Yamaha YP250 Service Manual
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Yamaha YP250 Service Manual

Motorcycle yp250 4uc-ae1
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  • Page 3 EB000000 YP250 SERVICE MANUAL 1996 by Yamaha Motor Co., Ltd. 1st Edition, January 1996 All rights reserved. Any reprinting or unauthorized use without the written permission of Yamaha Motor Co., Ltd. is expressly prohibited.
  • Page 4 It is not possible to include all the knowledge of a mechanic in one manual, so it is assumed that anyone who uses this book to perform maintenance and repairs on Yamaha scooter has a basic understanding of the mechanical ideas and the procedures of scooter repair. Re- pairs attempted by anyone without this knowledge are likely to render the scooter unsafe and unfit for use.

  • Page 5: How To Use This Manual

    YP002000 HOW TO USE THIS MANUAL MANUAL ORGANIZATION This manual consists of chapters for the main categories of subjects. (See “Illustrated symbols”) 1st title 1 : This is the title of the chapter with its symbol on the upper right corner of each page. 2nd title 2 : This title indicates the section of the chapter and only appears on the first page of each section.

  • Page 6: Periodic Inspection And

    EB003000 ILLUSTRATED SYMBOLS Illustrated symbols 1 to 9 are designed as thumb tabs to indicate the chapter’s number and content. 1 General information 2 Specifications 3 Periodic inspection and adjustment 4 Engine 5 Cooling system 6 Carburetion 7 Chassis 8 Electrical 9 Troubleshooting Illustrated symbols are used to identify...
  • Page 7 INDEX GENERAL INFORMATION INFO SPECIFICATIONS SPEC PERIODIC INSPECTION AND INSP ADJUSTMENT ENGINE OVERHAUL COOLING SYSTEM COOL CARBURETION CARB CHASSIS CHAS ELECTRICAL ELEC TROUBLESHOOTING TRBL SHTG...

  • Page 9: Table Of Contents

    CHAPTER 1 GENERAL INFORMATION SCOOTER IDENTIFICATION ........VEHICLE IDENTIFICATION NUMBER (for E) .

  • Page 11: General Information Scooter Identification

    SCOOTER IDENTIFICATION INFO YP100000 GENERAL INFORMATION SCOOTER IDENTIFICATION YP100010 VEHICLE IDENTIFICATION NUMBER (for E) The vehicle identification number 1 is stamped into the right side of the frame. NOTE: The vehicle identification number is used to identify your scooter and may be used to regis- ter your scooter with the licensing authority in your country.

  • Page 12: Features

    FEATURES INFO FEATURES OIL INDICATOR LIGHT S Function Pulses (travel distance signals) from the speedometer are counted and cause the oil indicator light to come on at 1,000 km for the first time and thereafter every 3,000 km. In this way, this light indicates the time for oil change.

  • Page 13: Auto Choke System

    FEATURES INFO AUTO-CHOKE SYSTEM This system is the parallel connection of the ignitor unit circuit and the thermo switch as shown, detect- ing the engine temperature, and facilitates the restarting with the warm engine. S Circuit diagram Igniter unit Main switch Thermo Fuse Ignition...

  • Page 14: Important Information

    6. Keep all parts away from any source of fire. EB101010 REPLACEMENT PARTS 1. Use only genuine Yamaha parts for all re- placements. Use oil and grease recom- mended by Yamaha for all lubrication jobs. Other brands may be similar in function and appearance, but inferior in quality.

  • Page 15: Lock Washers/Plates And Cotter Pins

    IMPORTANT INFORMATION INFO EB101030 LOCK WASHERS/PLATES AND COTTER PINS 1. Replace all lock washers/plates and cotter pins after removal. Bend lock tabs along the bolt or nut flats after the bolt or nut has been tightened to specification. EB101040 BEARINGS AND OIL SEALS Install bearings and oil seals so that the manufacturer’s marks or numbers are visible.

  • Page 16: Checking Of Connections

    IMPORTANT INFORMATION INFO EB801000 CHECKING OF CONNECTIONS Dealing with stains, rust, moisture, etc. on the connector. 1. Disconnect: S Connector 2. Dry each terminal with an air blower. 3. Connect and disconnect the connector two or three. 4. Pull the lead to check that it will not come off.

  • Page 17: How To Use The Conversion Table

    HOW TO USE THE CONVERSION TABLE INFO EB201000 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. METRIC MULTIPLIER **mm 0.03937...

  • Page 18: 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 inappropri- ate tools or improvised techniques. When placing an order, refer to the list provided below to avoid any mistakes.
  • Page 19 SPECIAL TOOLS INFO Tool No. Tool name/Usage Illustration 90890-01362 Flywheel puller This tool is used for removing the rotor. 90890-01367 Fork seal driver weight -01368 Fork seal driver attachment (ø33) This tool is used when installing the fork seal. 90890-01384 Oil seal guide This tool is used for protecting the oil seal lip when installing the secondary...
  • Page 20 Mechanical seal installer These tools are used for installing mechanical seal. 90890-06754 Ignition checker This instrument is necessary for checking the ignition system components. 90890-85505 Yamaha bond No. 1215 This sealant (bond) is used for crankcase mating surface, etc. 1-10...
  • Page 21 CHAPTER 2. SPECIFICATIONS GENERAL SPECIFICATIONS ........MAINTENANCE SPECIFICATIONS .

  • Page 23: Chapter 2. Specifications

    SPEC GENERAL SPECIFICATIONS SPECIFICATIONS GENERAL SPECIFICATIONS Model YP250 Model code: 4UC 1 (except for CH, A) 4UD1 (for CH, A) Dimensions: Overall length 2,110 mm Overall width ,750 mm Overall height 1,330 mm Seat height ,700 mm Wheelbase 1,500 mm...
  • Page 24 SPEC GENERAL SPECIFICATIONS Model YP250 Carburetor: Type/quantity Y28V-1A/1 Manufacturer TEIKEI Spark plug: Type DR8EA Manufacturer 0.6 X 0.7 mm Spark plug gap Clutch type: Dry, centrifugal automatic Transmission: Primary reduction system Helical gear Primary reduction ratio 40/15 (2.666) Secondary reduction sytem...
  • Page 25 SPEC GENERAL SPECIFICATIONS Model YP250 Brake: Front brake type Single disc brake operation Right hand operation Rear brake type Drum brake operation Left hand operation Suspension: Front suspension Telescopic fork Rear suspension Unit swing Shock absorber: Front shock absorber Coil spring/Oil damper...

  • Page 26: Maintenance Specifications

    SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Item Standard Limit Cylinder head: Warp limit 0.03 mm Cylinder: 69.000 X 69.005 mm Bore size 69.1 mm Out of round limit 0.03 mm Camshaft: Cam dimensions 36.545 X 36.645 mm Intake “A” 36.45 mm 30.021 X 30.121 mm “B”...
  • Page 27 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit 0.010 X 0.037 mm Stem-to-guide clearance 0.08 mm 0.025 X 0.052 mm 0.1 mm Stem runout limit 0.01 mm 0.9 X 1.1 mm Valve seat width 1.6 mm 0.9 X 1.1 mm 1.6 mm Valve spring: Free length (Inner) IN/EX...
  • Page 28 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Automatic centrifugal clutch: Clutch shoe thickness 3.0 mm 2.0 mm Clutch housing inside diameter 135 mm 135.5 mm Clutch shoe spring free length 28.1 mm Weight outside diameter 20 mm 19.5 mm 2,100 X 2,700 r/min Clutch –...
  • Page 29 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Radiator: Type Cooling fin with electric fan Width/height/thickness 140/238/24 mm 110 X 140 kPa (1.1 X 1.4 kg/cm Radiator cap opening pressure 1.1 X 1.4 bar) Radiator capacity 1.4 L Reservoir tank capacity 0.35 L Thermostatic valve: Type/manufacturer 4HC/NIHON THERMOSTAT...
  • Page 30 SPEC MAINTENANCE SPECIFICATIONS TIGHTENING TORQUES ENGINE Tightening Thread torque Part to be tightened Part name Q’ty Remarks size size mSkg Oil check bolt — Exhaust pipe stud bolt — Spark plug — Cam sprocket cover Bolt Cylinder head and cylinder Cylinder head and cylinder Bolt (Cam chain side)
  • Page 31 SPEC MAINTENANCE SPECIFICATIONS Tightening Thread torque Part to be tightened Part name Q’ty Remarks size size mSkg Cover (oil pump) Bolt Timing check plug Plug One way clutch — Clutch housing Bolt Grease stopper (Primary sheave) — Primary fixed sheave —...

