALVES 1 4 4 5 5 T R . . 9Nm (0.9m ． kg, 6.5ft ． lb) T R . . 9Nm (0.9m ． kg, 6.5ft ． lb) 2 3 12 13 11 11 10 10 8 8 9 9 7 7 6 6 Order Job/Part Q’ty Remarks Removing the camshaft, rocker arms and valves Remove the parts in the order listed. Cylinder head Refer to[...]

4 - 12 ENG CAMSHAFT, ROCKER ARMS AND VALVES EBS00237 REMOVING THE ROCKER ARMS AND CAMSHAFT 1. Loosen: • locknuts • screw, valve adjusting 2. Remov e: • intake rocker arm shaft • exhaust rocker arm shaft • intake rocker arm • exhaust rocker arm TIP Remove the rocker arm shafts with the slide hammer bolt and weight . 3. Remov e: • camsh[...]

4 - 13 ENG CAMSHAFT, ROCKER ARMS AND VALVES 2. Remove: • valve cotters TIP Attach a valve spring compressor and attachment between the valve spring retainer and the cylinder head to r emove the valve cotters. Valve spring compressor P/N. YM-04019, 90890-04019 Valve spring compressor attach- ment P/N. YM-04108, 90890-04108 EBS00223 CHECKING THE CA[...]

4 - 14 ENG 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 diam eter Out of specification → Replace. Rocker arm inside diameter 1[...]

4 - 15 ENG CAMSHAFT, ROCKER ARMS AND VALVES EBS00240 CHECKING THE VALVES AND VALVE SPRINGS 1. Measure: • stem-to-guide clearance b Out of specification Replace the cylinder head ass'y. Stem-to-guide clearance = valve guide inside di ameter – valve stem diameter Stem-to-guide clearance Intake 0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in) <Limit&[...]

4 - 16 ENG 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 (0.0197 ~ 0.0354 in) Exhaust 0.6 ~ 1.0 mm (0.0236 ~ [...]

4 - 17 ENG CAMSHAFT, ROCKER ARMS AND VALVES 7. Measure: • valve seat width Out of specification → Reface the valve seat. a. Appl y Mechanic’ s b lueing dye (Dykem) to the v alv e fa ce. b . Install the valv e into the cylinder head. c. Press the valv e through the valv e guide and onto the v alve seat to make a clear patter n. d. Measure the [...]

4 - 18 ENG CAMSHAFT, ROCKER ARMS AND VALVES b . Apply molybdenum disulfide oil to the v alve stem. c. Install the valv e into the cylinder head. d. T ur n the valv e until the valv e face and valv e seat are ev enly polished, then clean off all of the compound. TIP _ For best lapping results, lightly tap the valve seat while rotating the valve back[...]

4 - 19 ENG 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. Install: • valve spring seats • valve stem seals • va[...]

4 - 20 ENG CAMSHAFT, ROCKER ARMS AND VALVES EBS00243 INSTALLING THE CAMSHAFT AND ROCKER ARMS 1. Install: • camshaft comp. TIP _ Be sure to align the round hole in camshaft 2. Apply: • engine oil (onto the rocker arm shafts) 3. Install: • rocker arms • rocker arm shafts TIP _ Use a slide hammer bolt to install the rocker arm shaft. sprocket [...]

4 - 21 CYLINDER AND PISTON EBS00245 CYLINDER AND PISTON Order Job/Part Q’ty Remarks Removing the cylinder and piston Remove the parts in the order listed. Refer to Cylinder head “CYLINDER HEAD”. Refer to 1 Cylinder “INSTALLING THE CYLINDER”. 1 2 Cylinder gasket 2 3 Dowel pin 2 4 Piston pin clip Refer to “REMOVING THE PISTON” and “IN[...]

4 - 22 ENG CYLINDER AND PISTON EBS00247 REMOVING THE PISTON 1. Remov e: • piston pin clips • piston pin • piston TIP • Before removing the piston pin clip, cover the cr ank cas e ope ni ng wit h a c lea n rag t o p rev en t t h e pi st on p in c li p f r o m fa ll in g i nt o th e c r a nk ca se . • Before removing each piston pin, deburr[...]

4 - 23 ENG CYLINDER AND PISTON b . If out of specification, rebore or replace the cylinder , and replace the piston and piston rings as a set. c. Measure piston skir t diameter “P” with the micrometer . 5 mm (0.20 in) from the bottom edge of the pis- ton d. If out of specificatio n, replace the piston and piston rings as a set. e. Calculate the[...]

4 - 24 ENG 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. TIP Before measuring the piston ring side clear- ance, eliminate any carbon deposits fro m the piston ring grooves and piston rings. 2. Install: • piston ring (into the[...]

4 - 25 ENG 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. Piston pin outside diameter 12.996 ~ 13.000 mm (0.5117 ~ 0.5118 in) <Lim[...]

120 ˚ 120 ˚ 120 ˚ b c a d e f f New 4 - 26 ENG CYLINDER AND PISTON EBS00252 INSTALLING THE PISTON 1. Install: • piston rings (onto the piston) TIP • Be sure to install the piston rings so that the manufacturer’s marks or numbers are located on the upper side of the rings. • Lubricate the piston and piston rings liberally with engine oil.[...]

4 - 27 ENG EBS00253 INSTALLING THE CYLINDER 1. Install: • cylinder TIP 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. • Pass the timing chain through the timing chain cavity. CYLINDER AND PISTON[...]

4 - 28 ENG C.D .I. MA GNET O C.D .I. MA GNET O EBS00256 Remarks Order Job/P ar t Q’ty 1 2 3 1 1 1 Dis as se mb le th e parts i n the o rd er li st ed. Refer to “CYLINDER HEAD”. D is c o n n ec t t h e C . D.I . m agn e t o l e a d coupler . F or installation, re verse the remo val pro- cedure. Removing the C.D.I. magneto Cover 2, Guide 1 and [...]

4 - 29 ENG C.D .I. MA GNET O REMO VING THE C.D.I. MA GNETO ROTOR 1. Remov e: nut plate washer TIP 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. Remov e: C .D .I. ma[...]

