Yamaha YQ50 Service Manual
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97
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YQ50
5BS-AE2
SERVICE
MANUAL

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Summary of Contents for Yamaha YQ50

  • Page 1 YQ50 5BS-AE2 SERVICE MANUAL...
  • Page 2 YQ50 SERVICE MANUAL © 1997 by MBK INDUSTRIE 2st Edition, November 1997 All rights reserved. Any reprinting or unauthorized use without the written permission of MBK INDUSTRIE is expressly prohibited.
  • Page 3 It is not possible to put an entire mechanic’s education into one manual, so it is assumed that persons using this book to perform maintenance and repairs on YAMAHA and MBK scooters have a basic understanding of the mechanical concepts and procedures inherent in scooter repair technology.
  • Page 4 HOW TO USE THIS MANUAL CONSTRUCTION OF THIS MANUAL This manual consists of chapters for the main categories of subjects. (See «illustrated symbols). 1st title 1 This is a chapter with its symbol on the upper right of each page. 2nd title 2 This title appears on the upper of each page on the left of the chapter symbol.
  • Page 5: General Information

    ILLUSTRATED SYMBOLS (REFER TO THE ILLUSTRATION) SPEC INFO Illustrated symbols Q to W are designed as thumb tabs to indicate the chapter’s number and content. INSP Q General information W Specifications E Periodic inspection and adjustment R Engine CARB CHAS T Carburetion Y Chassis U Electrical...
  • Page 6 INDEX GENERAL INFORMATION INFO SPECIFICATIONS SPEC PERIODIC INSPECTION INSP AND ADJUSTMENT ENGINE OVERHAUL COOLING SYSTEM CARBURETION CARB CHASSIS CHAS ELECTRICAL ELEC TROUBLESHOOTING TRBL SHTG...
  • Page 7 INFO...
  • Page 8: Table Of Contents

    INFO CHAPTER 1. GENERAL INFORMATION SCOOTER IDENTIFICATION ................ 1-1 VEHICLE IDENTIFICATION NUMBER ............ 1-1 ENGINE SERIAL NUMBER ..............1-1 IMPORTANT INFORMATION ............... 1-2 ALL REPLACEMENT PARTS ..............1-2 GASKETS, OIL SEALS, AND O-RINGS ..........1-2 LOCK WASHERS/PLATES AND COTTER PINS ........1-2 BEARINGS AND OIL SEALS ..............
  • Page 9: Scooter Identification

    INFO SCOOTER IDENTIFICATION GENERAL INFORMATION SCOOTER IDENTIFICATION VEHICLE IDENTIFICATION NUMBER The vehicle identification number Q is stamped into the frame. NOTE: The vehicle identification number is used to identify your scooter and may be used to register your scooter with the licensing authority in your state.
  • Page 10: Important Information

    ALL REPLACEMENT PARTS 1.Use only genuine parts for all replacements. Use oil and/or grease recommended by MBK/ YAMAHA for assembly and adjustment. Other brands may be similar in function and appearance, but inferior in quality. GASKETS, OIL SEALS, AND O-RINGS 1.All gaskets, seals and O-rings should be...
  • Page 11: Circlips

    INFO IMPORTANT INFORMATION CIRCLIPS 1.All circlips should be inspected carefully before reassembly. Always replace piston pin clips once they have been removed. Replace bent circlips. When installing a circlip Q make sure that the sharp edge W is positioned opposite to the thrust E it receives.
  • Page 12: Special Tools

    SPECIAL TOOLS INFO EB102000 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. When placing an order, refer to the list provided below to avoid any mistakes.
  • Page 13 INFO SPECIAL TOOLS Tool N° Tool name/usage Illustration 9079Q-02218 Ring nut wrench. This tool is used to loosen and tighten the steering ring nut. 90890-01326 T-handle Damper rod holder 90890-1294 These tools are used for holding the damper rod holder when removing or in- stalling the damper rod holder.
  • Page 14 SPEC...
  • Page 15 SPEC CHAPTER 2. SPECIFICATIONS GENERAL SPECIFICATIONS ............... 2-1 MAINTENANCE SPECIFICATIONS .............. 2-4 ENGINE ....................2-4 CHASSIS ....................2-6 ELECTRICAL ................... 2-7 CABLE ROUTING ..................2-8...
  • Page 16: General Specifications

    Compression ratio 7.9 : 1 (F)(B)(P)(E)(I) 8 : 1 (D)(NL)(CHE) Starting system Electric and kick starter Lubrication system: Separate lubrication (Yamaha Autolube ) Oil type or grade: Engine oil: Semi-synthetic, in accordance with the API TC TSC 3 Standard. Transmission oil...
  • Page 17 SPEC GENERAL SPECIFICATIONS Model YQ50 Carburetor: Type/Manufacturer PHBN12HS / DELL'ORTO Spark plug: Type/Manufacturer BR8HS/NGK 0.5 ~ 0.7 mm Clutch type: Dry, centrifugal automatic Transmission: Primary reduction system Helical gear Primary reduction ratio 52/13 (4.000) Secondary reduction system Spur gear Secondary reduction ratio 43/14 (3.071)
  • Page 18 SPEC GENERAL SPECIFICATIONS Model YQ50 Electrical: Ignition system Charging system Flywheel magneto Battery type/model GM4-3B, YB4L-B, FB4L-B Battery capacity 12V 4AH Headlight type: Bulb Bulb wattage / quantity: Headlight 12V 35W/35W x 1 Auxiliary light 12V 5W x 1 Taillight/brake light...
  • Page 19: Maintenance Specifications

    SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Model YQ50 Cylinder head: Warp limit 0.02 mm Lines indicate straight edge measurements. Cylinder: Bore size 39.993 ~ 40.012 mm <Limit> <40.1 mm> Taper limit 0.05 mm Piston: Piston size 39.957 ~ 39.977 mm...
  • Page 20 SPEC MAINTENANCE SPECIFICATIONS Model YQ50 Automatic centrifugal clutch: Clutch shoe thickness 2.0 mm <Wear limit> <1.0 mm> Clutch shoe spring free length 29.9 mm Clutch housing inside diameter 107.0 mm <Wear limit> 107.4 mm Clutch-in revolution 3.950 ~ 4.450 r.p.m.
  • Page 21: Chassis

    SPEC MAINTENANCE SPECIFICATIONS CHASSIS Model YQ50 Steering system: Steering bearing type Ball bearing No/Size of steel balls: Upper 15 pcs (4.75 mm) Lower 15 pcs (4.75 mm) Front suspension: Front fork travel 80 mm Spring rate (K1) 5.7 N/mm Stroke (K1)
  • Page 22: Electrical

    SPEC MAINTENANCE SPECIFICATIONS ELECTRICAL Model YQ50 Voltage: 12 V Ignition system: Ignition timing (B.T.D.C.) 14° at 5.000 r/min CDI: 400 ~ 600 Ω at 20°C (68°F) (White/Red-Black) Pickup coil resistance (color) 640 ~ 960 Ω at 20°C (68°F) (Black/Red-Black) Source coil resistance (color)
  • Page 23: Cable Routing

    SPEC CABLE ROUTING A Push the end grip againt the handlebar and tighten to 0.6 ~ 0.8 m.kg. CABLE ROUTING B Tighten the front screw first. Q Handlebar end grip C Apply the left switch handle against the handlebar. W Right handlebar switch D Hole for the front flasher harness.
  • Page 24 SPEC CABLE ROUTING A Insert the fuel sender completly. CABLE ROUTING B Turn the fuel sender so that the cable points toward. Q Fuel sender C Pass the fuel lines above the rear brake hose. W Fuel tank D Pass the fuel overflow pipe in the trunk slot. E Fuel overflow pipe E Push the fuel cock (without turning it) completly in the tank and screw R Fuel cock...
  • Page 25 SPEC CABLE ROUTING A Set the seat lock adjuster so that there is a gap betwween 8 ~ 9 mm Q Seat lock W Starter motor at the seat lock aperture. B Install the starter relay on the footrest board. E Ignition coil C Group the connections here.
  • Page 26 SPEC CABLE ROUTING Q Wiring harness A Install the wiring harness in the middle of the frame. W Resistor B Set the resistor at 45°0/+30’ on the frame bracket. E Horn C Clip the front brake hose on the front fork bracket. R Front brake hose D Install the 8 clamps just beside the marks at the end side of the hoses.
  • Page 27 SPEC CABLE ROUTING Q Rear brake hose A Install the rear brake hose in the clip. W Seat lock cable B Install the oil delivery hose (from oil pump to carburator) under the E Wire harness water hose. R Throttle cable C Pass the rear brake hose under the frame reinforcement tube.
  • Page 29 CHAPTER 3. PERIODIC INSPECTION AND ADJUSTMENT INTRODUCTION .................... 3-1 PERIODIC MAINTENANCE/LUBRICATION INTERVALS ......3-1 COVERS ......................3-3 REMOVAL ....................3-3 HANDLEBAR COVERS ................. 3-7 REMOVAL ....................3-7 ENGINE ....................... 3-11 ENGINE IDLE SPEED ADJUSTMENT ..........3-11 THROTTLE CABLE FREE PLAY ADJUSTMENT ......... 3-12 SPARK PLUG INSPECTION ..............
  • Page 30: Introduction