  • Page 32: Chassis

    SPEC MAINTENANCE SPECIFICATIONS CHASSIS Item Standard Limit Steering system: Steering bearing type Ball bearing Front suspension: Front fork travel 100 mm Fork spring free length 265.8 mm 263.5 mm Spring rate (K1) 5.7 N/mm (0.57 kg/mm) 0 X 100 mm Stroke (K1) Oil capacity...
  • Page 33 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Rear drum brake: Type Leading, trailing Drum inside diameter 160 mm 161 mm Shoe thickness 4 mm 2 mm Brake lever: 2 X 5 mm Brake lever free play (front at lever side) 10 X 20 mm Brake lever free play (rear) 3 X 5 mm Throttle cable free play...
  • Page 34 SPEC MAINTENANCE SPECIFICATIONS TIGHTENING TORQUES CHASSIS Tightening torque Part to be tightened Thread size Remarks mSkg Frame and engine bracket 1.25 Engine bracket, compression rod and engine 1.25 Compression rod and frame 1.25 Sidestand (bolt and frame) 1.25 Sidestand (bolt and nut) 1.25 Rear footrest bracket Swingarm...
  • Page 35 SPEC MAINTENANCE SPECIFICATIONS NOTE: 1. First, tighten the ring nut (lower) approximately 38 Nm (3.8 mSkg) by using the torque wrench, then loosen the ring nut 1/4 turn. 2. Second, tighten the ring nut (lower) approximately 22 Nm (2.2 mSkg) by using the torque wrench, then finger tighten the ring nut (center).

  • Page 36: Electrical

    SPEC MAINTENANCE SPECIFICATIONS ELECTRICAL Item Standard limit Ignition timing: Ignition timing (B.T.D.C.) 10_ at 1,500 r/min Advanced timing (B.T.D.C.) 32_ at 5,000 r/min Advanced type Electrical type T.C.I.: 168 X 252 Pickup coil resistance/color at 20_C/ Yellow – Black T.C.I. unit model/manufacturer J4T069/MITSUBISHI Ignition coil: Model/manufacturer...
  • Page 37 SPEC MAINTENANCE SPECIFICATIONS Item Standard limit Starter relay: Model/manufacturer 4FL/JIDECO Amperage rating 100 A 4.2 X 4.6 Coil winding resistance at 20_C Horn: Model/manufacturer YF-12/NIKKO Maximum amperage 2.5 A Flasher relay: Type Full transistor type Model/manufacturer 4MY/NIPPONDENSO 75 X 95 cycle/min Flasher frequency Fuel gage: Model/manufacturer...

  • Page 38: General Torque Specifications

    SPEC GENERAL TORQUE SPECIFICATIONS GENERAL TORQUE SPECIFICATIONS This chart specifies torque for standard fasten- General torque ers with standard I.S.O. pitch threads. Torque specifications (Nut) (Nut) (Bolt) (Bolt) specifications for special components or as- mSkg semblies are included in the applicable sections 10 mm 6 mm of this book.

  • Page 39: Lubrication Point And Grade Of Lubricant

    Idle gear 1 thrust surfaces Shaft 1 Idle gear 2 thrust surfaces Idle gear 2 inner surface Main axle thrust surfaces Crankcase mating surfaces Yamaha bond No. 1215 Crankcase breather plug Stator grommet Yamaha bond No. 1215 Suction pipe 2-17...

  • Page 40: Chassis

    SPEC LUBRICATION POINT AND GRADE OF LUBRICANT CHASSIS Lubrication Point Symbol Front wheel oil seal lips (left/right) Swingarm oil seal lips (left/right) Steering head pipe bearing (upper/lower) Steering head pipe dust seal lips (upper/lower) Tube guide (throttle grip) inner surface Brake cable (brake lever) Brake lever and lever holder bolt sliding surface Sidestand sliding surface...

  • Page 41: Cable Routing

    SPEC CABLE ROUTING CABLE ROUTING Rectifier regulator Battery negative (–) lead B Pass the seat lock cable Fuel sender Flasher relay through the protection pipe. Fuse (fan) Reservoir tank C Clamp the mainharness and Roll over valve Breather hose radiator over flow hose Ignition coil Air filter together to the frame.
  • Page 42 SPEC CABLE ROUTING E Pass the overflow hose from J Keep the clamping clearance the reservoir tank through the over 5 mm. clamp inside the frame. (Bend the metal clamp to keep F Clamp the mainharness, battery the clearance between the (+) lead and (–) lead to clamp metal clamp and link over of the frame.
  • Page 43 SPEC CABLE ROUTING Seat lock A Clamp the mainharness and H Clamp the mainharness, A.C. Air filter case sidestand switch lead magneto lead, starter motor Breather hose together the frame. lead and engine earth lead Fuel hose B Clamp the sidestand switch together inside the frame.
  • Page 44 SPEC CABLE ROUTING Front flasher light (right) Brake hose stopper D Do not interfere each other Front flasher light (left) Marking after installing the handlebar Handlebar switch (right) lead upper cover. Front brake switch lead A Clamp the speedometer lead E Pass the handlebar switch Seat lock cable the stay 1.
  • Page 45 SPEC CABLE ROUTING G Pass the brake hose through the hose holder and clamp. H Clamp the headlight lead and horn lead from mainharness to the stay 1. I Install the brake hose with its marking facing to the stopper side.
  • Page 46 SPEC CABLE ROUTING Fuel overflow hose (filler neck) hose through the “U” clamp H Band the throttle cable to the Throttle cable 1 (nut white) on the holder. frame, noting the band Throttle cable 2 (nut black) C Put the lock of the band to the direction.
  • Page 47 SPEC CABLE ROUTING Steering head pipe downtube, noting the band I Pass the brake cable through Brake cable 2 direction. (view B) the guide ring. Mainharness D Band the brake cable 2 to the J Pass the brake cable 2 through Downtube frame at the upper part of the the guide on the frame.
  • Page 48 SPEC...
  • Page 49 CHAPTER 3. PERIODIC INSPECTION AND ADJUSTMENT INTRODUCTION ..........PERIODIC MAINTENANCE/LUBRICATION INTERVALS .

  • Page 51: Periodic Inspection And Adjustment

    INTRODUCTION / INSP PERIODIC MAINTENANCE/LUBRICATION INTERVALS EB300000 PERIODIC INSPECTIONS AND ADJUSTMENTS INTRODUCTION This chapter includes all information necessary to perform recommended inspections and adjust- ments. These preventive maintenance procedures, if followed, will ensure more reliable vehicle opera- tion and a longer service life. The need for costly overhaul work will be greatly reduced. This informa- tion applies to vehicles already in service as well as to new vehicles that are being prepared for sale.
  • Page 52 — Items marked with an asterisk (*) require special tools data and technical skills for servicing. Take the scooter to a Yamaha dealer. NOTE: S The air filter needs more frequent service if you are riding in unusually wet or dusty areas.

  • Page 53: Cover And Panel

    INSP COVER AND PANEL COVER AND PANEL SIDE PANEL AND SEAT Order Job name/Part name Q’ty Remarks Side panel and seat removal Remove the parts in order. Rear panel Side panel (left) Side panel (right) Rivet Front panel NOTE: Clip Damper assembly Install the damper assembly to the body with its rod side backward and labels up-...

  • Page 54: Tail Cover And Fuel Tank

    INSP COVER AND PANEL TAIL COVER AND FUEL TANK 10 Nm (1.0 mSkg) 7 Nm (0.7 mSkg) 7 Nm (0.7 mSkg) Order Job name/Part name Q’ty Remarks Tail cover and fuel tank removal Remove the parts in order. Grab bar Seat lock bracket Tail cover Screw...
  • Page 55 INSP COVER AND PANEL 10 Nm (1.0 mSkg) 7 Nm (0.7 mSkg) 7 Nm (0.7 mSkg) Order Job name/Part name Q’ty Remarks Vacuum hose Bracket Fuel tank Fuel tank Reverse the removal procedure for installation.

  • Page 56: Footrest Board And Lower Cover

    INSP COVER AND PANEL FOOTREST BOARD AND LOWER COVER 7 Nm (0.7 mSkg) Order Job name/Part name Q’ty Remarks Footrest board and lower cover Remove the parts in order. removal Mat (footrest board) (left/right) Cover 2 Battery negative (-) lead Battery positive (+) lead Battery Flasher relay...

  • Page 57: Cowling

    INSP COVER AND PANEL COWLING 7 Nm (0.7 mSkg) 7 Nm (0.7 mSkg) Order Job name/Part name Q’ty Remarks Cowling removal Remove the parts in order. Upper cover Wind screen Inner panel Cowling body Coupler (headlight lead) NOTE: Coupler (front flasher light lead (left)) Disconnect the couplers.