4 - 30 ENG INST ALLING THE C.D .I. MA GNETO ROTOR 1. Install: I NS T AL L IN G T H E P I CK U P C OI L A N D S T A T O R ASSEMBLY C .D .I. magneto rotor TIP Clean the tapered por tion of the crankshaft and the magneto rotor hub . When installing the magneto rotor , make sure the woodruff key is properly seated in the keyway of the crankshaft. 2. Ti[...]

4 - 31 ENG Remarks Order Job/P a r t Q’ty 1 2 3 1 1 2 EAS00316 BEL T DRIV E CRANKCASE CO VER Removing the belt drive Kickstarter Crankcase co ver - 1 Dowel pin Remov e the par ts in the order listed. For installation, reverse the removal pro- cedure. BEL T DRIVE 2 1 T R . . 12Nm (1.2m • kg, 8.7ft • lb) 3 3[...]

4 - 32 ENG Remarks Order Job/P ar t Q’ty 4 5 2 1 3 6 7 9 8 1 1 1 1 1 1 1 1 1 Remov e the par ts in the order listed. Ref er to “CRANKCASE COVER “. R e f e r t o “ I N S T A L L I N G T H E K I C K S T A R T E R “ . F or installation, re verse the remov al pro- cedure. EAS00338 KICKST AR TER Removing the kickstarter Crankcase, cov er Circl[...]

4 - 33 ENG BEL T DRIVE E A S 0 0 3 4 0 INST ALLING THE KICKST ARTER 1. Install: solid bush kickstarter shaft kickstarter spr ing 2. Hook: kickstar ter spring TIP Hook the spring end on the kic kstar ter shaft as shown, and hook the other end on the projection . 3. Install: plain washer circlip 4. Install: kick pinion gear kick pinion gear clip TIP [...]

4 - 34 ENG Remarks Order Job/P ar t Q’ty 1 2 3 4 5 6 8 9 10 11 12 13 1/1 1 1 1 1 1 1 1 1/1 1 1/6 3 1 Remov e the par ts in the order listed. Refer to “ REMOVING THE PRIMARY SHEA VE “. R e fe r to “ RE M O V I NG T H E S E C O ND A R Y SHEA VE AN D V- B E L T “. For installation, reverse the removal pro- cedure. Removi ng the V -belt, clut[...]

4 - 35 ENG Remarks Order Job/P ar t Q’ty 1 1 3 1 1 3 1 2 2 1 Disassemb le the par ts in the order listed. R e f er t o “ RE MO VI N G T HE S EC O N D A R Y SHEA VE AND V-BELT “. F or assembly , rev erse the disassembly procedure. D i s a s s e m b l i n g t h e s e c o n d a r y sheave Clutch carr ier nut Clutch carr ier Clutch shoe spring Co[...]

4 - 36 ENG E A S 0 0 3 1 7 REMO VING THE PRIMAR Y SHEA VE 1. Remov e: primar y sheave nut plate washer primar y fix ed sheav e - 1 TIP While holding the primar y fixed shea v e with the rotor holding tool , loosen the pr imary fixed sheav e nut. Rotor holding tool: 90890-01235 (YU-01235) E A S 0 0 3 1 8 REMO VING THE SECOND ARY SHEA VE AND V -BEL T[...]

4 - 37 ENG BEL T DRIVE EAS00319 DI SA SSE MBL IN G THE SEC ON D AR Y SHE A V E 1. Remov e: clutch carrier nut TIP Insta ll the c lutch s pr ing ho lder and c lutch spring holder arm onto the secondary sheav e as sho wn. Then, compress the spring, and re- mov e the clutch carr ier nut . Clutch spring holder 90890-01337 (YM-33285) (YM-33285-6) CHECKI[...]

4 - 38 ENG EAS00320 CHECKING THE V -BEL T 1. Check: V -belt Crac ks/damage/wear Replace. Grease/oil Clean the primar y 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 PRIMAR Y SHEA VE 1. Check: Primar y sliding sheave Primar y fix ed she[...]

4 - 39 ENG CHECKING THE SLIDER 1. Check: slider Damage/wear Replace EAS00322 CHECKING THE SECOND AR Y SHEA VE 1. Check: secondar y fixed shea ve secondar y sliding sheav e Cr ac ks/d amag e/we ar Rep lace the sec- onda r y fix ed and sliding sheav es as a set. 2. Check: torque cam groo ve Damage/wear Replace the secondary fix ed and sliding sheaves[...]

4 - 40 ENG 3. Install: slider primar y sliding sheav e cam BEL T DRIVE EAS00323 ASSEMBLING THE PRIMAR Y SHEA VE 1. Clean: primar y fixed sheav e primar y sliding sheave collar primar y sheave weights TIP Use thinner to clean up grease , dir t on the pri- mar y sliding sheav e cam side . 2. Install: primar y sheave weigh ts collar 2 2 2 2 2 2 3 3 1 [...]

4 - 41 ENG EAS00324 ASSEMBLING THE SECOND AR Y SHEA VE 1. Lubricate: seco ndary fix ed sheav e’ s inne r surf ace secondary sliding sheave’s inner surface torque cam g roove oil seals bearings (with the recommended lubricant) Recommended lubricant BEL-RA Y assembly lube 2. Install: secondar y sliding sheav e TIP Install the secondar y slidi ng [...]

4 - 42 2 1 ENG 5. Ins tall: secondar y sheav e spring clutch carrier TIP Attach the clutch spring holder and clutch spring holder arm onto the secondary sheav e a s s h o w n . T h e n , c o m p r e s s t h e s p r i ng , an d tighten the clutch carr ier nut . Clutch spring holder 90890-01337 (YM-33285) ( YM-33285-6) BEL T DRIVE EAS00325 INST ALLIN[...]

4 - 43 ENG 2. Install: clutch carrier nut TIP While holding the clutch carrier with the rotor holding tool , tighten the clutch carrier nut with the lockn ut wrench . Rotor holding tool 90890-01235 Locknut wrench 90890-01348 (YM-01348) 3. Install: clutch housing secondary sheave nut TIP T i g h t e n t h e s ec on d a r y sh e ave nu t w i th t h e[...]