    • Correct if necessary. Items marked with an asterisk ( * ) require special tools, data and technical skills for servicing. Take the scooter to a Yamaha or MBK Dealer when servicing these items. ** : Medium weight wheel bearing grease.
  • Page 31 INSP PERIODIC MAINTENANCE/LUBRICATION INTERVALS NOTE: Brake fluid replacement: 1.When disassembling the master cylinder or caliper cylinder, replace the brake fluid. Normally check the brake fluid level and add fluid as required. 2.On the inner parts of the master cylinder and caliper cylinder, replace the oil seals every two years. 3.Replace the brake hoses every four years, or when cracked or damaged.
  • Page 32: Covers

    INSP COVERS REMOVAL 8 Nm (0,8 m.kg) 3 Nm (0,3 m.kg) 8 Nm (0,8 m.kg) 2 Nm (0,2 m.kg) Name of the intervention/ Mark Observation of the part Seat Fuel tank cap Rear seat screws and strap Side cover (left and right) Rear seat CAUTION: When removing the cover, be careful...
  • Page 33 INSP COVERS REMOVAL 8 Nm (0,8 m.kg) 3 Nm (0,3 m.kg) 2,5 Nm (0,25 m.kg) 6 Nm (0,6 m.kg) Name of the intervention/ Mark Observation of the part Glove compartment cover Oil cover Side cover (left and right) Rear mudguard CAUTION: When removing the cover, be careful not to damage the mounting clips.
  • Page 34 INSP COVERS REMOVAL 13 Nm (1,3 m.kg) 6,5 Nm (0,65 m.kg) 3 Nm (0,3 m.kg) 6,5 Nm (0,65 m.kg) 2 Nm (0,2 m.kg) Name of the intervention/ Mark Observation of the part Frame reinforcement Fuel tank Rear lower cover Rear light CAUTION: When removing the cover, be careful not to damage the mounting clips.
  • Page 35 INSP COVERS REMOVAL 3 Nm (0,3 m.kg) 3 Nm (0,3 m.kg) 2 Nm (0,2 m.kg) 3 Nm (0,3 m.kg) 3 Nm (0,3 m.kg) Name of the intervention/ Mark Observation of the part Front cover and headlight Front inner cover Front fender Front inner panel CAUTION: When removing the cover, be careful...
  • Page 36: Handlebar Covers

    INSP COVERS HANDLEBAR COVERS 3 Nm (0,3 m.kg) 3 Nm (0,3m.kg) 3 Nm (0,3 m.kg) Name of the intervention/ Mark Observation of the part Handlebar cover (front) Handlebar cover (rear) Meter Flasher light CAUTION: When removing the cover, be careful not to damage the mounting clips.
  • Page 37: Removal

    INSP COVERS REMOVAL 3 Nm (0,3 m.kg) 3 Nm (0,3 m.kg) Name of the intervention/ Mark Observation of the part Battery cover Lower cover CAUTION: When removing the cover, be careful not to damage the mounting clips. For installation,reverse the “REMOVAL”...
  • Page 38 INSP COVERS REMOVAL 4 Nm (0,4 m.kg) 4 Nm (0,4 m.kg) Name of the intervention/ Mark Observation of the part Inner panel Main switch ring. Turn the ring anticlockwise to remove it Footrest board CAUTION: When removing the cover, be careful not to damage the mounting clips.
  • Page 39 INSP COVERS NOTE: Correct routing of cables and wires is essential for a safe operation of this scooter. Refer to the section “CABLE ROUTING” in Chapter 2. NOTE: Be careful not to pinch any wires with the covers. NOTE: When installing the covers, be careful not to damage the mounting clips. 3-10...
  • Page 40: Engine

    INSP ENGINE IDLE SPEED ADJUSTMENT ENGINE ENGINE IDLE SPEED ADJUSTMENT 1. Tighten : • Pilot air screw Turn the pilot air screw in until lightly seated. 2. Loosen : • Pilot air screw Back out from the lightly seated position. Pilot air screw position : DELL'ORTO ±...
  • Page 41: Throttle Cable Free Play Adjustment

    INSP ENGINE IDLE SPEED ADJUSTMENT/ THROTTLE CABLE FREE PLAY ADJUSTEMENT 6. Adjust : • Engine idle speed ******************************************************** Adjustment steps : • Turn the throttle stop screw in or out until specified idling speed is obtained. Turning left Idling speed increased. Turning right Idling speed decreased.
  • Page 42: Spark Plug Inspection

    INSP SPARK PLUG INSPECTION SPARK PLUG INSPECTION 1. Remove : • Spark plug 2. Inspect : • Electrode Q Wear/Damage © Replace. • Insulator W Abnormal color © Replace. Standard spark plug : BR8HS (NGK) 3. Measure : • Plug gap @ Out of specification ©...
  • Page 43: Autolube Pump Air Bleeding

    INSP AUTOLUBE PUMP AIR BLEEDING AUTOLUBE PUMP AIR BLEEDING 1. Bleed : • Pump housing and oil hose ******************************************************* Pump bleeding steps : Place a rag under the pump. Remove the bleed screw . Let oil run until there are no more air bubbles in it.
  • Page 44: Engine Oil Level Inspection

    INSP ENGINE OIL LEVEL INSPECTION ENGINE OIL LEVEL INSPECTION 1. Inspect : • Oil level Oil level low © Add oil to proper level as follows. Q “OIL” indicator light OIL LEVEL AND GAUGE CHECK Turn main switch to " "...
  • Page 45: Transmission Oil Replacement

    INSP TRANSMISSION OIL REPLACEMENT TRANSMISSION OIL REPLACEMENT 1. Remove : • Drain plug Q • Oil filler plug W Drain the transmission oil. 2. Check : • Gasket (drain plug) • O-ring (oil filler plug) Damaged © Replace. 3. Install : •...
  • Page 46: Coolant Level Inspection

    INSP COOLANT LEVEL INSPECTION/ COOLANT REPLACEMENT COOLANT LEVEL INSPECTION NOTE: Install the scooter straight up when inspecting the coolant level. 1.Place the scooter on a level surface. NOTE: Place the scooter on its centerstand. 2.Remove: • Front cover Refer to the section "COVER" 3.Inspect: •...
  • Page 47 INSP COOLANT REPLACEMENT toward the detent. This allows any residual pressure to escape. When the hissing soound has stopped, press down on the cap while turning counterclockwise and remove it. NOTE: Position the scooter straight up when replacing the coolant. 2.Place the scooter on a level surface.
  • Page 48: Air Cleaner Element Cleaning

    INSP AIR CLEANER ELEMENT CLEANING AIR CLEANER ELEMENT CLEANING 1. Remove : • Air cleaner case cover Q 2. Remove : • Air filter element CAUTION: Never operate the engine with the air cleaner element removed. Unfiltered air will cause rapid wear of engine parts and possible engine damage.
  • Page 49: Exhaust Pipe Assembly And Adjustment

    INSP EXHAUST PIPE ASSEMBLY AND ADJUSTMENT MUFFLER Q Exhaust pipe W Cylinder E Crankcase R Bolt T Bolt Y Gasket 4.5 Nm (0.45 m.kg) 29 Nm (2.9 m.kg) 7 Nm (0.7 m.kg) 3-20...
  • Page 50: Chassis