  • Page 58: Handle Cover, Meter Assembly And Legshield

    INSP COVER AND PANEL HANDLE COVER, METER ASSEMBLY AND LEGSHIELD Order Job name/Part name Q’ty Remarks Handle cover, meter assembly and Remove the parts in order. legshield removal NOTE: Handle cover Coupler (meter lead) Disconnect the couplers. Meter cable Meter assembly Main switch cover Cover Legshield...

  • Page 59: Engine

    INSP VALVE CLEARANCE ADJUSTMENT YP303004 ENGINE VALVE CLEARANCE ADJUSTMENT NOTE: Valve clearance adjustment should be made with the engine cool, at room temperature. When the valve clearance is to be measured or adjusted, the piston must be at Top Dead Cen- ter (T.D.C.) on the compression stroke.

  • Page 60: Idling Speed Adjustment

    VALVE CLEARANCE ADJUSTMENT/ INSP IDLING SPEED ADJUSTMENT 6. Adjust: D Valve clearance ***************************************************** Adjustment steps: D Loosen the locknut 1 . D Turn the adjuster 3 in or out with the valve adjusting tool 2 until specified clearance is obtained. Turning in ! Valve clearance is decreased.

  • Page 61: Throttle Cable Adjustment

    IDLING SPEED ADJUSTMENT/ INSP THROTTLE CABLE ADJUSTMENT 3. Check: D Engine idling speed Out of specification ! Adjust. Engine idling speed: 1,450 X 1,550 r/min 4. Adjust: D Engine idle speed ***************************************************** Adjustment steps: D Turn the pilot screw 1 until it is lightly seated. D Turn the pilot screw out by the specified num- ber of turns.

  • Page 62: Spark Plug Inspection

    THROTTLE CABLE ADJUSTMENT/ INSP SPARK PLUG INSPECTION D Loosen the locknut 1 on the throttle cable. D Turn the adjuster 2 in or out until specified free play is obtained. Turning in ! Free play is increased. Turning out ! Free play is decreased. D Tighten the locknut.

  • Page 63: Ignition Timing Check

    SPARK PLUG INSPECTION/ INSP IGNITION TIMING CHECK Spark plug gap: 0.6 X 0.7 mm 6. Install: D Spark plug 18 Nm (1.8 mSkg) NOTE: Before installing a spark plug, clean the gasket surface and plug surface. YP303052 IGNITION TIMING CHECK NOTE: Prior to checking the ignition timing, check all electrical connections related to the ignition...

  • Page 64: Compression Pressure Measurement

    IGNITION TIMING CHECK/ INSP COMPRESSION PRESSURE MEASUREMENT NOTE: Ignition timing is not adjustable. 3. Install: D Timing check plug YP303060 COMPRESSION PRESSURE MEASUREMENT NOTE: Insufficient compression pressure will result in performance loss. 1. Remove: D Side panels Refer to “COVER AND PANEL” section. 2.

  • Page 65: Engine Oil Level Inspection

    COMPRESSION PRESSURE MEASUREMENT/ INSP ENGINE OIL REPLACEMENT Compression pressure (With oil applied into cylinder) Diagnosis Reading Higher than Worn or damaged pistons without oil Possible defective ring(s), valves, Same as without oil cylinder head gasket or piston ! Repair. Compression pressure (at sea level): Standard: 1,400 kPa (14 kg/cm , 14 bar)

  • Page 66: Recommended Engine Oil

    ENGINE OIL LEVEL INSPECTION/ INSP ENGINE OIL REPLACEMENT RECOMMENDED ENGINE OIL Refer to the chart for selection of the oils suited to the atomosperic temperature. API STANDARD: API SE or higher grade CAUTION: D Do not put in any chemical sdditives or use oils with a grade of CD a or higher.

  • Page 67: Engine Oil Pressure Inspection

    ENGINE OIL REPLACEMENT/ INSP ENGINE OIL PRESSURE INSPECTION 5. Fill: D Crankcase Oil quantity: 1.4L 6. Check: D Engine oil level Refer to “ENGINE OIL LEVEL INSPEC- TION” section. 7. Reset: D Engine oil warning circuit ***************************************************** Resetting steps: D Turn the main switch to on. D Push and hold in the reset button for 2 to 5 seconds.

  • Page 68: Transmission Oil Replacement

    ENGINE OIL PRESSURE INSPECTION/ INSP TRANSMISSION OIL REPLACEMENT D Start the engine after solving the problem(s), and recheck the oil pressure. D Tighten the oil check bolt to specification. 10 Nm (1.0 mSkg) CAUTION: D Start the engine and check the oil pres- sure with the oil check bolt loosened.

  • Page 69: Exhaust System Inspection

    TRANSMISSION OIL REPLACEMENT/ INSP EXHAUST SYSTEM INSPECTION/AIR FILTER CLEANING 7. Install: D Oil filler cap 1 D O-ring 2 8. Start the engine for several minutes to warm it up and check for the oil leakage. YP***** EXHAUST SYSTEM INSPECTION 1.

  • Page 70: Crankcase Filter Cleaning

    AIR FILTER CLEANING/ INSP CRANKCASE FILTER CLEANING 3. Inspect: D Air filter element Damaged ! Replace. 4. Clean: D Air filter element 1 Use solvent to clean the element NOTE: After cleaning, remove the remaining solvent by squeezing the element. CAUTION: Do not twist the element when squeezing the element.

  • Page 71: Coolant Level Inspection

    CRANKCASE FILTER CLEANING/ INSP COOLANT LEVEL INSPECTION CAUTION: This element is a dry type. Be careful not to stain with grease or water. 3. Clean: D Crankcase filter element 1 Blow out the dust in the element from the outer surface using compressed air. 4.

  • Page 72: Coolant Replacement

    INSP COOLANT REPLACEMENT YP303180 COOLANT REPLACEMENT 1. Remove: D Side panels D Fuel tank Refer to the “COVERS AND PANEL” section. 2. Remove: D Hose 1 (reservoir tank) Drain the reservoir tank of its coolant. 3. Remove: D Drain bolt 1 D Radiator cap Open the front trunk, remove the cover, slowly loosen to remove the radiator cap...
  • Page 73 INSP COOLANT REPLACEMENT 5. Install: D Gasket 1 D Drain bolt 2 10 Nm (1.0 mSkg) 6. Loosen: D Screw 1 (carburetor bleed) 7. Connect: D Hose (reservoir tank) 8. Fill: D Radiator (to specified level 1 ) Fill the coolant slowly, until the coolant comes out from the carburetor drain pipe.
  • Page 74 INSP COOLANT REPLACEMENT D If coolant splashes in your eyes: thoroughly wash your eyes with water and consult a doctor. D If coolant splashes on your clothes: quickly wash it away with water and then with soap and water. D If coolant is swallowed: quickly make the person who has swal- lowed it vomit and then take him to a doc- tor.

  • Page 75: Cooling System Inspection

    INSP COOLING SYSTEM INSPECTION YP303190 COOLING SYSTEM INSPECTION 1. Inspect: D Radiator 1 D Filler hose (radiator) 2 D Outlet hose (radiator) 3 D Pipe D Outlet hose (radiator) 4 Cracks/Damage ! Replace. Refer to “COOLING SYSTEM” section in chapter 5. 3-25...

  • Page 76: Chassis

    INSP FRONT BRAKE ADJUSTMENT EB304002 CHASSIS FRONT BRAKE ADJUSTMENT 1. Check: D Brake lever free play a Out of specification ! Adjust. Free play (brake lever): 2 X 5 mm (at brake lever end) 2. Adjust: D Brake lever free play ***************************************************** Adjustment steps: D Loosen the locknut 2 .

  • Page 77: Brake Fluid Level Inspection

    INSP BRAKE FLUID LEVEL INSPECTION YP304020 BRAKE FLUID LEVEL INSPECTION 1. Stand the scooter on a level surface. NOTE: Make sure the scooter is upright when inspect- ing the brake fluid level. 2. Stand the scooter on its centerstand. 3. Inspect: D Brake fluid level Brake fluid level is below the “LOWER”...

  • Page 78: Brake Pad Inspection

    BRAKE PAD INSPECTION/ INSP AIR BLEEDING (HYDRAULIC BRAKE SYSTEM) YP304030 BRAKE PAD INSPECTION 1. Operate the brake lever. 2. Inspect: D Brake pad (front) Wear indicators 1 almost touch the brake disc ! Replace the brake pads as a set. Refer to “FRONT AND REAR BRAKE”...

  • Page 79: Rear Brake Adjustment

    AIR BLEEDING (HYDRAULIC BRAKE SYSTEM)/ INSP REAR BRAKE ADJUSTMENT NOTE: When bleeding the brake system, make sure that there is always enough brake fluid in the brake fluid reservoir before applying the brake lever. Ignoring this precaution could allow air to enter the brake system, considerably lengthen- ing the bleeding procedure.