4 - 44 ENG ST AR TER CLUTCH AND ST ARTER MO T OR Remarks Order Job/P a r t Q’ty 1 2 3 4 5 6 7 8 9 10 11 1 1 1 1 1 1 1 1 1 1 1 Disassem ble the par ts in the order listed. Ref er to “ REMO VING THE PRIMAR Y SHEA VE “ For installation, reverse the removal pro- cedure. R e m o v i n g th e s t a r t e r c l u t c h a n d starter motor Primar y s[...]

4 - 45 ENG CHECKING THE ST ARTER WHEEL GEAR 1. Check: star ter wheel gear idle gear Burrs/chips/roughness/wear Replace 2. Check: star ter clutch operation a. Install the sta r t er wheel g ear onto the idle g ea r and hold the star ter clutch. b . When tur ning the star ter wheel gear clock- wise , the star ter clutch and the star ter wheel gear sh[...]

4 - 46 ENG OIL PUMP Remarks Order Job/P a r t Q’ty 1 2 3 4 5 6 7 8 9 10 11 12 13 1 2 1 2 1 1 1 1 1 1 1 1 1 Disassembling the oil pump C.D .I. magneto Cov er O-ring Oil seal Dowel pin Nut Oil pump driven gear Dowel pin Oil pump body Outer rotor Inner rotor Oil pump shaft Oil pump housing cov er Dowel pin Remov e the par ts in the order listed. Ref[...]

4 - 47 ENG E A S 0 0 3 64 CHECKING THE OIL PUMP 1. Check: oil pump driven gear Crac ks/damage/wear Replace the de- f ective par t(s). 2. Measure: inner-roto r-to-outer-ro tor-tip clearan ce o u t e r - r o to r - t o- o i l -p u m p - ho u s i ng c l e a r - ance o i l - p u m p - h o u s i n g - t o - i n n e r - r o t o r - a n d - outer-rotor cl[...]

4 - 48 ENG EAS00376 INST ALLING THE OIL PUMP 1. Install: o-ring New oil pump assembly oil pump bolt After tightening the bolts, make sure the oil pump turns smoothly . 3. Check: oil pump operation Rou gh mo v eme nt Repe at s tep s (1) and (2) or replace the def ective par t(s). OIL PUMP 12 Nm (1.2 m • kg, 8.7 ft • lb) T R . . 2 2 1 1 NOTICE Ne[...]

4 - 49 ENG CRANKCASE AND CRANKSHAFT EBS00319 CRANKCASE AND CRANKSHAFT Remarks Order Job/P ar t Q’ty 1 2 3 4 5 6 7 8 9 1 2 1 1 1 1 1 1 1 Remove the par ts in the order listed. Refer to “ ENGINE “. Refer to “CYLINDER HEAD “. Refer to “CYLINDER AND PIST ON “. Refer to “V-BELT, CLUTCH, PRIMARY AND SECONDARY SHEAVE “. R e fe r t o “ [...]

4 - 50 ENG CRANKCASE AND CRANKSHAFT EBS00333 SEPARATING THE CRANKCASE 1. Remov e: • crankcase bolt 2 . Remov e: • r ight crankcase TIP T ap on one side of the crankcase with a soft- f ace hammer . T ap only on reinfo rced por tions of the crankcase , not on the crankcase mating surf aces. Work slowly and carefully and mak e sure the crankcase h[...]

4 - 51 ENG EAS00389 REMO VING THE CRANKSHAFT ASSEMBL Y 1. Remov e: crankshaft assemb ly timing chain TIP Bef ore removing the crankshaft assemb ly , rem o v e the timin g chain fr om the cran ksha ft sprock et. Th e c ra nk s ha f t as s em bly c a nn o t be r e - mov ed if the timing chain is attached onto the crankshaft sproc ket. EAS00207 CHECKI[...]

4 - 52 ENG EAS00394 CHECKING THE CRANKSHAFT AND CON- NECTING RO D 1. Measure: crankshaft runout Out of specification Re place the crank- shaft, bearing or both. TIP T ur n the crankshaft slowly . Maximum crankshaft runout 0.04 mm (0.0016 in) 2. Measure: big end side clearance Ou t of spec if ica tion R epl ac e the big end be ari ng , cra nk sh aft[...]

4 - 53 ENG 5. Check: crankshaft journal Sc rat ch es /w ea r Replace the crank- shaft. CRANK CASE AND CRA NKSHA FT EAS00408 INST ALLING THE CRANKSHAFT 1. Install: crankshaft assemb ly crankcase timing chain T o av oid scratching the crankshaft and to eas e the insta lla tio n pro ced ure, lubri cat e the oil seal lips with lithium-soap-based grease[...]

4 - 54 ENG EAS00418 ASSEMBLING THE CRANKCASE 1. Thoroughly clean all the gask et mating sur- f aces and crankcase mating surfaces . 2. Install: (onto the crankcase mating surf aces) 3. Install: dow el pins timing chain TIP Install the timing chain so it is not visible through the opening in the left crankcase . 4. Install: crankshaft crankcase (rig[...]

4 - 55 ENG EAS00419 TRANSMISSION Remarks Order Job/P a r t Q’ty 1 2 3 4 5 6 1 1 2 1 1 1 Re m ov i n g t h e l oc k wa s he r , dr i v e sprocket, and circlip T ransmission oil Crankcase co ver Belt drive Secondar y sheav e Crankcase co ver- 2 Crankcase co ver gask et- 2 Dowel pin Primar y drive gear shaft Main axle Drive axle Remov e the par ts i[...]

4 - 56 ENG EAS00425 CHECKING THE TRANSMISSION 1. Measure: main axle runout (with a centering de vice and dial gauge ) Out of specification Replace the main axle. Main axle runout limit 0.08 mm (0.0031 in) 2. Measure: primar y dr ive gear shaf t r unout (with a centering de vice and dial gauge ) Out of specification Replace the drive axle. Primary d[...]