    FRONT BRAKE LEVER FREE PLAY ADJUSTEMENT/ INSP REAR BRAKE LEVER FREE PLAY ADJUSTEMENT/ BRAKE PAD INSPECTION CHASSIS FRONT BRAKE LEVER FREE PLAY ADJUSTMENT 1. Check : • Front brake lever free play @ Out of specification © Adjust. Free play : 10 ~ 20 mm (0.40 ~ 0.80 in) WARNING A soft or spongy feeling in the brake lever can...
  • Page 51: Brake Fluid Level Inspection

    INSP BRAKE FLUID LEVEL INSPECTION BRAKE FLUID LEVEL INSPECTION NOTE: Position the scooter straight up when inspecting the fluid level, and make sure be turning the handlebar that the top of the master cylinder is horizontal. 1. Inspect : • Brake fluid level Brake fluid level is under “LOWER”...
  • Page 52: Air Bleeding (Hydraulic Brake System)

    INSP AIR BLEEDING (HYDRAULIC BRAKE SYSTEM)/ STEERING HEAD ADJUSTEMENT AIR BLEEDING (HYDRAULIC BRAKE SYSTEM) 1. Bleed : • Brake fluid. ******************************************************* Air bleeding steps : a. Add proper brake fluid into the reservoir. b. Install the diaphragm. Be careful not to spill any fluid or allow the reservoir to overflow.
  • Page 53: Tire Inspection

    INSP AIR BLEEDING (HYDRAULIC BRAKE SYSTEM/ STEERING HEAD ADJUSTEMENT Securing nut : 23 Nm (2.3 m.kg) NOTE : Install the torque wrench on the ring nut wrench so that it makes a 90° angle with it. Move the handlebar up and down and from front to rear.
  • Page 54: Wheel Inspection

    INSP TIRE INSPECTION/WHEEL INSPECTION/ CABLE INSPECTION AND LUBRICATION 2 Inspect : • Tire surface Wear/Damage/Cracks/Road hazards © Replace. • Aluminum wheels Damage/Bends © Replace. Never attempt even small repairs to the wheel. WARNING Ride conservatively after installing a tire to allow it to seat itself properly on the rim.
  • Page 55: Lever Lubrication

    CABLE INSPECTION AND LUBRICATION/ INSP FRONT FORK INSPECTION/ REAR SHOCK ABSORBER 2. Check : • Cable movement Stickiness © Lubricate. Recommended lubricant : Engine oil SAE 10W30 NOTE: Hold the cable end up and pour a few drops of oil into the sheath.
  • Page 56: Electrical

    INSP BATTERY INSPECTION ELECTRICAL BATTERY INSPECTION 1. Inspect : UPPER • Battery fluid level LOWER Fluid level low © Add to proper level. Fluid level should be between upper and lower level marks. Q Upper level W Lower level CAUTION: Refill with distilled water only.
  • Page 57: Fuse Inspection

    INSP BATTERY INSPECTION/ FUSE INSPECTION CAUTION: Always charge a new battery before using it to ensure maximum performance. WARNING Battery electrolyte is dangerous. It contains sulfuric acid which is poisonous and highly caustic. Always follow these preventive measures : • Avoid bodily contact with electrolyte as it can cause severe burns and permanent eye injury.
  • Page 58: Headlight Beam Adjustment

    FUSE INSPECTION/ INSP HEADLIGHT BEAM ADJUSTEMENT HEADLIGHT LENS REPLACEMENT ****************************************************** Fuse replacement steps : Turn off the ignition. Install a new fuse of the right amperage. Turn on the switches to verify the operation of the electric circuit. If the fuse immediately blows again, check the electric circuit.
  • Page 59: Headlight Bulb Replacement

    INSP HEADLIGHT LENS REPLACEMENT HEADLIGHT BULB REPLACEMENT HEADLIGHT LENS REPLACEMENT 1. Remove : • Front cover Q 2. Remove : • Headlight lens (Pull out the pins) 3. Remove : • Gasket 4. Install : Reverse the “REMOVAL” procedure. HEADLIGHT BULB REPLACEMENT 1.
  • Page 61: Engine Overhaul

    CHAPTER 4. ENGINE OVERHAUL ENGINE REMOVAL ..................4-1 COVER REMOVAL .................. 4-1 COOLING SYSTEM ................. 4-1 CARBURETOR ..................4-1 CABLES, LEADS AND HOSES ............... 4-2 ENGINE REMOVAL ................. 4-3 ENGINE DISASSEMBLY ................4-4 REAR WHEEL ..................4-4 CENTER STAND ..................4-4 CYLINDER HEAD AND CYLINDER ............
  • Page 62: Engine Removal

    ENGINE REMOVAL ENGINE OVERHAUL ENGINE REMOVAL COVER REMOVAL 1. Remove : • Covers See “CHAPTER 3 - SIDE COVERS AND FOOTREST BOARD - HANDLEBAR COVER”. COOLING SYSTEM 1. Drain: • Coolant CARBURETOR 1. Remove : • Air cleaner case assembly Q 2.
  • Page 63: Cables, Leads And Hoses

    ENGINE REMOVAL 5. Loosen : • Rear wheel fixing bolts 6. Remove: • Rear wheel 7.Loosen: • Rear wheel axle nut 8.Remove: • Rear caliper • Rear wheel collar assembly CABLES, LEADS AND HOSES 1. Remove : • Oil hose on the oil pump side NOTE: Plug the hose to prevent oil spillage.
  • Page 64: Engine Removal

    ENGINE REMOVAL ENGINE REMOVAL 1. Place a suitable stand under the frame. 2. Remove : • Rear shock absorber bolt (lower) Q • Engine mounting bolt W 3. Remove : • Engine NOTE: Lift up the frame and remove the engine. 4.
  • Page 65: Engine Disassembly

    ENGINE DISASSEMBLY ENGINE DISASSEMBLY REAR WHEEL 1. Remove : • Rear wheel Refer to chapter 7 "REAR WHEEL" CENTERSTAND 1. Remove : • Spring • Clip • Plate washer • Axle • Center stand CYLINDER HEAD AND CYLINDER 1. Remove : •...
  • Page 66: Kickstarter

    ENGINE DISASSEMBLY 2. Remove : • Piston pin Q • Piston W • Piston pin bearing E CAUTION: Do not use a hammer to drive out the piston pin. 307002 KICKSTARTER 1. Remove : • Kick crank • Transmission cover Q (left) 313001 2.
  • Page 67: Primary Sheave

    ENGINE DISASSEMBLY PRIMARY SHEAVE 1. Remove : • Oil pump housing 2. Remove : • Nut (primary sheave) NOTE: To loosen the primary sheave nut hold the CDI magneto with a flywheel holder W. Flywheel holder : 90890-01235 3. Remove : •...
  • Page 68: Starter System

    ENGINE DISASSEMBLY 2. Remove : • Clutch housing Q • Secondary sheave W • Crankcase cover gasket • Dowel pins 3. Attach : • Sheave holder Q • Nut wrench (41 mm) 319004 Sheave holder : 90890-01701 4. Loosen : •...
  • Page 69: Transmission

    ENGINE DISASSEMBLY 2. Remove : • Spacer Q • Bearing W • Washer E • Starter motor 317004 TRANSMISSION 1. Remove : • Transmission case Q • Gasket • Dowel pins 319036 2. Remove : • Main shaft Q • Drive shaft W •...
  • Page 70: Autolube Oil Pump

    ENGINE DISASSEMBLY 2. Remove : • Rotor Q • Woodruff key Use the flywheel puller W Flywheel puller : 90890-01189 • Stator assembly 321005 • Gasket AUTOLUBE OIL PUMP 1. Remove : • Autolube oil pump Q 314001 2. Remove : •...
  • Page 71 ENGINE DISASSEMBLY loosen one screw as much as required to level the tool body. 3. Remove : • Crankcase (right) As pressure is applied, keep tapping carefully on the engine mounting bosses. CAUTION: Use a soft hammer to tap on the case. Tap only on reinforced spots of the case.
  • Page 72: Inspection And Repair