  • Page 80: Brake Shoe Inspection

    REAR BRAKE ADJUSTMENT/ INSP BRAKE SHOE INSPECTION/STEERING HEAD INSPECTION D Tighten the locknut (s). Rear wheel side: D Turn the adjuster 3 in or out until the speci- fied free play is obtained. Turning in ! Free play is decreased. Turning out ! Free play is increased.
  • Page 81 INSP STEERING HEAD INSPECTION 5. Remove: D Handlebar lower holder D Woodruff key Refer to “STEERING” section in chapter 6. Adjust: D Steering head ***************************************************** Adjustment steps: D Remove the ring nut (upper) 1 , lock washer 2 , the ring nut (center) 3 and the rubber washer.

  • Page 82: Front Fork Inspection

    STEERING HEAD INSPECTION/ INSP FRONT FORK INSPECTION D Install the lock washer 1 . NOTE: Make sure the lock washer tabs sit correctly in the ring nut slots. D Hold the ring nut (under and center), using the exhaust and ring nut wrench, and tighten the ring nut (upper) using the ring nut wrench.

  • Page 83: Swingarm Inspection

    SWINGARM INSPECTION/ REAR SHOCK ABSORBER INSPECTION/ INSP REAR SHOCK ABSORBER ADJUSTMENT YP***** SWINGARM INSPECTION Securely support the scooter so there is no danger of it falling over. 1. Place the scooter on the level place. 2. Check: D Operation Grasp the end of the swingarm and gent- ly rock the swingarm assembly back and forth.

  • Page 84: Tire Inspection

    REAR SHOCK ABSORBER ADJUSTMENT/ INSP TIRE INSPECTION ***************************************************** Adjustment steps: D Turn the adjuster ring in or out. ! Spring preload is Turning toward increased. ! Spring preload is Turning toward decreased. Hard Standard Soft Adjusting position: CAUTION: D Never turn the adjuster beyond the maximum or minimum setting.
  • Page 85 Co., Ltd. for this model. No guarantee concerning handling characteristics can be given if a tire combination other than one approved by Yamaha is used on this scooter. The front and rear tires should always be by the same manufacturer and of the same design.

  • Page 86: Wheel Inspection

    INSP TIRE INSPECTION/WHEEL INSPECTION FRONT: Manufacture Size Type 110 / 90-12 64J MB61 CHENG SHIN 110 / 90-12 64J C922 REAR: Manufacture Size Type 130 / 70-12 62L MB61 CHENG SHIN 130 / 70-12 62L C940 After mounting a tire, ride conservatively for a while to give the tire time to seat itself properly in the rim.

  • Page 87: Electrical

    INSP BATTERY INSPECTION YP305000 ELECTRICAL BATTERY INSPECTION NOTE: Since the MF battery is a sealed type battery, it is not possible to measure the specific gravity of the electrolyte in order to check the charge state of the battery. Therefore the charge of the bat- tery has to be checked by measuring the volt- age at the battery terminals.
  • Page 88 INSP BATTERY INSPECTION D Batteries generate explosive hydrogen gas. Always follow the following preven- tive measures: D Charge batteries in a well-ventilated area. D Keep batteries away from fire, sparks or open flames (e.g., welding equipment, lighted cigarettes, etc.) D DO NOT SMOKE when charging or han- dling batteries.
  • Page 89 INSP BATTERY INSPECTION D Check the condition of the battery using the Ambient charts. temperature 20_C (68_F) Example: Open-circuit voltage = 12.0 V Charging time = 6.5 hours Charge condition of the battery = 20 X 30% ***************************************************** 5. Charging method for MF batteries Condition of charge in battery (%) CAUTION: Charging...
  • Page 90 INSP BATTERY INSPECTION Charging method using a variable-current (voltage) type charger Measure the open-circuit NOTE: Charger voltage prior to charging. Voltage should be measured 30 min- AMP meter utes after the machine is stopped. Connect a charger and NOTE: AMP meter to the battery, Set the changing voltage at 16 X 17 V.
  • Page 91 INSP BATTERY INSPECTION Charging method using a constant-voltage type charger Measure the open-circuit NOTE: voltage prior to charging. Voltage should be measured 30 min- utes after the machine is stopped. Connect a charger and AMP meter to the battery, and start charging. Make sure the current is higher than the standard charging current written on...

  • Page 92: Fuse Inspection

    INSP BATTERY INSPECTION/FUSE INSPECTION 6. Inspect: D Battery terminals Dirty terminal ! Clean with wire brush. Poor connection ! Correct. NOTE: After cleaning the terminals, grease them light- 7. Install: D Battery 8. Connect: D Battery leads CAUTION: Connect the positive lead first and then connect the negative lead.

  • Page 93: Headlight Beam Adjustment

    INSP FUSE INSPECTION/HEADLIGHT BEAM ADJUSTMENT 3. Replace: D Blown fuse ***************************************************** Replacement steps: D Turn off the main switch. D Install a new fuse with the proper current rat- ing. D Turn on switches to verify operation of related electrical devices. D If the fuse blows again immediately, check the electrical circuit.
  • Page 94 INSP...
  • Page 95 CHAPTER 4. ENGINE ENGINE OVERHAUL ......... . . WIREHARNESS AND CABLE .
  • Page 96 OIL PUMP ........... . 4-42 OIL PUMP INSPECTION .

  • Page 97: Chapter 4. Engine

    ENGINE REMOVAL EB400000 ENGINE OVERHAUL ENGINE REMOVAL WIREHARNESS, CABLE 10 Nm (1.0 mSkg) 7 Nm (0.7 mSkg) Order Job name/Part name Q’ty Remarks Wireharness and cables Remove the parts in order. removal Side panel Refer to “COVER AND PANEL” Footrest board section in CHAPTER 3.
  • Page 98 ENGINE REMOVAL 10 Nm (1.0 mSkg) 7 Nm (0.7 mSkg) Order Job name/Part name Q’ty Remarks Compression spring Cable holder Cable holder Reverse the removal procedure for installation.

  • Page 99: Hoses, Air Filter Case, Engine Mounting Bolt And Engine

    ENGINE REMOVAL HOSES, AIR FILTER CASE, ENGINE MOUNTING BOLT AND ENGINE 7 Nm (0.7 mSkg) 32 Nm (3.2 mSkg) 19 Nm (1.9 mSkg) 64 Nm (6.4 mSkg) Order Job name/Part name Q’ty Remarks Hoses, air filter, engine mounting Remove the parts in order. bolt and engine removal Vacuum hose Crankcase breather hose...

  • Page 100: Engine Remounting

    ENGINE REMOVAL YP****** ENGINE REMOUNTING When remounting the engine, reverse the re- moval procedure in job instruction chart. Note the following points: 1. Install: S Engine 1 S Plane washer 2 S Rod 3 NOTE: Temporarily install the rod and engine, and then tighten the bolts and nuts to specifications.

  • Page 101: Cylinder Head

    CYLINDER HEAD CYLINDER HEAD 22 Nm (2.2 mSkg) 10 Nm (1.0 mSkg) 60 Nm (6.0 mSkg) 8 Nm (0.8 mSkg) 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Cylinder head removal Remove the parts in the order. Drain the coolant.
  • Page 102 CYLINDER HEAD 10 Nm (1.0 mSkg) 22 Nm (2.2 mSkg) 60 Nm (6.0 mSkg) 8 Nm (0.8 mSkg) 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Crankcase filter cover/seal/element 1/1/1 Plug/O-ring Cam sprocket cover/O-ring Valve cover (intake side)/O-ring Valve cover (exhaust side)/O-ring Timing chain tensioner assembly...

  • Page 103: Cylinder Head Removal

    CYLINDER HEAD YP401030 CYLINDER HEAD REMOVAL 1. Align: S “I” mark a on the rotor (with stationary pointer b on the crank case cover) NOTE: Turn the primary sheave counterclockwise with a wrench and align the “I” mark c with the cylin- der head match mark d when the piston is at TDC on the compression stroke.

  • Page 104: Cylinder Head Installation

    CYLINDER HEAD 2. Inspect: S Cylinder head Scratches/damage ! Replace. 3. Measure: S Cylinder head warpage Out of specification ! Resurface. Cylinder head warpage: Less than 0.03 mm ***************************************************** Warpage measurement and resurfacement steps: D Place a straightedge and a feeler gauge across the cylinder head.
  • Page 105 CYLINDER HEAD 3. Install: S Cam sprocket 1 S Timing chain 2 ***************************************************** Installing steps: D Turn the primary sheave counterclockwise until the TDC mark a matches the stationary pointer b . D Align the “I” mark c on the cam sprocket with the stationary pointer d on the cylinder head.
  • Page 106 CYLINDER HEAD 5. Install: S Timing chain tensioner ***************************************************** Installation steps: D Remove the tensioner cap bolt 1 and springs 2 . D Release the timing chain tensioner one-way cam 3 and push the tensioner rod 4 all the way in. D Install the tensioner with a new gasket 5 onto the cylinder.