5 - 1 CARB EBS00141 CARBURETOR CARBURETOR Order Job/Part Q’ty Remarks Removing the carburetor Remove the parts in the order listed. 1 Fuel overflow hose 1 2 Air vent hose 1 3 Fuel drain hose 1 7 Plunger assa y , star ter 1 8 Spring 1 5 Carburetor assembly 1 4 Fuel hose 1 6 P late 1 9 Manual starter comp 1 1 1 1 For installation, reverse the remov[...]

5 - 2 5 CARB CARBURETOR EBS00144 Order Job/Part Q’ty Remarks Disassembling the carburetor Remove the parts in the ord er listed. TIP 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. (2) (2) (3) Throttle stop screw 1 1 Cov er 1 Spr ing 1 Piston va[...]

5 - 3 CARB CARBURETOR Order Job/Part Q’ty Remarks Disassembling the carburetor Remove the parts in the order listed. Acceleration pump comp Carburet or warmer negative lead 1 Float chamber 1 Float pin 1 1 Float 1 Needle v alve 1 Main jet 1 Needle jet holder 1 Needle jet 1 Pilot jet 1 Plug 1 1 Spring F or assembly , rev erse the disassembly proced[...]

5 - 4 CARB CARBURETOR EBS00146 DISASSEMBLING THE CARBURETOR TIP 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. • float tang EAS00485 CHECKING THE CARBURET OR 1. Check: • carburetor body • float chamber Crac ks/damage Replace. • fuel passa[...]

5 - 5 CARB CARBURETOR 4. Check: 5. Check: 6 . Check: 8 . Check: • piston v alve Damage/scratches/wear Replace. • piston valv e diaphragm Crac ks/tears Replace. • v acuum chamber cover • piston v alve spring Crac ks/damage Replace. • jet needle • main jet • Needle jet holder • pilot jet Bends/damage/wear Replace. Obstruction Clean. B[...]

5 - 6 CARB CARBURETOR EBS00150 ASSEMBLING THE CARBURETOR TIP 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. • Before assembling the carburetor , wash all of the par ts in a petrole um-based sol- vent. • Alwa ys use a[...]

5 - 7 CARB CARBURETOR EAS00492 INST ALLING THE CARBURET OR 1. Adjust: • engine idling speed Engine idling speed 1,600 ~ 1,800r/min R e fer t o “ A D J U S T I N G T H E E N G I N E IDLING SPEED” in chapter 3. 2. Adjust: • throttle cable free pla y Thr ottle cab le free pla y (at the flange of the throttle grip) 1 ~ 3 mm (0.04 ~ 0.12 in) Ref[...]

5 - 8 CARB CARBURETOR EBS00154 MEASURING AND ADJUSTING THE FUEL LEVEL 1. Measure: • fuel level Out of specification → Adjust. a. Stan d the machine on a le vel s urf ace. b . Install the fuel lev el gauge onto the fuel drain pipe . c. Loosen the fuel drain screw . d. Hold the fuel le v el gauge v er tically next to the line on the float chamber[...]

6 - 1 CHAS EBS00378 CHASSIS FRONT AND REAR WHEELS FRONT WHEELS Order Job/Part Q’ty Remarks Removing the front wheels Remove the parts in the order listed. Place the machine on a level surface. W ARNIN G _ Securely support the machine so there is no danger of it falling over. The following procedure applies to both of the front wheels. 1 Cotter pi[...]

6 - 2 6 CHAS EBS00379 REAR WHEELS Order Job/Part Q’ty Remarks Removing the rear wheels Remove the parts in the order listed. Place the machine on a level surface. W ARNING _ Securely support the machine so there is no danger of it falling over. The following procedure applies to both of the rear wheels. 1 Cotter pin 1 Refer to “INSTALLING THE W[...]

6 - 3 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 . 3. Check: • wheel balance Out of balance → Adjust. W ARNING _ After replacing the ti[...]

6 - 4 CHAS FRONT AND REAR WHEELS W ARNING _ Eye protection is recommended when using striking tools. c. T o install the wheel bear ings, re v erse the abov e sequence. Use a sock et that matches outside diameter of bearing outer race to drive in beari ng. NOTICE Do not strike the center race or balls of the bearing. Contact should be made only with[...]

6 - 5 CHAS FRONT AND REAR WHEELS INSTALLING THE FRONT WHEELS The following procedure applies to both of the front wheels. 1. Install: • wheel TIP _ The arrow mark on the tire must point i n the direction of rotation of the wheel. 2. Tighten: • nuts T R . . 45 Nm (4.5 m · kg, 32.5 ft · lb) a INSTALLING THE REAR WHEELS The following procedure a[...]

FRONT BRAKES FRONT BRAKES Order Job/Part Q’ty Remarks Removing the front brakes Remo ve the parts in the order listed. Refer to “FRONT AND REAR WHEELS”. The following procedure applies to both of the front brakes. 1 Brake shoe 2 Refer to “INSTALLING THE FRONT BRAKES”. 2 Front brake cable (drum side) 1 3 Brake shoe plate 1 R e f e r t o ?[...]

6 - 7 CHAS FRONT BRAKES REMOVING THE FRONT BRAKES The following procedure applies to each brake. 1. Remov e: • brake camshaft lever • brake camshaft TIP 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. EBS00439 C H E C K I N G T H E F R O N T B R[...]

6 - 8 CHAS FRONT BRAKES 2. Check: • brake shoe lining surface Glazed areas → Remove. Use coarse sandpaper. TIP _ After using sandpaper, wipe off the polished particles with a cloth. 3. Measure: • brake shoe lining thickness Out of specification → Replace. Measuring points TIP Replace the brake shoes as a set if either is found to be worn to[...]

6 - 9 CHAS FRONT BRAKES 2. Check: • brake drum inner surface Oil/scratches → Remove. EBS00442 INSTALLING THE FRONT BRAKES The following procedure applies to both of the front brakes. Reverse the “Removal” procedure. Note the following points. 1. Lubr icate: • brake camshaft • pivot pin NOTICE _ During installation, lightly grease the br[...]