    INSPECTION AND REPAIR INSPECTION AND REPAIR CYLINDER HEAD 1. Eliminate : • Carbon deposits Use a rounded scraper Q NOTE: Take care to avoid damaging the spark plug threads. Do not use a sharp instrument. Avoid scratching the aluminum. 2. Inspect : •...
  • Page 73 INSPECTION AND REPAIR 5. Inspect : • Piston wall Wear/Scratches/Damage © Replace. 307004 6. Measure : • Piston to cylinder clearance ******************************************************** Piston to cylinder clearance measurement steps : First step : Measure the cylinder bore “C” with a cylinder bore gauge.
  • Page 74: Piston Rings

    INSPECTION AND REPAIR If out of specification, replace piston and piston rings as a set. 3rd step : Calculate the piston-to-cylinder clearance with following formula: Piston-to cylinder clearance = Cylinder Bore “C” – Piston Skirt Diameter “P” If out of specification, replace cylinder, piston and piston rings as a set.
  • Page 75: Piston Pin And Piston Pin Bearing

    INSPECTION AND REPAIR Standard Limit 0.15 ~ 0.30 mm 0.70 mm ring (0.005 ~ 0.011 in) (0.028 in) 0.15 ~ 0.30 mm 0.70 mm ring (0.005 ~ 0.011 in) (0.028 in) @ Measuring Point 20 mm (0.8 in) PISTON PIN AND PISTON PIN BEARING 1.
  • Page 76: Kick Starter

    INSPECTION AND REPAIR KICK STARTER 1. Inspect : • Kick gear teeth Q • Kick pinion gear teeth W Burrs/Chips/Roughness/Wear © Replace. 317005 2. Inspect : • Mating dogs (kick pinion gear and one-way clutch) Rounded edges/Damage © Replace. 317006 3.
  • Page 77: Autolube Pump

    INSPECTION AND REPAIR AUTOLUBE PUMP Wear or an internal malfunction may cause the pump output to vary from the factory setting. This situation is, however, extremely rare. If improper output is suspected, inspect the following: 1. Inspect : • Delivery line Obstructions ©...
  • Page 78: Secondary Sheave

    INSPECTION AND REPAIR 2. Check : • Free movement Insert the collar W into the primary sliding sheave Q, and check for free movement. Stick or excessive play © Replace the sheave and/or collar. 319007 3. Measure : • Outside diameter Q (weight) Out of specification ©...
  • Page 79: V-Belt

    INSPECTION AND REPAIR 4. Inspect : • Clutch housing inner surface Oil/Scratches © Remove. Use a rag soaked in lacquer thinner or solvent. Use an emery cloth (lightly Scratches and evenly polishing). 319030 5. Measure : • Clutch housing inside diameter @ Out of specification ©...
  • Page 80: Starter Clutch And Gears

    INSPECTION AND REPAIR 2. Measure : • V-belt width @ Out of specification © Replace. V-Belt width : 16,5 mm (0.65 in) <Wear Limit> : 15,7 mm (0.62 in) 312001 STARTER CLUTCH AND GEARS 1. Inspect : • Starter clutch Push the dowel pin in arrow direction.
  • Page 81: Engine Assembly And Adjustment

    ENGINE ASSEMBLY AND ADJUSTMENT CRANKSHAFT AND CRANKCASE Q Oil seal I Crankshaft pin W Oil seal holder O Connecting rod E Crankcase (right) P Crankshaft (left) R Dowel pin { Bearing T Bearing } Engine mount shaft Y Crankshaft (right) q Crankcase (left) U Bearing w Oil seal...
  • Page 82 3. Install : • Dowel pins • Spacer 313005 4. Apply : • HEATPROOF or Yamaha Bond No.1215 To the mating surfaces of both case halves. HEATPROOF or Yamaha Bond No.1215 313006 4-21...
  • Page 83 ENGINE ASSEMBLY AND ADJUSTMENT 5. Attach : • Crankshaft installation tool Q, W, E, R Crankshaft installation tool : Q : 90890-01274 W : 90890-01275 E : 90890-01277 R : 90890-01411 313007 NOTE: Hold the connecting rod at top dead center with one hand while tightening the nut of the installation tool with the other.
  • Page 84 ENGINE ASSEMBLY AND ADJUSTMENT AUTOLUBE PUMP AND CDI MAGNETO Q Nut O Gasket W Plain washer P Oil hose { Oil delivery hose E Rotor assembly R Lighting coil } Clip q Autolube pump T Charge coil Y Pick up coil w O-ring e Circlip U Stator assembly...
  • Page 85: Autolube Pump

    ENGINE ASSEMBLY AND ADJUSTMENT AUTOLUBE PUMP 1. Install : • Circlip Q • Pin W • Pump drive gear E • Circlip R 314004 2. Apply : • Lithium soap base grease (to O-ring ) 3. Install : • Autolube pump Screw (autolube pump) : 4 Nm (0.4 m.kg) 314005...
  • Page 86 ENGINE ASSEMBLY AND ADJUSTMENT 5. Install : • Woodruff key Q • Magneto rotor W • Plain washer E • Nut R NOTE: When installing the magneto rotor, make sure the woodruff key is properly seated in the key 321002 way of the crankshaft.
  • Page 87: Transmission

    ENGINE ASSEMBLY AND ADJUSTMENT TRANSMISSION Q Circlip O Secondary sheave axle W Bearing P Bearing { Dowel pin E Oil seal R Drive axle } Gasket q Transmission case cover T Bearing Y Main axle w Circlips e Oil seal U Conical spring washer I Plain washer 10 Nm (1.0 m.kg)
  • Page 88 ENGINE ASSEMBLY AND ADJUSTMENT TRANSMISSION 1. Apply : • 10W30 Type SE Motor oil (to transmission case cover bearing) 2. Install : • Bearing Q 3. Install : • Oil seal W • Secondary sheave axle E NOTE: Apply lithium soap base grease onto the oil seal lips.
  • Page 89: Starter System

    ENGINE ASSEMBLY AND ADJUSTMENT STARTER SYSTEM Q Collar Y Shaft W Starter wheel gear U Washer E Bearing I Idle gear R Starter clutch O O-Ring T Plate P Starter motor 8 Nm (0.8 m.kg) 13 Nm (1.3 m.kg) 4-28...
  • Page 90 ENGINE ASSEMBLY AND ADJUSTEMENT STARTER SYSTEM 1. Install : • Collar Q • Washer W • Bearing E • Starter wheel gear R • Starter clutch T NOTE: 317010 • Apply lithium soap base grease to the bearing. • Apply molybdenum disulfide oil to the shaft (starter clutch).
  • Page 91: Primary Sheave

    ENGINE ASSEMBLY AND ADJUSTMENT PRIMARY AND SECONDARY SHEAVE Q Nut © } Secondary fixed sheave *Apply BEL-RAY Assembly Lube W Clutch housing q Conical washer E Clutch w One-way clutch R Clutch spring e Special washer T Spring r Primary fixed sheave Y Spring seat t Washer U Oil seal...
  • Page 92 ENGINE ASSEMBLY AND ADJUSTMENT KICK STARTER Y Washer Q Kick shaft U Circlips W Return spring I Kick crank E Collar O Kick clip R Gasket P Rachet T Transmission case 12 Nm (1.2 m.kg) 150 ~ 250 g 10 Nm (1.0 m.kg) 4-31...
  • Page 93: Secondary Sheave

    ENGINE ASSEMBLY AND ADJUSTEMENT SECONDARY SHEAVE When assembling the secondary sheave, reverse the disassembly procedure. Note the following points. 1. Apply : • BEL-RAY Assembly Lube ® (to the sliding parts of the sheave) 319018 2. Install : • Sliding sheave Q NOTE: Wind adhesive tape around the end of the sheave to avoid turning over the oil seal lips when...
  • Page 94 ENGINE ASSEMBLY AND ADJUSTEMENT 8. Install : • Dowel pin • Gasket • Secondary sheave assembly Q • Clutch housing W 319022 9. Tighten : • Nut Q (secondary sheave) Use sheave holder W Sheave holder : P/N. 90890-01701 Nut (secondary sheave) : 30 Nm (3.0 m.kg) 319023 PRIMARY SHEAVE...
  • Page 95 ENGINE ASSEMBLY AND ADJUSTEMENT 5. Install : • V-belt Place the V-belt around the secondary sheave, and compress the secondary sheave spring hard so that the V-belt moves toward the clutch hub. NOTE: • The arrow on the V-belt must point to the front. •...
  • Page 96: Kick Starter