  • Page 107: Camshaft And Rocker Arms

    CAMSHAFT AND ROCKER ARMS CAMSHAFT AND ROCKER ARMS 14 Nm (1.4 mSkg) 8 Nm (0.8 mSkg) 14 Nm (1.4 mSkg) Order Job name/Part name Q’ty Remarks Camshaft and rocker arms Remove the parts in order. removal Cylinder head Refer to “CYLINDER HEAD” section. Lock washer Plate Rocker arm shaft (intake)

  • Page 108: Camshaft Inspection

    CAMSHAFT AND ROCKER ARMS YP****** ROCKER ARM AND ROCKER ARM SHAFT REMOVAL 1. Remove: S Rocker arm shaft (intake) S Rocker arm shaft (exhaust) NOTE: Attach a rocker arm shaft puller bolt 1 and weight 2 to the rocker arm shaft and slide out the shaft.

  • Page 109: Camshaft And Rocker Arm Installation

    CAMSHAFT AND ROCKER ARMS YP402060 ROCKER ARMS ROCKER SHAFTS INSPECTION 1. Inspect: S Cam lobe contact surface 1 S Adjuster surface 2 Wear/Pitting/Scratches/Blue discolor- ation ! Replace. ***************************************************** Inspection steps: D Inspect the two contact areas on the rocker arms for signs of unusual wear. D Rocker arm shaft hole.
  • Page 110 CAMSHAFT AND ROCKER ARMS 2. Install: S Plate 1 S Look washer 2 S Bolt 3 8 Nm (0.8 mSkg) NOTE: Bend the lock washer tabs along the bolt 3 flats. 3. Apply: S Molybdenum disulfide oil (onto the rocker arm and rocker arm shaft) Molybdenum disulfide oil 4.

  • Page 111: Valves And Valve Springs

    VALVES AND VALVE SPRINGS VALVES AND VALVE SPRINGS Order Job name/Part name Q’ty Remarks Valves and valve springs removal Remove the parts in order. Cylinder head Refer to “CYLINDER HEAD” section. Rocker arm, rocker arm shaft Refer to “ROCKER ARM SHAFT AND ROCKER ARMS”...

  • Page 112: Valves And Valve Springs Removal

    VALVES AND VALVE SPRINGS YP401150 VALVES AND VALVE SPRINGS REMOVAL 1. Remove: S Valve cotters 1 NOTE: Attach a valve spring compressor and attach- ment 2 between the valve spring retainer and cylinder head to remove the valve cotters. CAUTION: Do not compress so much as to avoid dam- age to the valve spring.
  • Page 113 VALVES AND VALVE SPRINGS YP402030 4. Measure: S Spring tilt Out of specification ! Replace. Spring tilt limit: 1.7 mm (2.5_) 5. Inspect: S Spring contact face Wear/Pitting/Scratches ! Replace. 6. Measure: S Valve guide inside diameter Out of specification ! Replace. Valve guide inside diameter: Intake: 6.000 X 6.012 mm...

  • Page 114: Valve Seat Inspection

    VALVES AND VALVE SPRINGS 3. Measure: S Valve seat width a Out of specification ! Reface the valve seat. Valve seat width: Intake: 0.9 X 1.1 mm <Limit: 1.6 mm> Exhaust: 0.9 X 1.1 mm <Limit: 1.6 mm> ***************************************************** Measurement steps: D Apply Mechanic’s blueing dye (Dykem) 1 to the valve face.

  • Page 115: Valves And Valve Springs Installation

    VALVES AND VALVE SPRINGS D Turn the valve until the valve face and valve seat are evenly polished, then clean off all compound. NOTE: For best lapping results, lightly tap the valve seat while rotating the valve back and forth be- tween your hand.
  • Page 116 VALVES AND VALVE SPRINGS 4. Install: S Valve cotters 1 NOTE: Install the valve cotters while compressing the valve spring with a valve spring compressor and attachment 2 . Valve spring compressor: 90890-04019 Attachment: 90890-04108 5. Secure the valve cotters onto the valve stem by tapping lightly with a piece of wood.

  • Page 117: Cylinder And Piston

    CYLINDER AND PISTON CYLINDER AND PISTON Order Job name/Part name Q’ty Remarks Cylinder and piston removal Remove the parts in order. Cylinder head Refer to “CYLINDER HEAD” section. Joint O-ring Timing chain guide (exhaust side) Cylinder Refer to “PISTON RINGS, PISTON AND CYLINDER INSTALLATION”...

  • Page 118: Piston And Pistonrings Removal

    CYLINDER AND PISTON YP****** PISTON AND PISTON RINGS REMOVAL 1. Remove: S Piston pin circlip 1 S Piston pin 2 S Piston 3 NOTE: Before removing the piston pin circlip, cover the crankcase opening with a clean towel or rag to prevent the circlip from falling into the crank- case cavity.

  • Page 119: Piston And Piston Pin Inspection

    CYLINDER AND PISTON YP****** PISTON AND PISTON PIN INSPECTION 1. Measure: S Piston skirt diameter Out of specification ! Replace. a 5.0 mm from the piston bottom edge Piston skirt diameter: 68.965 X 68.980 mm Oversize (2) 69.5 mm Oversize (4) 70.0 mm 2.

  • Page 120: Piston Rings Inspection

    CYLINDER AND PISTON YP402111 PISTON RINGS INSPECTION 1. Measure: S Side clearance Out of specification ! Replace the piston and the piston rings as a set. NOTE: Eliminate the carbon deposits from the piston ring grooves and rings before measuring the side clearance.

  • Page 121: Piston Rings, Piston And Cylinder Installation

    CYLINDER AND PISTON EB404184 PISTON RINGS, PISTON AND CYLINDER INSTALLATION 1. Install: S Top ring 1 S 2nd ring 2 S Side rails (oil ring) 3 S Expander spacer (oil ring) 4 NOTE: D Make sure to install the piston rings so that the manufactuer’s marks or numbers are lo- cated on the upper side of the rings.
  • Page 122 CYLINDER AND PISTON 4. Position: S Piston rings NOTE: Offset the piston ring end gaps as shown. a Top ring end b Oil ring end (lower) c Oil ring end (upper) d 2nd ring end 5. Lubricate: S Piston outer surface S Piston ring S Cylinder inner surface Engine oil...

  • Page 123: Crankcase Filter Cover And Crankcase Cover (Left)

    V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE CRANKCASE FILTER COVER AND CRANKCASE COVER (LEFT) 7 Nm (0.7 mSkg) 10 Nm (1.0 mSkg) 7 Nm (0.7 mSkg) Order Job name/Part name Q’ty Remarks Crankcase filter cover and Remove the parts in order. crankcase cover (left)removal Side panel Refer to “COVER AND PANEL”...
  • Page 124 V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE *Shell BT grease No. 3 (90890-69927) 60 Nm (6.0 mSkg) 3 Nm (0.3 mSkg) 60 Nm (6.0 mSkg) Order Job name/Part name Q’ty Remarks V-belt, clutch and secondary/ Remove the parts in order. primary sheave removal Nut/Plain washer Refer to “PRIMARY SHEAVE...
  • Page 125 V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE *Shell BT grease No. 3 (90890-69927) 60 Nm (6.0 mSkg) 3 Nm (0.3 mSkg) 60 Nm (6.0 mSkg) Order Job name/Part name Q’ty Remarks Weight Refer to “PRIMARY SHEAVE Slider ASSEMBLY” section. Spacer Oil seal Reverse the removal procedure for installation.

  • Page 126: Secondary Sheave

    V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE SECONDARY SHEAVE **Apply BEL-RAY assembly lube 90 Nm (9.0 mSkg) Order Job name/Part name Q’ty Remarks Secondary sheave disassembly Disassemble the parts in order. Refer to “SECONDARY SHEAVE Clutch carrier DISASSEMBLY” section. Clutch shoe spring Refer to “SECONDARY SHEAVE Compression spring INSTALLATION”...

  • Page 127: Primary Sheave Removal

    V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE YP****** PRIMARY SHEAVE REMOVAL 1. Remove: S Nut 1 (primary sheave) S Plate washer S Primary fixed sheave 2 NOTE: Loosen the nut (primary fixed sheave) while holding the primary fixed sheave with the rotor holder 3 .