6 - 10 CHAS 3. Install: • brake shoe plate TIP When installing the brake shoe plate, align the groove of the brake shoe p late with the pro- jection of the steering knuckle. 4. Install: • front brake cable (drum side) • brake shoes TIP Check that the brake shoes are properly posi- tioned. 5. Check: • brake camshaft operation Unsmooth operat[...]

CHAS 6 - 11 EBS00382 REAR AXLE AND REAR AXLE HUB Order Job / P ar t Q’ty Remar ks Removin g the rear axle and rear axle hub Remov e the par ts in th e order listed. Rear wheels / rear wheel hubs Ref er to “FRONT AND REAR WHEELS”. 1 Nut 2 2 Lock washer 1 1 3 Brake caliper 1 TIP Do n o t ap p ly t h e re a r br a ke l e ve r a nd d o not u se t[...]

CHAS 6 - 12 Order Job / P ar t Q’ty Remar ks 4 Brak e disc / brake disc brac ket 1 / 1 5 Rear axle 1 Ref er to “REMO VING THE REAR AXLE”. 6 Driven sprock et / sprock et brack et 1 / 1 Ref er to “INST ALLING THE DRIVEN SPROCKET”. 7 Spacer 1 8 Chain puller 1 10 Bearing / oil seal 11 Bearing spacer 1 12 Bearing / oil seal 1 / 1 F or installa[...]

EBS00393 REMO VING THE REAR AXLE 1. Place the machine on a le vel surface . 2. Straight • lock washe r • nuts TIP • Apply the brake lever so that the rear axle does not tur n, when loosening the nut. • Use the axle nut wrench (36 mm) . 4. Ele v ate the rear wheels by placing the suit- able stand u nder the frame. 5. Remov e: • rear wheels[...]

CHECKING THE REAR AXLE 1. Check: • rear axle r unout Out of specification → Replace. WARNING Do not attempt to straighten a bent axle. CHECKING THE DRIVEN SPROCKET 1. Check: • dr iven sproc ket Ref er to “REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN”. INST ALLING THE DRIVEN SPROCKET 1. Install: • dr iven sproc ket TIP Make sure that th[...]

TIP CHAS 6 - 15 REAR AXLE AND REAR AXLE HUB EBS00397 INST ALLING THE REAR AXLE 2. Install: • Lock washer 1. Tighten: • nut Tigh ten th e n ut wit h rea r axle n ut wrench to s pe c i f i c a t i o n w hi le h ol di n g the rear axle. Axle nut wrench (36 mm) 90890-01422 YM-37132 TIP 3. Tighten: • nut Tigh ten th e n ut wit h rea r axle n ut wr[...]

CHAS 6 - 16 EBS00400 REAR BRAKE REAR BRAKE P ADS Order Job / P ar t Q’ty Remar ks Removin g the rear brake pads Remov e the par ts in th e order listed. The follo wing procedure applies to both of the rear brak e calipers. R e a r wheel Refer to “FRONT AND REAR WHEELS”. 1 Brake pad 2 2 Brake pad spring 1 F or installation, rev erse the remov [...]

CHAS 6 - 17 EBS00402 NOTICE Disc brake components rarely require dis- assembly . DO NO T: • disassemble components unless abso- lutely necessary; • use solvents on internal brake compo- nents; • use spent brake fluid for cleaning; (use only c l ean brake fluid) • allow brake fluid to come in contact with the eyes, as this ma y cause eye inj[...]

CHAS 6 - 18 5. Check: • brake le ver operation Soft or spo ngy f eeli ng → Bleed the brake system. Ref er to “BLEEDING THE HYDRAULIC BRAKE SYSTEM” in chapter 3. c. Tighten the brake caliper b leed screw . d. Install a new brak e pad spring and new brak e pads. 3. Install: • brake caliper • brake caliper mounting bolts 4. Check: • brak[...]

CHAS 6 - 19 EBS00407 REAR BRAKE MASTER CYLINDER Order Job / P ar t Q’ty Remar ks Removin g the rear brake master cylinder Remov e the par ts in the order li sted. Brak e fluid Drain. Refer to “BLEEDING THE HYDRA ULIC BRAKE SYSTEM” in chapter 3. 1 Brake fluid reservoir cap 1 2 Brak e fluid reser voir diaphr agm 1 3 F ront brake light s witch 1[...]

CHAS 6 - 20 EBS00413 CHECKING THE MASTER CYLINDER 1. Check: • brake master cylinder Wea r / scratches → Replace the brake mas- ter cylinder assembly . • brake master cylinder body Crac ks / damage → Replace. • brake fluid deliv er y passage (brak e master cylinder body) Blockage → Blow out with compressed air . 3. Check: • rear brake [...]

CHAS 6 - 21 EBS00418 INST ALLING THE REAR BRAKE MASTER CYLINDER 1. Install: • brake master cylinder TIP • The “UP” mark on the brake master cylinder brac ket should f ace up. • Install the brake master cylinder so that the gaps between the brake master cylinder and the brak e master cylinder bracket are equal. 2. Install: • copper washe[...]

CHAS 6 - 22 3. Fill: • brake fluid reser voir NOTICE Brake fluid may damage painted surfaces or plastic par ts. Always clean up spilled brake fluid immediately . WARNING • Use only the desig nated quality brake fluid: other brake fluids may deteriorate the rubber seals, causing leakage and poor brake performance. • Refill with the same type o[...]

CHAS 6 - 23 REAR BRAKE Order Job / Par t Q’ty Remarks Removing the rear brake caliper Remov e the par ts in the order listed. Brak e fluid Drain. Refer to “BLEEDING THE HYDRA ULIC BRAKE SYSTEM” in chapter 3. 2 Union bolt 1 Parking brake cable 1 3 Copper washer 2 4 Brake hose 1 Disconnect. 5 Brak e caliper assembly 1 For installation, re verse[...]

CHAS 6 - 24 Order Job / Par t Q’ty Remarks Remov e the par ts in the order listed. For assemb ly , re verse the disassemb ly procedure. REAR BRAKE Disassembling the rear brake cali- per Adjusting bolt 1 Lockn ut 1 P ar king brake arm 1 Bracket brake bracket 1 Parking brake case 1 Brak e pad 2 Brak e pad spring 1 Caliper brac ket 1 Brak e caliper [...]