    ENGINE ASSEMBLY AND ADJUSTEMENT 9. Install : • Fan Screw (fan) : 7 Nm (0.7 m.kg) KICK STARTER 1. Install : • Return spring Q • Kick shaft W • Collar E • Washer R • Circlip T 317014 2. Hook : •...
  • Page 97 ENGINE ASSEMBLY AND ADJUSTMENT PISTON, CYLINDER AND CYLINDER HEAD Q Carburetor joint U Cylinder gasket W Reed valve I Piston ring E Gasket O Piston R Cylinder head P Piston pin T Cylinder head gasket { Piston pin clip Y Cylinder } Bearing A Piston clearance: 0.029 ~ 0.042 mm...
  • Page 98: Piston Pin And Piston

    ENGINE ASSEMBLY AND ADJUSTEMENT PISTON PIN AND PISTON 1. Apply : • Engine oil (to crankshaft bearing, connecting rod big end bearing, small end bearing, piston pin, piston ring grooves and piston skirt .) 2. Install : • Small end bearing •...
  • Page 99 ENGINE ASSEMBLY AND ADJUSTEMENT 3. Install : • Cylinder NOTE: Install the cylinder with one hand, while compressing the piston rings with the other hand. 4. Install : • Cylinder head gaskets (new gaskets) 5. Install : • Cylinder head •...
  • Page 100: Engine Remounting

    ENGINE ASSEMBLY AND ADJUSTEMENT 8. Install : • Oil hose • Oil delivery hose ENGINE REMOUNTING Reverse the removal procedure. Note the following points. 1. Install : • Engine mounting bolt 2 • Rear shock absorber bolt 1 (lower) These bolts should be temporarily secured. 2.
  • Page 101: Cooling Sysyem

    ENGINE ASSEMBLY AND ADJUSTEMENT Rear wheel axle nut : 120 Nm (12 m.kg) 8.Install: • Rear wheel 9.Tighten: • Rear wheel fixing bolt Rear wheel fixing bolt: 47 Nm (4.7 m.kg) 10. Install : • Muffler assembly Bolt (muffler) : 26 Nm (2.6 m.kg) Bolt (exhaust pipe) : 9 Nm (0.9 m.kg)
  • Page 102 COOL...
  • Page 103 COOL CHAPTER 5. COOLING SYSTEM RADIATOR ..................... 5-1 REMOVAL ....................5-2 INSPECTION ................... 5-2 INSTALLATION ..................5-2 WATER PUMP ....................5-3 REMOVAL ....................5-4 INSPECTION ................... 5-4 INSTALLATION ..................5-4 THERMOSTATIC VALVE ................5-5 REMOVAL ....................5-6 INSPECTION ................... 5-6 INSTALLATION ..................
  • Page 104: Radiator

    COOL COOLING SYSTEM RADIATOR Q Coolant tank cap U Impeller O-Ring W Coolant tank I Cylinder Head E Radiator O Cylinder R Hose P Thermostatic valve T Water pump { Thermo switch Y O-Ring 7 Nm (0.7 m.kg) 16 Nm (1.6 m.kg)
  • Page 105: Removal

    COOL COOLING SYSTEM COOLING SYSTEM RADIATOR REMOVAL 1.Remove: • Air filter • Carburetor assembly Refer to chepter 6 "CABURETOR" 2.Drain: • Radiator Refer to chapter 3 "COOLANT REPLACEMENT" 3.Remove: • Hose • Radiator assembly. INSPECTION 1.Inspect: • Radiator core Obstruction → Blow out with compressed air through rear of the radiator.
  • Page 106: Water Pump

    COOL COOLING SYSTEM WATER PUMP Q Water pump housing I Bearing W O-Ring O Rotor E Impeller P Circlips R Seal { Rubber T Cover } Driving plug Y Bearing q Washer U Spacer 7 Nm (0.7 m.kg) 6.5 Nm (0.65 m.kg) 6.5 Nm (0.65 m.kg)
  • Page 107: Removal

    COOL COOLING SYSTEM WATER PUMP REMOVAL 1.Remove: • Side cover Refer to chapter 3 "COVER" 2.Drain: • Radiator • Hoses Refer to chapter 3 "COOLANT REPLACEMENT" 3.Remove: • Water pump fixing bolds • Water pump • Hoses INSPECTION 1.Inspect: • Impeller Used/Damaged →...
  • Page 108: Thermostatic Valve

    COOL COOLING SYSTEM THERMOSTATIC VALVE Q Thermostatic switch W Cylinder head E Thermostatic valve R Cylinder 16 Nm (1.6 m.kg)
  • Page 109: Removal

    COOL COOLING SYSTEM THERMOSTATIC VALVE REMOVAL 1.Drain: • Coolant Refer to the chapter 3 "COOLANT REMPLA- CEMENT" 2.Remove: • Cylinder head • Thermostatic valve INSPECTION 1.Inspect: • Thermostatic valve Valve does not open → Replace ******************************************************* Inspection steps: • Suspend thermostatic valve in a vessel. •...
  • Page 110 CARB...
  • Page 111: Carburetion

    CARB CHAPTER 6. CARBURETION CARBURETOR ....................6-1 DELL'ORTO CARBURETOR ..............6-1 REMOVAL ....................6-2 DISASSEMBLY ..................6-2 INSPECTION ................... 6-3 ASSEMBLY ....................6-5 INSTALLATION ..................6-6 FUEL COCK ....................6-7 INSPECTION ................... 6-7 REED VALVE ....................6-7 REMOVAL ....................6-7 INSPECTION ...................
  • Page 112: Carburetor

    CARB CARBURETOR DELL'ORTO CARBURETOR Q Carburetor top P Pilot jet W Gasket { Needle jet E Throttle valve spring } Needle valve R Needle set q Main jet T Throttle valve w Float pin Y Starter plunger spring e Float U Starter plunger r Float chamber gasket I Air screw...
  • Page 113: Removal

    CARB CARBURETOR REMOVAL 1. Remove : • Side covers and footrest board Refer to the section “SIDE COVERS AND FOOTREST BOARD” in Chapter 3. • Air filter case assembly 2.Drain: • Coolant Refer to chapter 3 "COOLANT REPLACEMENT" 3. Disconnect : •...
  • Page 114: Inspection

    CARB CARBURETOR 3. Remove : • Pilot jet Q • Main jet W • Main nozzle E • Starter jet R 322027 4. Remove : • Throttle stop screw Q • Spring (throttle stop screw) • Air screw W • Spring (air screw) 322028 5.
  • Page 115 CARB CARBURETOR 3. Check : • Needle valve Q Wear/Contamination © Replace. • Float W Damage © Replace. • Gasket Damage © Replace. 322013 4. Check : • Throttle valve Q Wear/Damage © Replace. 322014 5. Check : • Throttle valve free movement Unsmooth/stickiness ©...
  • Page 116: Assembly

    CARB CARBURETOR ****************************************************** Float height measurement steps : • Install the needle valve, float and float pin into the carburetor body. • Hold the carburetor upside down. • Measure the height distance between the mating surface of the float chamber (gasket removed) and the top of the float, using a gauge.
  • Page 117: Installation

    CARB CARBURETOR 2. Install : • Throttle valve Q • Starter plunger NOTE: Align the groove W of the throttle valve with the projection E of the carburetor body. 322019 3. Install : • Carburetor NOTE: Align projection Q with projection W. 322020 INSTALLATION To install the carburetor reverse the “REM-...
  • Page 118: Fuel Cock

    FUEL COCK/ FUEL FILTER CLEANING/ CARB REED VALVE FUEL COCK INSPECTION 1. Stop the engine. 2. Remove : • Side covers Refer to the section “SIDE COVERS AND FOOTREST BOARD” in Chapter 3. 3. Check : • Fuel cock ******************************************************** Fuel cock inspection steps : Disconnect the fuel hose.
  • Page 119: Inspection

    CARB REED VALVE 3. Remove : • Carburetor joint • Reed valve assembly INSPECTION 1. Check : • Carburetor joint Damage/Cracks © Replace. • Reed valve Wear/Cracks/Damage © Replace. ********************************************************* Reed valve inspection steps : Visually inspect the reed valve. NOTE: A reed valve in good condition should be completely or at least nearly flush with the valve...
  • Page 120: Installation