  • Page 128: Secondary Sheave Disassembly

    V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE 3. Remove: S Clutch assembly 1 S V-belt 2 NOTE: Remove the V-belt from the primary sheave side with clutch assembly. YP****** SECONDARY SHEAVE DISASSEMBLY 1. Remove: S Nut 1 (secondary sheave) NOTE: Loosen the nut 1 while attaching the clutch spring compressor 2 and clutch spring holder arm 3 and release the compressed spring after removing the nut.

  • Page 129: Belt Inspection

    V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE YP****** V-BELT INSPECTION 1. Inspect: S V-belt 1 Cracks/Wear/Scaling/Chipping ! Re- place. Oil/Grease ! Check primary sheave and secondary sheave. 2. Measure: S V-belt width 2 Out of specification ! Replace V-belt width: 22.6 mm <Limit: 21.0 mm>...

  • Page 130: Primary Sheave Assembly

    V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE YP****** PRIMARY SHEAVE ASSEMBLY 1. Clean: S Primary sliding sheave face 1 S Primary fixed sheave face 2 S Collar 3 S Weight 4 S Primary sliding sheave cam face 5 NOTE: Remove any excess grease. 2.
  • Page 131 V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE 3. Install: S Guide pin 1 4. Apply: S BEL-RAY assembly lube (to the guide pin sliding groove 1 , and and oil seal 2 5. Install: S Secondary sheave complete 1 S Compression spring S Clutch carrier 2 NOTE: Temporarily tighten the nut 5 while attaching...
  • Page 132 V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE 7. Install: S Nut 1 (clutch carrier) 90 Nm (9.0 mSkg) NOTE: Tighten the nut (clutch carrier), using the lock- nut wrench 3 while holding the clutch carrier with the rotor holder 2 . Rotor holder: 90890-01235 Locknut wrench: 90890-01348...

  • Page 133: A.c. Magneto And Starter Clutch

    A.C. MAGNETO AND STARTER CLUTCH A.C. MAGNETO AND STARTER CLUTCH MAGNETO COVER AND STARTOR COIL 7 Nm (0.7 mSkg) 20 Nm (2.0 mSkg) 7 Nm (0.7 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Magneto cover and startor coil Remove the parts in order.
  • Page 134 A.C. MAGNETO AND STARTER CLUTCH A.C. MAGNETO AND STARTER CLUTCH 10 Nm (1.0 mSkg) 80 Nm (8.0 mSkg) Order Job name/Part name Q’ty Remarks A.C. magneto and starter clutch Remove the parts in order. removal Rotor Refer to “A.C. MAGNETO ROTOR REMOVAL/INSTALLATION”...

  • Page 135: Magneto And Starter Clutch

    A.C. MAGNETO AND STARTER CLUTCH YP401081 A.C. MAGNETO ROTOR REMOVAL 1. Remove: S Nut 1 (rotor) S Plain washer 2 NOTE: D Loosen the nut (rotor) 1 while holding the ro- tor with a sheave holder 3 . D Do not allow the sheave holder to touch the projection on the rotor.

  • Page 136: Starter Drive Gear Inspection

    A.C. MAGNETO AND STARTER CLUTCH YP402163 STARTER DRIVE GEAR INSPECTION 1. Inspect: S Starter idle gear teeth S Starter drive gear teeth S Starter wheel gear teeth Burrs/chips/roughness/wear place. 2. Check: S Starter clutch operation Push the dowel pins to the arrow direction. Unsmooth operation ! Replace.
  • Page 137 A.C. MAGNETO AND STARTER CLUTCH 3. Tighten: S Nut (rotor) 1 80 Nm (8.0 mSkg) NOTE: Tighten the nut (rotor) 1 while holding the mag- neto rotor 2 with a sheave holder 3 . Sheave holder: 90890-01701 4-41...

  • Page 138: Oil Pump

    OIL PUMP OIL PUMP 7 Nm (0.7 mSkg) 12 Nm (1.2 mSkg) Order Job name/Part name Q’ty Remarks Oil pump removal Remove the parts in order. Refer to the “A.C. MAGNETO AND A.C. magneto STARTER CLUTCH” section. Cover Pump driven gear Dowel pin Oil pump assembly Gasket...

  • Page 139: Oil Pump Inspection

    OIL PUMP EB402140 OIL PUMP INSPECTION 1. Inspect: S Drive gear (oil pump) S Driven gear (oil pump) 1 S Pump housing S Pump housing cover Wear/cracks/damage! Replace 2. Measure: S Tip clearance A (between the inner rotor 1 and the outer rotor 2 ) S Side clearance B (between the outer rotor 2 and the pump...

  • Page 140: Transmission

    TRANSMISSION TRANSMISSION 16 Nm (1.6 mSkg) Order Job name/Part name Q’ty Remarks Transmission removal Remove the parts in order. Rear wheel Refer to “REAR WHEEL/REAR BRAKE” section in CHAPTER 7. Refer to “V-BELT, CLUTCH, Crankcase cover (left) SECONDARY/PRIMARY SHEAVE” section. Drain the transmission oil.
  • Page 141 TRANSMISSION 16 Nm (1.6 mSkg) Order Job name/Part name Q’ty Remarks Drive axle Main axle Primary driven gear Plain washer Reverse the removal procedure for installation. 4-45...

  • Page 142: Crankcase And Crankshaft

    CRANKCASE AND CRANKSHAFT CRANKCASE AND CRANKSHAFT 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Crankcase and crankshaft Remove the parts in the order. removal Engine removal Refer to “ENGINE REMOVAL” section. Cylinder head Refer to “CYLINDER HEAD” section. Cylinder, piston Refer to “CYLINDER AND PISTON”...
  • Page 143 CRANKCASE AND CRANKSHAFT 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Timing chain guide (intake) Crankcase (right) Refer to “CRANKSHAFT INSTALLATION” section. Dowel pin Crankshaft assembly Refer to “CRANKSHAFT REMOVAL/ INSTALLATION” section. Timing chain Crankcase (left) Oil seal Reverse the removal procedure for...

  • Page 144: Crankshaft Removal

    CRANKCASE AND CRANKSHAFT YP****** CRANKSHAFT REMOVAL 1. Remove: S Crankshaft assembly S Timing chain 1 NOTE: D Before removing the crankshaft assembly, remove the timing chain from the crank shaft sprocket. D If the timing chain hooks to the crankshaft sprocket, the crankshaft cannot be removed.
  • Page 145 1. Clean all the gasket mating surface and crankcase mating surface thoroughly. 2. Apply: S Sealant (onto the crankcase mating surfaces) Yamaha bond No. 1215 NOTE: DO NOT ALLOW any sealant to come in con- tact with the oil gallery. 3. Install:...
  • Page 147 CHAPTER 5. COOLING SYSTEM RADIATOR ........... . INSPECTION .

  • Page 149: Cooling System Radiator

    COOL RADIATOR YP500000 COOLING SYSTEM RADIATOR 23 Nm (2.3 mSkg) Order Job name/Part name Q’ty Remarks Radiator removal Remove the parts in order. Drain the coolant. Refer to “COOLANT REPLACEMENT” section in CHAPTER 3. Fuel tank Refer to “COVER AND PANEL” Footrest board, under cover section in CHAPTER 3.

  • Page 150: Inspection

    COOL RADIATOR YP500030 INSPECTION 1. Inspect: D Radiator 1 Obstruction ! Blow out with com- pressed air through the rear of the radia- tor. Flattened fins ! Repair or replace. If flattened over the 20 % of radiator fin, repair or replace the radiator. CAUTION: Use only specified adhesive to repair the ra- diator.

  • Page 151: Water Pump

    COOL WATER PUMP WATER PUMP Oil pump side 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Water pump removal Remove the parts in order. Drain the coolant. Refer to “COOLANT REPLACEMENT” section in CHAPTER 3.
  • Page 152 COOL WATER PUMP Oil pump side 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Impeller shaft Refer to “WATER PUMP O-ring INSTALLATION” section. O-ring Reverse the removal procedure for installation.

  • Page 153: Inspection

    1. Install: D Mechanical seal 1 ***************************************************** Installation steps: D Apply the Yamaha bond 1215 to the outside of the mechanical seal. D Install the mechanical seal by using the me- chanical seal installer 2 and middle shaft bearing driver 3 .
  • Page 154 COOL WATER PUMP 2. Install: D Mechanical seal 1 Apply coolant to the outside of the me- chanical seal before installing. NOTE: Do not smear any oils grease on to the ring side of the mechanical seal. 3. Inspect: D Mechanical seal, slip ring side 1 Inspect the slip ring side of the mechani- cal seal and the impeller 2 for level installation.