CHECKING THE REAR BRAKE CALIPER Recommended brake component replacement schedule Brake pads As required Caliper ass'y Every two years Brake hoses Every four years Brake fluid Repl ace when brakes are disassembled. 1. Check: • brake caliper body Cracks / damage → Replace. • brake fluid deliv er y passage (brak e caliper body) Blockage →[...]

6 - 26 EBS00436 INST ALLING THE REAR BRAKE CALIPER 1. Install: • brake caliper assemb ly • brake caliper mounting bolts • brake hose • copper washers • union bolt Brake caliper mounting bolt 35 Nm (3.5 m•kg, 25.3 ft•lb) Union bolt 28 Nm (2.8 m•kg, 20.3 ft•lb) NOTICE When installing the brake hose on the brake caliper , make sure t[...]

CHAS 6 - 27 WARNING • Use only the designated quality brake fluid: other brake fluids ma y deteriorate the rubber seals, causing leakage and poor brake performance. • Refill with the same type of brake fluid: mixing brake fluids ma y result in a harm- ful chemical reaction and lead to poor brake performance. • Be careful that water does not e[...]

6 - 28 CHAS STEERING SYSTEM EBS00444 STEERING SYSTEM HANDLEBAR Order Job/Part Q’ty Remarks Removing the handlebar Remove the parts in the order listed. Handlebar cover Refer to “SEAT, FENDERS AND FUEL TANK” in chapter 3. 1 Handlebar grip 2 Refer to “REMOVING THE HANDLEBAR GRIPS” and “INSTALLING THE HAN- DLEBAR GRIPS”. 2 Front brake ca[...]

6 - 29 CHAS Order Job/Part Q’ty Remarks 11 Upper handlebar holder 2 10 Parking brake lever 1 Refer to “INSTALLING THE HANDLE- BAR”. 12 Handlebar 1 For installation, reverse the removal pro- cedure. STEERING SYSTEM 1 1 2 3 4 5 6 7 8 9 11 12 (4) (2) (2) LS T R . . 14 Nm (1.4 m • kg, 10.1 ft • Ib) T R . . 14 Nm (1.4 m • kg, 10.1 ft • Ib)[...]

6 - 30 CHAS STEERING SYSTEM EBS00447 REMOVING THE HANDLEBAR GRIPS 1. Remove : • handlebar grips TIP _ Blow compressed air between the han dlebar and ha ndlebar gr ip, and gradually push the grip off the handlebar. EBS00445 REMOVING THE REAR BRAKE SWITCH 1. Remove : • rear brake switch TIP _ Push the fastener when removing the rear brake switch [...]

6 - 31 CHAS STEERING SYSTEM EBS00449 INSTALLING THE HANDLEBAR 1. Install: • handlebar • upper handlebar holders TIP • Install the handlebar, please align the punch mark and the gap at handlebar holder . • The upper handlebar holders should be installed with the flange forward . NOTICE _ First tighten the bolt on the rear side of the handleb[...]

6 - 32 CHAS STEERING SYSTEM EBS00451 INSTALLING THE REAR BRAKE MASTER CYLINDER 1. Install: • handlebar switch TIP • Insta lli ng the re ar br ake ma st er cyli nde r , ma ke sure the handlebar switch , handlebar grip , and brake master cylinder are in the positions shown in the illustration. EBS00452 INSTALLING THE FRONT BRAKE LEVER ASSEMBLY 1.[...]

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 TIP Align the holder plate on the handlebar with the align position of the parking brake lever. 2. Adjust: • parking brake Refer to “ADJUSTING THE PARKING BR[...]

T R . . 35 Nm (3.5 m • kg, 25.3 ft • Ib) New LS T R . . 25 Nm (2.5 m • kg, 18.1 ft • Ib) T R . . 35 Nm (3.5 m • kg, 25.3 ft • Ib) 1 2 3 New New 2 4 New T R . . 55 Nm (5.5 m • kg, 39.8 ft • Ib) 5 6 - 34 CHAS STEERING SYSTEM EBS00454 STEERING STEM Order Job/Part Q’ty Remarks Removing the steering stem Remove the parts in the ord er [...]

6 - 35 CHAS STEERING SYSTEM EBS00455 REMOVING THE STEERING STEM 1. Remove: • steering stem TIP 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. W ARNIN G _ Do not attempt to straighten a bent stem; this may dangerously weaken [...]

6 - 36 CHAS STEERING SYSTEM INSTALLING THE STEERING STEM 1. Tighten: • steering stem nut • tie-rod end nut TIP When tightening each tie-rod end nut , hol d the tie-rod ball joint with a 14-mm wrench . T R . . 55 Nm (5.5 m • kg, 39.8 ft • Ib) T R . . 35 Nm (3.5 m • kg, 25.3 ft • Ib) TIP The lo wer han dle bar ho lde r an d st ee ri n g s[...]

CHAS 6-37 EBS00460 TIE-RODS AND STEERING KNUCKLES Order Job / P ar t Q’ty Remar ks Removing the tie-r ods and steering knuc kles Remov e the par ts in the order listed. The follo wing proced ure applies to both of the tie-rods and steering knuckles . Refer to “FR ONT BRAKES”. 1 Tie-rod 1 Refer t o “INST ALLING THE TIE-RODS”. 2 F ront bump[...]

6 - 38 CHAS STEERING SYSTEM EBS00461 REMOVING THE TIE-RODS The following procedure applies to both of the tie-rods. The following procedure applies to both of the steering knuckles . 1. Remove: • tie-rod TIP When removing the tie-rod, hold each tie-rod ball joint with a 14-mm wrench and then loosen the tie-rod end nut. EBS00462 CHECKING THE TIE-R[...]

6 - 39 CHAS EBS00465 INSTALLING THE TIE-RODS The following procedure applies to both of the tie-rods. 1. Install: • tie-rod TIP • The tie-rod side which must be installed on the outside has grooves . • When installing the tie-rod, hold each tie-rod ball joint with a 14-mm wrench and then tighten the tie-rod end nut. 2. Adjust: • toe-in Refe[...]