    CARB REED VALVE INSTALLATION To install the reed valve reverse the “REM- OVAL” procedure. Note the following points. 1. Install : • Gasket (new) 2. Tighten : • Reed valve assembly bolts Reed valve assembly bolts : 9 Nm (0.9 m.kg) NOTE: Tighten the screws crosswise in several steps to prevent warpage of the read valve assembly and...
  • Page 121 CHAS...
  • Page 122 CHAS CHAPTER 7. CHASSIS FRONT WHEEL ..................... 7-1 REMOVAL ....................7-2 INSPECTION ................... 7-2 INSTALLATION ..................7-3 FRONT BRAKE ....................7-4 BRAKE PAD REPLACEMENT ..............7-6 CALIPER DISASSEMBLY ............... 7-7 MASTER CYLINDER DISASSEMBLY ............. 7-8 INSPECTION AND REPAIR ..............7-9 CALIPER ASSEMBLY ................
  • Page 123: Front Wheel

    CHAS FRONT WHEEL CHASSIS FRONT WHEEL Q Axle Y Tire W Speedometer gear U Valve E Bearing I Collar R Collar O Spacer T Front rim P Nut TIRE SIZE: 130/60 - 13 RIM RUNOUT LIMIT: VERTICAL: 1,0 mm LATERAL: 1,0 mm 35 Nm (3.5 m.kg)
  • Page 124: Removal

    CHAS FRONT WHEEL REMOVAL 1. Remove : • Front caliper fixing bolts • Front caliper • Speedometer cable Q • Axle W • Front wheel NOTE: 340003 Never depress the brake lever when the wheel is off the scooter. Otherwise the brake pads will be forced out.
  • Page 125: Installation

    CHAS FRONT WHEEL INSTALLATION Reverse the “Removal” procedure. Note the following points. 1.Lubricate : • Front wheel axle • Bearings • Oil seal (lips) • Drive/driven gear (speedometer) Recommended lubricant : Lithium soap base grease 2. Install : • Speedometer gear unit Q NOTE: Be sure that the two projections at the gear unit mesh with the two slots on the wheel hub.
  • Page 126: Front Brake

    CHAS FRONT BRAKE FRONT BRAKE NOTE: Q Disk U Pad spring Be sure to install the pads correctly. W Bolt I Pad retainer E Caliper O Brake pads R Piston P O-Ring T Piston seals { Bolt Y Air bleed screw } Mounting bolt A Front brake pad wear limit: 2mm B Front disk wear limit: 3.2 mm...
  • Page 127 CHAS FRONT BRAKE FRONT MASTER CYLINDER Q Master cylinder U Union bolt NOTE: W Master cylinder piston ass'y I Brake hose Drain completely before removing E Diaphragm O Union bolt the master cylinder. R Master cylinder cap P Front brake switch T Master cylinder bracket { Front brake lever Y Copper washer...
  • Page 128: Brake Pad Replacement

    CHAS FRONT BRAKE WARNING • Disc brake components rarely require disassembly. Do not disassemble components unless absolutely necessary. hydraulic connection disconnected, the entire system must be disassembled, drained, cleaned, and then properly filled and bleed after reassembly. Do not use solvents on internal brake component.
  • Page 129: Caliper Disassembly

    CHAS FRONT BRAKE 4. Install : • Brake pads • Pad spring • Axle • Pin NOTE : Be careful to install the brake pads correctly. 5.Lubricate : • Mounting bolt (caliper body) Recommended lubricant : Lithium soap base grease 6.Install : •...
  • Page 130: Master Cylinder Disassembly

    CHAS FRONT BRAKE ******************************************************* Removal steps : Blow compressed air into the hose joint opening to force out the piston from the caliper body. WARNING • Never try to pry out the piston. • Cover the piston with a rag. Use care so that the piston does not cause injury as it is 346004 expelled from the cylinder.
  • Page 131: Inspection And Repair

    CHAS FRONT BRAKE 4. Remove : • Master cylinder dust boot Q • Master cylinder kit W 347008 INSPECTION AND REPAIR Recommended brake component replacement schedule : Brake pads As required Piston seal, Every two years Dust seal Brake hoses Every four years Replace only...
  • Page 132: Caliper Assembly

    CHAS FRONT BRAKE 3. Check : • Brake hose Q Cracks/Wear/Damage © Replace. 346014 4. Measure : • Brake disc deflection Out of specification © Inspect wheel runout. If wheel runout is good, replace the brake disc(s). Maximum deflection : 0.25 mm (0.01 in) 347001 •...
  • Page 133: Master Cylinder Assembly

    CHAS FRONT BRAKE 2. Install : • Brake caliper Apply LOCTITE LOCTITE ® Bolt (brake caliper) : 23 Nm (2.3 m.kg) 3. Install : • Caliper body Q 4. Install : • Brake hose W • Copper washers E • Union bolt R 346005 Union bolt : 23 Nm (2.3 m.kg)
  • Page 134 CHAS FRONT BRAKE 1. Install : • Master cylinder Q CAUTION: • Install the master cylinder holder with the arrow mark pointing upwards. • Tighten the upper bolt first, then the lower bolt. 347010 Bolt (master cylinder holder) : 1.1 Nm (0.11 m.kg) 2.
  • Page 135: Rear Wheel

    CHAS REAR WHEEL REAR WHEEL Q Cover plug Y Valve W Nut U Rear rim E Washer I Distance collar R Bolt O Rear brake disk T Rear wheel tire TIRE SIZE: 140/60 - 13 RIM RUNOUT LIMIT: VERTICAL: 1,0 mm LATERAL: 1,0 mm 120 Nm (12.0 m.kg)
  • Page 136: Rear Master Cylinder

    CHAS REAR WHEEL REAR MASTER CYLINDER NOTE: Q Master cylinder U Union bolt Drain completely before removing W Master cylinder piston ass'y I Brake hose the master cylinder. E Diaphragm O Union bolt R Master cylinder cap P Rear brake switch T Master cylinder bracket { Rear brake lever Y Copper washer...
  • Page 137: Removal

    CHAS REAR WHEEL WARNING • Disc brake components rarely require disassembly. disassemble components unless absolutely necessary. If any hydraulic connection is disconnected, the entire system must be disassembled, drained, cleaned, and then properly filled and bled after reassembly. Do not use solvents on internal brake component.
  • Page 138: Installation

    CHAS REAR WHEEL 3. Check : • Wheel bearings Refer to the section “FRONT WHEEL INSPECTION”. REAR BRAKE For removal, inspection and assembly refer to the section "FRONT BRAKE" INSTALLATION Reverse the REMOVAL procedure. Note the following points. 1.Install • Rear wheel 2.
  • Page 139: Front Fork

    CHAS FRONT FORK FRONT FORK Q Steering bracket P Spring W Bolt { Spacer E Circlip } Plunger R Rubber cap q Dust boot T Circlip w Retainer Y Spring seat e Oil seal U O-Ring r Outer fork tube I Spring t Washer O Piston...
  • Page 140: Removal

    CHAS FRONT FORK REMOVAL WARNING Securely support the scooter with a stand under the engine. 1. Place the scooter on an even surface. 2. Disconnect : • Speedometer cable 3. Remove : • Front wheel Refer to section “FRONT WHEEL” in Chapter 7. 4.
  • Page 141: Disassembly

    CHAS FRONT FORK DISASSEMBLY 1. Remove : • Rubber plug Q • Circlip W • Spring seat E • Spring R 342014 2. Remove : • Bolt Q • Copper washer NOTE: To remove the drain bolt Q, use the T-handle W and the holder E.
  • Page 142: Inspection

    CHAS FRONT FORK INSPECTION 1. Check : • Inner fork tube and fork components • Outer fork tube Wear/Scratches/Damage © Replace. WARNING Never attempt to straighten a bent fork tube as this may dangerously weaken the tube. 2. Measure : •...
  • Page 143: Installation

    CHAS FRONT FORK 3. Install : • Copper washer • Bolt NOTE: Tighten the drain bolt Q while holding the piston with the T-handle W and holder E. T-handle for front fork : 342010 90890-01326 Holder : 90890-01294 4. Fill : •...
  • Page 144: Steering Head And Handlebar