  • Page 155: Thermostat

    COOL THERMOSTAT THERMOSTAT 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Thermostat removal Remove the parts in order. Drain the coolant Refer to “COOLANT REPLACEMENT” section in CHAPTER 3. Side panel Refer to “COVER AND PANEL” Fuel tank section in CHAPTER 3.

  • Page 156: Inspection

    COOL THERMOSTAT EB502010 INSPECTION 1. Inspect: D Thermostatic valve Valve does not open at 80.5 X 83.5_C ! Replace. ***************************************************** Inspection steps: D Suspend the thermostatic valve in a vessel. D Place a reliable thermometer in water. D Observe the thermometer, while continually stirring the water.
  • Page 157 CHAPTER 6. CARBURETION CARBURETION ..........CARBURETOR DISASSEMBLY .

  • Page 159: Carburetion

    CARB CARBURETOR EB600000 CARBURETION CARBURETOR 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Carburetor removal Remove the parts in order. Side panel Refer to “COVER AND PANEL” Fuel tank section in CHAPTER 3. Drain the coolant Refer to “COOLANT REPLACEMENT” section in CHAPTER 3.

  • Page 160: Carburetor Disassembly

    CARB CARBURETOR CARBURETOR DISASSEMBLY Order Job name/Part name Q’ty Remarks Carburetor disassembly Disassemble the parts in order. Auto choke unit Throttle stop screw set Pilot screw set Cover/Diaphragm spring Piston valve Jet needle ass’y Coasting enricher Refer to “CARBURETOR ASSEMBLY” Accererating pump Float chamber section.
  • Page 161 CARB CARBURETOR Order Job name/Part name Q’ty Remarks Float Needle valve Refer to “CARBURETOR ASSEMBLY” Main jet section. Pilot jet Main nozzle Reverse the disassembly procedure for assembly.

  • Page 162: Assembly

    CARB CARBURETOR YP600041 ASSEMBLY Reverse the “DISASSEMBLY” procedure. Note the following points. CAUTION: D Before assembling, wash all parts in clean petroleum based solvent. D Always use a new gasket. 1. Install: D Main nozzle 1 D Main jet 2 D Pilot jet 3 2.

  • Page 163: Fuel Level Adjustment

    CARB CARBURETOR Float height (F.H.): 27 mm Out of specification ! Replace. ***************************************************** 5. Install: D Diaphragm 1 NOTE: Align the tab a on the diaphragm with the slot b on the carburetor body. 6. Install: D Compression spring 1 D Cover 2 YP600060 FUEL LEVEL ADJUSTMENT...

  • Page 164: Auto Choke Inspection

    CARB CARBURETOR D Put a garage jack under the engine to ensure that the carburetors are positioned vertically. D Connect the fuel level gauge 1 to the drain pipe 2 . Fuel level gauge: 90890-01312 D Loosen the drain screw 3 . D Hold the gauge vertically next to the float chamber line.

  • Page 165: Fuel Pump Inspection

    CARB CARBURETOR YP****** FUEL PUMP INSPECTION 1. Remove: D Side panels Refer to “COVER AND PANEL” section in CHAPTER 3. 2. Inspect: D Fuel pump ***************************************************** Inspection steps: D Place the receptacle under the fuel pipe end. D Start engine, and inspect gasoline to flow out from fuel pipe 1 .
  • Page 166 CARB...
  • Page 167 CHAPTER 7. CHASSIS FRONT WHEEL AND BRAKE DISC ......FRONT WHEEL AND BRAKE DISC .

  • Page 169: Chapter 7. Chassis

    CHAS FRONT WHEEL AND BRAKE DISC CHASSIS FRONT WHEEL AND BRAKE DISC FRONT WHEEL AND BRAKE DISC 70 Nm (7.0 mSkg) 23 Nm (2.3 mSkg) Order Job name/Part name Q’ty Remarks Front wheel and brake disc Remove the parts in order. removal Securely support the scooter so there is no danger of it falling over.

  • Page 170: Front Wheel Disassembly

    CHAS FRONT WHEEL AND BRAKE DISC FRONT WHEEL DISASSEMBLY Order Job name/Part name Q’ty Remarks Front wheel disassembly Remove the parts in order. Oil seal Refer to “FRONT WHEEL Bearing DISASSEMBLY /ASSEMBLY” section. Spacer Bearing Reverse the removal procedure for installation.

  • Page 171: Front Wheel Disassembly

    CHAS FRONT WHEEL AND BRAKE DISC YP****** FRONT WHEEL DISASSEMBLY 1. Remove: S Bearing 1 S Spacer Remove the bearing using a general bear- ing puller 2 . CAUTION: Handle the wheel with care not to damage the brake disc. If the brake disc is damaged, replace.

  • Page 172: Brake Disc Inspection

    CHAS FRONT WHEEL AND BRAKE DISC 5. Inspect: S Collar Grooved wear ! Replace the collar and the oil seal as a set. YP****** BRAKE DISC INSPECTION 1. Measure: S Brake disc deflection Maximum deflection: 0.15 mm Out of specification ! Replace. 2.

  • Page 173: Front Wheel Installation

    CHAS FRONT WHEEL AND BRAKE DISC 2. Install: S Brake disc 1 23 Nm (2.3 mSkg) NOTE: Tighten the bolts (brake disc) in stage using a crisscross pattern. EB700030 FRONT WHEEL INSTALLATION Reverse the “REMOVAL” procedure. Note the following points. 1.

  • Page 174: Wheel Static Balance Adjustment

    CHAS FRONT WHEEL AND BRAKE DISC YP700040 WHEEL STATIC BALANCE ADJUSTMENT NOTE: D After replacing the tire and/or rim, the wheel static balance should be adjusted. D Adjust the front wheel static balance with the brake disc installed. 1. Remove: S Balancing weight 2.
  • Page 175 CHAS FRONT WHEEL AND BRAKE DISC 5. Check: S Wheel static balance ***************************************************** Checking steps: D Turn the wheel so that it comes to each point as shown. D Check that the wheel is at rest at each point. If not, readjust the front wheel static balance. *****************************************************...

  • Page 176: Rear Wheel And Rear Brake

    CHAS REAR WHEEL AND REAR BRAKE REAR WHEEL AND REAR BRAKE 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Rear wheel and rear brake removal Remove the part in order. Swingarm Refer to “REAR SHOCK ABSORBER AND SWINGARM” section. Adjuster Brake cable Compression spring...
  • Page 177 CHAS REAR WHEEL AND REAR BRAKE 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Camshaft shim Camshaft seal Reverse the removal procedure for installation.

  • Page 178: Rear Wheel Inspection

    CHAS REAR WHEEL AND REAR BRAKE EB701020 REAR WHEEL INSPECTION 1. Inspect: S Rear wheel axle S Rear wheel S Rear wheel bearings S Oil seals Refer to “FRONT WHEEL”. 2. Measure: S Rear wheel runout Refer to “FRONT WHEEL”. EB701021 REAR BRAKE INSPECTION 1.

  • Page 179: Rear Brake Installation

    CHAS REAR WHEEL AND REAR BRAKE 4. Inspect: S Brake drum inner surface S Oil/scratches ! Repair. S Oil Use a rag soaked in lacquer thinner or sol- vent. S Scratches Use an emery cloth (lightly and evenly polishing) 5. Inspect: S Camshaft face.

  • Page 180: Front Brake

    CHAS FRONT BRAKE FRONT BRAKE BRAKE PAD 23 Nm (2.3 mSkg) Order Job name/Part name Q’ty Remarks Brake pad removal Remove the parts in order. Caliper support bolt Refer to “BRAKE PAD Brake pad REPLACEMENT” section. Pad support Reverse the removal procedure for installation.

  • Page 181: Brake Pad Replacement

    CHAS FRONT BRAKE YP702010 BRAKE PAD REPLACEMENT NOTE: It is not necessary to disassemble the brake cal- iper and brake hose to replace the brake pads. 1. Remove: S Bolt (caliper support bolt) 1 Move the direction brake caliper to the ar- row mark.

  • Page 182: Master Cylinder

    CHAS FRONT BRAKE MASTER CYLINDER 10 Nm (1.0 mSkg) 10 Nm (1.0 mSkg) 26 Nm (2.6 mSkg) Order Job name/Part name Q’ty Remarks Master cylinder removal Remove the parts in order. Drain the brake fluid Refer to “BRAKE FLUID REPLACE- MENT”...

  • Page 183: Master Cylinder Disassembly

    CHAS FRONT BRAKE MASTER CYLINDER DISASSEMBLY Order Job name/Part name Q’ty Remarks Master cylinder disassembly Remove the parts in order. Master cylinder boot Circlip Refer to “MASTER CYLINDER Master cylinder assembly ASSEMBLY” section. Spring Reverse the disassembly procedure for assembly. 7-15...