CHAS 6 - 40 EBS00460 FRONT ARMS AND FRONT SHOCK ABSORBER ASSEMBLIES Order Job / P ar t Q’ty Remar ks Removing the tie-r ods and steering knuc kles Remov e the par ts in the order liste d. The follo wing procedure applies to both of the tie-rods and steering knuckles . Refer to “FR ONT BRAKES”. 1 Tie-rod 1 Disconnect. 2 F ront bumper 1 3 Lower[...]

A A B B CHAS 6 - 41 EBS00469 REMO VING THE FRONT ARMS 1. Check: • front ar m free play a. Check the fron t ar m side play by moving it from side to side. If side play is noticeable , check the bush- ings. b . Check t he front arm ver tical movement by mo ving it up and down. If the vertical movement is tight or rough, or if there is binding, chec[...]

CHAS 6 - 42 EBS00472 CHECKING THE BALL JOINTS The f ollowing procedure applies to both of the front ar m ball joints. 1. Check: • ball joint Damage/pitting → Replace the front ar m. F ree play → Replace the front arm. T ur ns roughly → Replace the front ar m. EBS00473 INST ALLING THE FR ONT ARMS The f ollowing procedure applies to both of t[...]

CHAS 6 - 43 REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN Order Job / P ar t Q’ty Remar ks Removin g the rear shock absorber , swingarm and drive c hain Remov e the par ts in the order listed. Seat / rear fender / air filter case Ref er to “SEA T , FENDERS AND FUEL T ANK” in chapter 3. Rear axle hub Refer to “REAR AXLE AND REAR AXLE HUB”.[...]

CHAS 6 - 44 REAR SHOCK ABSORBER , SWINGARM A ND DRIVE CHAIN Order Job / P ar t Q’ty Remar ks 9 Drive chain case 1 1 10 Loc k washer 1 11 Drive sproc ket 1 12 Drive chain 1 13 Dust cov er 15 Bushing 1 16 Spacer 2 For installation, re verse the remo v al procedure. Ref er to “INST ALLING THE DRIVE SPROCKET”. 2 14 Drive chain guide 2 T R . . 35 [...]

EBS00478 CHECKING THE REAR SHOCK ABSORBER 1. Check: • shock absorber Oil leaks → Re pl ac e t he re ar sh o ck a b so rb e r assembly. • shock absorber rod Bends/damage → Replace the r e a r s h o c k absorber assembly. • spring Fatigue → Re place the rear sh ock abso rber assembly. Move the spring up and down. CHAS 6 - 45 EBS00487 REMO[...]

CHAS 6 - 46 c. Check the s wingar m ver tical movement by mo ving it up and down. If ver tical mov ement is tight or rough, or if there is binding, check the spacer , bear ings and frame piv ot. 2. Remov e: • pivot shaft nut • pivot shaft • s wingar m EBS00495 CHECKING THE SWINGARM 1. Check: • s wingar m Bends / cracks / damage → Replace.[...]

CHAS 6 - 47 EBS00496 CHECKING THE DRIVE CHAIN 1. Measure: • 15-link section of the drive chain Out of specification → Replace the drive chain. TIP • While measuring the 15-link section, push down on the drive chain to increase its ten- sion. • Mea sure the length between drive chain roller and as shown. • P erf or m this measurement at tw[...]

CHAS 6 - 48 4. Check: • dr ive chain rollers Damage / wear → Replace the drive chain. • dr ive chain side plates Crac ks / damage / wear → Replace the dr ive chain. 5. Lubricate: • dr ive chain REAR SHOCK ABSORBER , SWINGARM A ND DRIVE CHAIN 6. Check: • dr ive sproc ket • dr iven sproc ket More than 1 / 4 tooth wear → Replace the dr[...]

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

7 - 2 – + 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 . Always insert the probes f[...]

7 - 3 – + ELEC CHECKING THE SWITCHES EBS01029 CHECKING THE SWITCHES Check each switch for damage or wear, proper connections, and also for continuity between th e ter- minals. Refer to “CHECKING SWITCH CONTINUITY”. Damage/wear Repair or replace. Improperly connected Properly connect. Incorrect continuity reading Replace the switch. ON OFF B B[...]

7 - 4 – + ELEC IGNITION SYSTEM EBS00503 IGNITION SYSTEM CIRCUIT DIAGRAM C.D.I. magneto Main switch C.D.I. unit Ignition coil Spark plug Engine stop switch (handlebar) W / R W W B W W R B / R B / G W / B W / R B / R B / W Br B ON OFF OFF ON ON OFF W W W / R B R R Y / R Y / R Br B W W R B R W / B L / W R B B B B 10A L / W L / W G / Y R R R 11 12 15[...]

7- 5 – + ELEC IGNITION SYSTEM EBS01045 TROUBLESHOOTING Check: 1. s park plug 2. ignition spark gap 3. spar k plug cap resistance 4. ignition coil resistance 5. main switch 6. e ngine stop s witches 7. w iring connections (o f the entire ignition system) TIP • Before troubleshooting, remov e the following part(s): 1. seat 2. f ront f ender 3. fu[...]

7 - 6 – + ELEC IGNITION SYSTEM EBS01034 NO YES EBS01036 YES NO 2. Ignition spark gap • Disconnect the spark plug cap from the spark plug. • Connect the ignition dynamic spark tester as shown. Spark plug cap Spark plug • Set the main switch to “ON ”. • Measure the ignition spark gap . • Crank the engine by pushing the starter switch [...]

7-7 – + ELEC IGNITION SYSTEM EBS01038 YES NO EBS01041 YES NO EBS01042 YES NO 4. Ignition coil resistance • Disconnect the ignition coil connectors from the ignition coil terminals. • Connect the pocket tester ( Ω × 1) to the ignition coil as shown. Positive tester probe → black terminal Negative tester probe → green terminal • Measur[...]