    CHAS STEERING HEAD AND HANDLEBAR STEERING HEAD AND HANDLEBAR Q Handlebar W Nut E Bolt R Trottle grip T Throttle cable Y Starter cable (Choke) 60 Nm (6.0 m.kg) 7-22...
  • Page 145: Removal

    CHAS STEERING HEAD AND HANDLEBAR STEERING HEAD AND HANDLEBAR REMOVAL WARNING Securely support the scooter so there is no danger of it falling over. 1. Place the scooter on an even surface. 2. Remove : • Front fender • Inner panels •...
  • Page 146: Inspection

    CHAS STEERING HEAD AND HANDLEBAR 11. Remove : • Upper bearing race Q Ring nut wrench : 9079Q-02218 • Steering shaft • Bearing balls 354005 INSPECTION 1. Check : • Handlebar Q Bends/Cracks/Damage © Replace. 2. Wash the bearing balls in solvent. 3.
  • Page 147: Assembly And Installation

    CHAS STEERING HEAD AND HANDLEBAR CAUTION: • Unless installed correctly, the bearing races will damage the frame. • Never hit the bearing races on the ball race surface. ********************************************************* 354008 4. Check : • Steering shaft Bend/Damage © Replace. WARNING Never attempt to straighten a bent steering shaft.
  • Page 148 CHAS STEERING HEAD AND HANDLEBAR CAUTION: Hold the steering shaft until it is securely attached. 4. Install : • Washer Q • Steering shaft lock nut W NOTE: 354002 Tighten the steering shaft lock nut with the ring nut wrench. Set the torque wrench to the ring nut wrench so that they form a right angle.
  • Page 149 ELEC...
  • Page 150: Electrical

    ELEC CHAPTER 8. ELECTRICAL COMPONENTS ELECTRICAL COMPONENTS ..............8-1 CIRCUIT DIAGRAM ..................8-3 IGNITION AND STARTING SYSTEM ............8-5 CIRCUIT DIAGRAM ................. 8-5 IGNITION AND STARTING SYSTEM CIRCUIT DIAGRAM ....8-6 TROUBLESHOOTING ................8-7 CHARGING SYSTEM .................. 8-13 CIRCUIT DIAGRAM ................8-13 TROUBLESHOOTING ................
  • Page 151: Electrical Components

    ELEC ELECTRICAL SYSTEM ELECTRICAL SYSTEM ELECTRICAL COMPONENTS Q Wire harness W Fuel sender E Starter relay R Ignition coil T CDI unit Y Oil sender U Battery I Resistance...
  • Page 152 ELEC ELECTRICAL SYSTEM ELECTRICAL COMPONENTS Q Main switch W Flasher relay E Horn R Rectifier/Regulator...
  • Page 153: Circuit Diagram

    ELEC CIRCUIT DIAGRAM CIRCUIT DIAGRAM Br Gy LOCK LOCK CHECK CHECK Br Gy YB LR L r r r Br/W Br/W Dg Ch Br/W HI HI...
  • Page 154 ELEC CIRCUIT DIAGRAM Q Spark plug u Rear stop switch W Ignition coil i Flasher relay E CDI magneto o Flasher switch R CDI unit p Flasher indicator T Rectifier/regulator [ Rear flasher light (Left) Y Dimmer switch ] Front flasher light (Left) U Starter motor A Front flasher light (Right) I Starter relay...
  • Page 155: Ignition And Starting System

    ELEC IGNITION AND STARTING SYSTEM IGNITION AND STARTING SYSTEM Br Br Gy LOCK LOCK CHECK CHECK Br Gy YB LR LR L r r r Br/W Br/W Dg Ch Br/W HI HI Spark plug Fuse Ignition coil Battery CDI magneto Starter switch CDI unit Main switch...
  • Page 156: Ignition And Starting System Circuit Diagram

    ELEC IGNITION AND STARTING SYSTEM IGNITION AND STARTING SYSTEM CIRCUIT DIAGRAM Q Spark plug } Main switch Source coil W Ignition coil t Front brake switch Pickup coil R CDI unit y Rear brake switch Wave-shape shaping circuit U Starter Motor Condenser I Starter relay Diode...
  • Page 157: Troubleshooting

    ELEC IGNITION AND STARTING SYSTEM TROUBLESHOOTING THE STARTING SYSTEM DOES NOT WORK (NO SPARK OR IRREGULAR SPARKS). NOTE : • Remove the following parts before proceeding with the troubleshooting : 1) Side covers (left and right) • For accurate troubleshooting use the following special tools : Ignition checker : Pocket tester : 90890-06754...
  • Page 158 ELEC IGNITION AND STARTING SYSTEM 3.Spark plug cap resistance • Disconnect the spark plug cap. • Connect the pocket tester (Ω x 1 k) to the spark plug cap. • Check the resistance of the spark plug cap. Spark plug cap resistance : Ω...
  • Page 159 ELEC IGNITION AND STARTING SYSTEM 5.Pickup coil resistance • Disconnect the pickup coil coupler. MAGNETO • Connect the pocket tester (Ω x 100) to the pickup coil. Pocket tester (+) lead Q © White / Red W/R B/R Pocket tester (-) lead W © Ground •...
  • Page 160 ELEC IGNITION AND STARTING SYSTEM TROUBLESHOOTING STARTER MOTOR DOES NOT WORK NOTE : • Remove the following parts before proceeding with the troubleshooting: 1) Side covers (left and right) 2) Footrest boards 3) Front panel 4) Handlebar cover • For accurate troubleshooting use the following special tools: Pocket tester : 90890-03112 1.Fuse...
  • Page 161 ELEC IGNITION AND STARTING SYSTEM 4. Starter relay • Disconnect the Blue/White lead from the wire harness. • Connect the (-) Q terminal of the battery to the Blue/White lead. • Check the starter motor operation. DOES NOT WORK Starter relay defect © Replace. WORKS 5.
  • Page 162 ELEC IGNITION AND STARTING SYSTEM LW B DOES NOT MEET SPECIFICATION YB L Starter switch defect © Replace right handle- bar switch. MEETS SPECIFICATION POOR CONNECTIONS 7.Connections Check all connections in the starter system. Refer to “WIRING DIAGRAM”. Repair. 8-12...
  • Page 163: Charging System

    ELEC CHARGING SYSTEM CHARGING SYSTEM WIRING DIAGRAM Br Br Gy LOCK CHECK Br Gy YB LR L r r r Br/W Br/W Dg Ch Br/W CDI magneto Rectifier/regulator Fuse Battery 8-13...
  • Page 164 ELEC CHARGING SYSTEM TROUBLESHOOTING THE BATTERY IS NOT CHARGED NOTE : • Remove the following parts before proceeding with the troubleshooting : 1) Side covers (left and right) and foot rest board. • For accurate troubleshooting use the following special tools : Inductive tachometer : Pocket tester : 90890-03113...
  • Page 165 ELEC CHARGING SYSTEM 4.Charging coil resistance • Disconnect the CDI magneto coupler from MAGNETO the wire harness. • Connect the pocket tester (Ω x 1) to the charging coil. • Check the charging coil resistance W/R B/R Tester (+) lead © White Q Tester (–) lead ©...
  • Page 166: Circuit Diagram

    ELEC LIGHTING SYSTEM LIGHTING SYSTEM CIRCUIT DIAGRAM Br Gy LOCK CHECK Br Gy YB LR L r r r Br/W Ch Br/W Dg CDI magneto Meter light Dimmer switch Tail/Stop light Lighting switch Position light “HIGH BEAM indicator” Resistor Head light 8-16...
  • Page 167: Troubleshooting

    ELEC LIGHTING SYSTEM TROUBLESHOOTING THE AUXILIARY LIGHT, HEADLIGHT, HEADLIGHT INDICATOR, TAIL LIGHT OR METER LIGHT DO NOT WORK NOTE : Remove the following parts before proceeding with the troubleshooting : • Side covers and footrest board • Handlebar covers For accurate troubleshooting use the following special tools : Pocket tester : 90890-03112 1.
  • Page 168 ELEC LIGHTING SYSTEM 3. Lighting coil resistance • Disconnect the lighting coil coupler from the MAGNETO wire harness. • Connect the pocket tester (Ω x 1) to the lighting coil. • Check the lighting coil resistance W/R B/R Tester (+) lead © Yellow / Red Q Tester (-) lead ©...
  • Page 169 ELEC LIGHTING SYSTEM LIGHTING SYSTEM INSPECTION 1. Headlight and headlight indicator do not work. 1. Bulb and socket NO CONTINUITY • Check the bulb and socket for continuity. Replace bulb or socket. CONTINUITY 2. Voltage • Connect the pocket tester (AC20V) to the headlight coupler.
  • Page 170 ELEC LIGHTING SYSTEM 2. Voltage • Connect the pocket tester (AC20V) to the meter light coupler. Pocket tester (+) lead © Blue / Red Q Pocket tester (-) lead © Black W • Set the main switch to “ON”. • Start the engine. •...
  • Page 171: Signal System