7 - 8 – + ELEC IGNITION SYSTEM EBS01040 YES NO EBS01099 YES NO EBS01047 YES NO 7. Pickup coil resistance • Disconnect the C.D.I. magnet o coupler from the wire harness. • Connect the pocket tester ( 100) to the pickup coil terminal as shown. Positive tester probe white/black terminal Negative tester probe white/red terminal • Measure the pi[...]

7 - 9 – + 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 Rear brake switch Start switch W / R W W B W W R B / R B / G W / B W / R B / R B / W Br B ON OFF OFF ON ON OFF W W W / R B R R Y / R Y / R Br B W W R B R W [...]

7 - 10 – + ELEC ELECTRIC STARTING SYSTEM EBS00507 STARTING CIRCUIT OPERATION The starting circuit on this model consists of t h e s t a r t e r m o t o r , s t a r t e r r e l a y , r e a r b r a k e switch. If the main switch is on and the engine stop switch is in the ON position, t he starter motor can be operated only if: Main fuse Battery Sta[...]

7 - 11 – + ELEC ELECTRIC STARTING SYSTEM EBS01050 TROUBLESHOOTING Check: 1. main fuse 2. batter y 3. star ter motor 4. star ter rela y 5. main s witch 6. rear brake switch 7. star t s witch 8. wi ring connections (of the entire starting system) TIP • Before troubleshooting, remove the foll owing part(s): 1. seat 2. fro nt f ender 3. rear f ende[...]

7 - 12 – + ELEC ELECTRIC STARTING SYSTEM EBS01054 YES NO EBS01041 YES NO EBS01046 YES NO EBS01057 YES NO 4. Star ter relay • Disconnect the starter relay coupler from the coupler. • Connect the pocket tester ( Ω × 1) and bat- tery (12 V) to the starter relay coupler as shown. Positive battery terminal → red/white Negative battery termina[...]

7 - 13 – + ELEC STARTER MOTOR EBS01061 STARTER MOTOR Order Job/Part Q’ty Remarks Removing the starter motor Remove the parts in the order listed. 1 Starter motor lead 1 2 Ground lead 1 3 Starter motor 1 For installation, reverse the removal pro- cedure. Disassembling the starter motor Remove the parts in the order listed. Yoke 1 Refer to “ASS[...]

7 - 14 – + 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. 3. Measure: • mica undercut Out of specification → Scrape the mica to the proper measurement with a hacksaw blade that has be[...]

7 - 15 – + ELEC STARTER MOTOR 5. Measure: • brush length Out of specification → Replace the brushes as a set. 6. Measure: • brush spring force Out of specification → Replace the brush springs as a set. 7. Check: • gear teeth Damage/wear → Replace the gear. 8. Check: • bearing • oil seal • O-rings Damage/wear → Replace the defe[...]

7 - 16 – + ELEC CHARGING SYSTEM EBS00516 CHARGING SYSTEM CIRCUIT DIAGRAM C.D.I. magneto Rectifier/regulator Main fuse Positive battery l ead Battery Negative battery lead W / R W W B W W R B / R B / G W / B W / R B / R B / W Br B ON OFF OFF ON ON OFF W W W / R B R R Y / R Y / R Br B W W R B R W / B L / W R B B B B 10A L / W L / W G / Y R R R 11 1[...]

7 - 17 – + ELEC CHARGING SYSTEM EBS01065 TROUBLESHOOTING Check: 1. main fuse 2. batter y 3. c harging v oltage 4. c harging coil resistance 5. w iring connections (of the entire charging system) TIP _ • Before troubleshooting, remov e the following part(s): 1. seat 2. rear f ender • Troubleshoot with the following special tool(s). EBS01043 YE[...]

7 - 18 – + ELEC CHARGING SYSTEM EBS01066 NO YES EBS01100 YES NO EBS01059 YES NO 3. Charging voltage • Connect the engine tachometer to the spark plug lead. • Connect the pocket tester (DC 20 V) to the battery as shown. Positive tester probe → positive battery terminal Negative tester probe → negative battery terminal • Start the engine [...]

8 - 1 TRBL SHTG EBS00537 TROUBLESHOOTING TIP 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 Fuel tank • Empty • [...]

8 - 2 TRBL SHTG STARTING FAILURE/HARD STARTING/POOR IDLE SPEED PERFORMANCE/POOR MEDIUM AND HIGH-SPEED PE RFORMANCE COMPRESSION SYSTEM Cylinder and cylinder head • Loose spark plug • Loose cylinder head or cylinder • Broken cylinder head gasket • Broken cylinder gasket • Worn, damaged or seized cylinder Valve, camshaft and crankshaft • I[...]

8 - 3 TRBL SHTG FAULTY GEAR SHIFTING/CLUTCH SLIPPING/ DRAGGING/OVERHEATING EAS00853 F A UL TY CLUTCH ENGINE OPERA TES BUT VEHICLE WILL NOT MOVE V -belt • Bent, damaged or wor n V -belt • Slipping V -belt Primary pulle y cam and primary pulle y slider • Damaged or worn primar y pulley cam • Damaged or worn pr imar y pulley slider Clutch spri[...]

8 - 4 TRBL SHTG FAULTY BRAKE/SHOCK ABSORBER MALFUNCTION/ UNSTABLE HANDLING EBS00549 FAULTY BRAKE POOR BRAKING EFFECT Front drum brake • Worn brake shoe lining • Worn brake drum • Oily or greasy brake shoe lining • Oily or greasy brake drum • Improperly adjusted brake lever free play • Improper brake cam lever position • Improper brake[...]

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Y AMAHA MO T OR CO. , L TD . 2500 SHINGAI IW A T A SHIZUOKA JAP AN PRINTED IN U.S.A.[...]

YFM90R WIRING DIAGRAM W / R W W B W W R B / R B / G W / B W / R B / R B / W Br B ON OFF OFF ON ON OFF W W W / R B R R Y / R Y / R Br B W W R B R W / B L / W R B B B B 10A L / W L / W G / Y R R R C.D.I. magneto Main switch Rectifier/regulator Main fuse Positive battery le ad Battery Negative batt ery lead Starter relay Starter motor C.D.I. unit Igni[...]