    ELEC SIGNAL SYSTEM SIGNAL SYSTEM WIRING DIAGRAM Br Br Gy LOCK LOCK CHECK CHECK Br Gy YB LR LR L r r r Br/W Ch Br/W Dg HI HI Fuse Rear flasher light (Right) Battery Horn Main switch Horn switch Tail/Stop light Oil lever indicator Flasher relay...
  • Page 172: Troubleshooting

    ELEC SIGNAL SYSTEM TROUBLESHOOTING FLASHER LIGHTS, TAIL/BRAKE LIGHT, “OIL” WARNING LIGHT DOES NOT WORK HORN DOES NOT SOUND, FUEL METER DOES NOT WORK NOTE : Remove the following parts before proceeding with the troubleshooting: • Side covers and footrest board •...
  • Page 173 ELEC SIGNAL SYSTEM 4. Connections POOR CONNECTIONS • Check all connections in the signal system. Refer to “WIRING DIAGRAM”. GOOD Repair. CONNECTIONS Check the condition of each circuit of the signal system. Refer to the section “SIGNAL SYSTEM CHECK”. SIGNAL SYSTEM CHECK 1.
  • Page 174 ELEC SIGNAL SYSTEM DOES NOT MEET SPECIFICATION Defect in the wire harness between the main switch and the horn © Repair. MEETS SPECIFICATION 3. Horn • Disconnect the “Pink” lead at the horn terminal. • Ground the horn terminal Q with a jumper lead.
  • Page 175 ELEC SIGNAL SYSTEM 2. The tail light does not work. 1. Bulb and socket NO CONTINUITY • Check the bulb and socket for continuity. CONTINUITY Replace bulb or socket. 2. Brake switch • Disconnect the brake switch leads from the wire harness.
  • Page 176 ELEC SIGNAL SYSTEM 3. Flasher does not work NO CONTINUITY 1. Bulb and socket • Check the bulb and socket for continuity. Replace bulb or socket. CONTINUITY 2. “TURN” switch • Disconnect the handlebar switch (left) from the wire harness. •...
  • Page 177 ELEC SIGNAL SYSTEM 4. Voltage • Connect the pocket tester (DC20V) to the flasher relay. Pocket tester (+) lead © Brown / White Q Pocket tester (-) lead © Ground • Turn the main switch to “ON”. • Check the voltage (12V) between Brown / White and the ground.
  • Page 178 ELEC SIGNAL SYSTEM This circuit is in good condition. 4. The “OIL” indicator light does not work. 1. Bulb and socket NO CONTINUITY • Check the bulb and socket for continuity. CONTINUITY Replace bulb or socket. 2. Oil level switch •...
  • Page 179 ELEC SIGNAL SYSTEM 3. Voltage • Connect the pocket tester (DC20V) to the bulb socket connector. Pocket tester (+) lead © Grey Q Pocket tester (-) lead © Ground • Turn the main switch to ON. • Check the voltage (12V) between “Grey” and the ground.
  • Page 180: Cooling System

    ELEC COOLING SYSTEM COOLING SYSTEM WIRING DIAGRAM Br Br Gy LOCK LOCK CHECK CHECK Br Gy YB LR LR L r r r Br/W Ch Br/W Br/W Dg HI HI Fuse Battery Main switch Water temperature indicator Water sender 8-30...
  • Page 181 ELEC COOLING SYSTEM TROUBLESHOOTING WATER TEMPERATURE METER DOES NOT MOVE, WHEN THE ENGINE IS WARM. NOTE : Remove the following parts before proceeding with the troubleshooting: • Side covers and footrest board • Handlebar cover For accurate troubleshooting use the following special tools : Pocket tester : 90890-03112 1.
  • Page 182 ELEC COOLING SYSTEM 4. Thermo unit • Remove the thermo unit from the head cylinder. • Connect the pocket tester (Ω x100) then (Ω x 10) to the thermo unit • Immerse the thermo unit in the water. • Measure the resistance. Thermo unit resistance: °...
  • Page 183 TRBL SHTG...
  • Page 184: Troubleshooting

    TRBL SHTG CHAPTER 9. TROUBLESHOOTING STARTING FAILURE/ HARD STARTING ............. 9-1 FUEL SYSTEM ..................9-1 ELECTRICAL SYSTEM ................9-1 COMPRESSION SYSTEM ..............9-2 POOR IDLE SPEED PERFORMANCE ............9-2 POOR IDLE SPEED PERFORMANCE ........... 9-2 POOR MEDIUM AND HIGH SPEED PERFORMANCE ........ 9-3 FUEL SYSTEM ..................
  • Page 185: Starting Failure/Hard Starting

    TRBL SHTG STARTING FAILURE/HARD STARTING TROUBLESHOOTING NOTE: 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 inspection, adjustment and replacement of parts. STARTING FAILURE/HARD STARTING FUEL SYSTEM Fuel tank...
  • Page 186: Compression System

    TRBL STARTING FAILURE/HARD STARTING/ SHTG POOR IDLE SPEED PERFORMANCE COMPRESSION SYSTEM Cylinder and cylinder head Crankcase and crankshaft • Loose spark plug • Improperly seated crankcase • Loose cylinder head or cylinder • Improperly sealed crankcase • Broken cylinder head gasket (damaged oil seal) •...
  • Page 187: Poor Medium And High Speed Performance

    TRBL POOR MEDIUM AND HIGH SPEED PERFORMANCE/ FAULTY AUTOMATIC SHTG POOR MEDIUM AND HIGH SPEED PERFORMANCE FUEL SYSTEM Fuel tank Carburetor • Clogged fuel filter • Deteriorated fuel, fuel containing water or • Deteriorated fuel or fuel containing water or foreign material foreign material •...
  • Page 188: Poor Standing Start (Low Climbing Ability)

    TRBL FAULTY AUTOMATIC/ SHTG OVER HEATING OR OVER-COOLING POOR STANDING START (LOW CLIMBING ABILITY) V-belt Secondary sheave • Worn, damaged or slipped v-belt • Fatigued compression spring Primary sheave • Improper operation of secondary sliding sheave • Worn or improper operation of weight POOR ACCELERATION (POOR HIGH SPEED) V-belt •...
  • Page 189: Improper Kicking

    TRBL IMPROPER KICKING/ SHTG FAULTY BRAKE IMPROPER KICKING SLIPPING Kick axle assembly Transmission oil • Low tension of kick clip • Improper quality (low viscosity) • Worn kick axle • Deterioration • Worn or damaged kick gear • Damaged kick clip •...
  • Page 190: Instable Handling

    FRONT FORK OIL LEAKAGE AND FRONT FORK TRBL MALFUNCTION/ SHTG INSTABLE HANDLING FRONT FORK OIL LEAKAGE AND FRONT FORK MALFUNCTION OIL LEAKAGE MALFUNCTION • Bent, damaged or rusty inner tube • Bent, deformed or damaged inner tube • Damaged or cracked outer tube •...
  • Page 191: Faulty Signal And Lighting System

    TRBL SHTG FAULTY SIGNAL AND LIGHTING SYSTEM FAULTY SIGNAL AND LIGHTING SYSTEM Headlight dark Flasher does not light • Improper bulb • Improperly grounded • Too many electric accessories • Discharged battery • Hard charging (broken charging coil) • Faulty flasher switch •...
  • Page 192 Q Handlebar switch (right) YQ50 WIRING DIAGRAM W ”START“ switch E ”LIGHT“ switch Meter with tachometer R Resistor T Main switch Y Ignition coil YB LR L LOCK U Spark plug LW B CHECK I Rectifier / regulator - - - -...

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