  • Page 184: Master Cylinder Inspection

    CHAS FRONT BRAKE YP702040 MASTER CYLINDER INSPECTION 1. Inspect: S Master cylinder 1 Wear/scratches ! Replace the master cylinder assembly. S Master cylinder cup 2 S Cracks/damage ! Replace. 2. Inspect: S Master cylinder S Scratches/wear/damage ! Replace the master cylinder assembly. 3.
  • Page 185 CHAS FRONT BRAKE 2. Install: S Spring 1 Install the spring with its smaller diameter to the master cylinder piston. S Master cylinder kit 2 3. Install: S Circlip 1 Install the circlip securely into the master cylinder groove. S Master cylinder boot 2 YP****** MASTER CYLINDER INSTALLATION 1.
  • Page 186 CHAS FRONT BRAKE 3. Air bleed: S Brake system Refer to “AIR BLEEDING” section in CHAPTER 3. D Use only designated quality brake fluid: Otherwise, the rubber seals may deterio- rate, causing leakage and poor brake per- formance. D Refill with the same type of brake fluid: mixing fluids may result in a harmful chemical reaction and lead to poor perfor- mance.

  • Page 187: Caliper

    CHAS FRONT BRAKE CALIPER 26 Nm (2.6 mSkg) 23 Nm (2.3 mSkg) Order Job name/Part name Q’ty Remarks Caliper removal Remove the parts in order. Drain the brake fluid Refer to “BRAKE FLUID REPLACE- Brake hose holder MENT” section in CHAPTER 3. Union bolt Plain washer Refer to “CALIPER INSTALLATION”...

  • Page 188: Caliper Disassembly

    CHAS FRONT BRAKE CALIPER DISASSEMBLY 6 Nm (0.6 mSkg) Order Job name/Part name Q’ty Remarks Caliper disassembly Remove the parts in order. Brake pad Pad support Caliper piston Refer to “BRAKE CALIPER DIS- Dust seal ASSEMBLY /ASSEMBLY” section. Piston seal Bleed screw/Cap Reverse the disassembly procedure for assembly.

  • Page 189: Brake Caliper Disassembly

    CHAS FRONT BRAKE YP702020 BRAKE CALIPER DISASSEMBLY NOTE: Before disassembling either brake caliper, drain the brake fluid from the brake hose, mas- ter cylinder, brake caliper and reservoir tank. 1. Remove: S Brake caliper piston ***************************************************** Removal steps: S Blow compressed air into the hose joint opening to force out the caliper piston from the brake caliper body.

  • Page 190: Brake Caliper Assembly

    CHAS FRONT BRAKE EB702050 BRAKE CALIPER ASSEMBLY D All internal brake components should be cleaned and lubricated with new brake fluid only before installation. Recommended brake fluid: DOT #4 D Replace the caliper piston seals whenev- er a brake caliper is disassembled. 1.

  • Page 191: Front Fork

    CHAS FRONT FORK FRONT FORK FRONT FORK 45 Nm (4.5 mSkg) 23 Nm (2.3 mSkg) 23 Nm (2.3 mS kg) 49 Nm (4.9 mSkg) Order Job name/Part name Q’ty Remarks Front fork removal Remove the parts in order. Front wheel Refer to “FRONT WHEEL”...

  • Page 192: Front Fork Disassembly

    CHAS FRONT FORK FRONT FORK DISASSEMBLY 45 Nm (4.5 mSkg) 23 Nm (2.3 mSkg) Order Job name/Part name Q’ty Remarks Front fork disassembly Remove the parts in order. Cap bolt Refer to “FRONT FORK REMOVAL/ INSTALLATION” section. O-ring Fork spring Refer to “FRONT FORK ASSEMBLY”...

  • Page 193: Front Fork Removal

    CHAS FRONT FORK YP****** FRONT FORK REMOVAL D Securely support the scooter so there is no danger of it falling over. D Stand the scooter on a level surface. D Stand the scooter on its centerstand. 1. Loosen: S Bolt (lower bracket upper) 1 NOTE: Loosen only the upper bolt.

  • Page 194: Front Fork Inspection

    CHAS FRONT FORK 2. Remove: S Inner tube S Oil lock pice 3. Remove: S Oil seal 1 CAUTION: Never reuse the oil seal. 2 Rag YP703030 FRONT FORK INSPECTION 1. Inspect: S Inner tube bending Inner tube bending limit: 0.2 mm Scratches/bends/damage ! Replace.
  • Page 195 CHAS FRONT FORK 2. Install: S Inner tube 1 Into outer tube 2 . 3. Install: S Plain washer 1 S Bolt (damper rod) 2 4. Tighten: S Bolt (damper rod) 1 23 Nm (2.3 mSkg) NOTE: Tighten damper rod bolt 1 while holding the damper rod with a T-handle 2 and a damper rod holder 3 .
  • Page 196 CHAS FRONT FORK 7. Inspect: S Inner tube operation Unsmooth operation ! Disassembly and recheck. 8. Fill: S Fork oil Oil quantity: 0.142 L Recommended oil: Fork oil 15 WT or equivalent 9. After filling up, slowly pump the fork up and down to distribute the fork oil.

  • Page 197: Front Fork Installation

    CHAS FRONT FORK EB703050 FRONT FORK INSTALLATION Reverse the “REMOVAL“ procedure. Note the following points. 1. Install: S Front fork 1 Temporary tighten the pinch bolts. NOTE: Pull up the inner tube until its end flushes the top of the under bracket 2 , then temporarily tighten the bolt (under bracket lower) 3 .

  • Page 198: Handlebar

    CHAS HANDLEBAR HANDLEBAR 23 Nm (2.3 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Handlebar removal Remove the parts in order. Handlebar upper cover Refer to ”COVER AND PANEL” section in CHAPTER 3. Rear view mirror (right) Left-thread screw.
  • Page 199 CHAS HANDLEBAR 23 Nm (2.3 mSkg) 10 Nm (1.0 mSkg) Order Job name/Part name Q’ty Remarks Handlebar switch (left) Refer to “HANDLEBAR Grip end (left) INSTALLATION” section. Grip Refer to “HANDLEBAR REMOVAL” section. Upper handlebar holder Refer to “HANDLEBAR Handlebar INSTALLATION”...

  • Page 200: Handlebar Removal

    CHAS HANDLEBAR YP****** HANDLEBAR REMOVAL 1. Remove: S Grip (Left) ***************************************************** Removal steps: D Remove the grip end (left). D Blow with compressed air between the han- dlebar and adhesive side of the grip to re- move. ***************************************************** YP704020 HANDLEBAR INSPECTION 1.
  • Page 201 CHAS HANDLEBAR 4. Install: S Handlebar switch (left) 1 NOTE: Align the handlebar switch mating surface with the punched mark a on the handlebar. 5. Install: S Lever holder (left) 1 NOTE: Align the lever holder mating surface with the punched mark a on the handlebar.

  • Page 202: Steering

    CHAS STEERING STEERING 139 Nm (13.9 mSkg) 1st step: 38 Nm (3.8 mSkg) 2nd step: Loosen the ring nut 1 / 4 turn. 3rd step: 22 Nm (2.2 mSkg) 75 Nm (7.5 mSkg) Order Job name/Part name Q’ty Remarks Steering removal Remove the parts in order.
  • Page 203 CHAS STEERING 139 Nm (13.9 mSkg) 1st step: 38 Nm (3.8 mSkg) 2nd step: Loosen the ring nut 1 / 4 turn. 3rd step: 22 Nm (2.2 mSkg) 75 Nm (7.5 mSkg) Order Job name/Part name Q’ty Remarks Ball bearing Ball bearing Refer to “STEERING Ball race 1...

  • Page 204: Steering Removal

    CHAS STEERING YP704010 STEERING REMOVAL D Securely support the scooter so that there is no danger of it falling over. D Stand the scooter on a level surface. 1. Remove: S Handlebar lower holder 1 S Woodruff key 2 NOTE: Remove the handlebar lower holder by loosen- ing the ring nut (upper) 3 gradually.

  • Page 205: Steering Installation

    CHAS STEERING ***************************************************** Bearing race replacement steps: D Remove the bearing races on the head pipe using long rod 1 and the hammer as shown. D Remove the bearing race on the under brack- et using the floor chisel 2 and the hammer as shown.

  • Page 206: Rear Shock Absorber And Swingarm

    CHAS REAR SHOCK ABSORBER AND SWINGARM REAR SHOCK ABSORBER AND SWINGARM 40 Nm (4.0 mSkg) 19 Nm (1.9 mSkg) 7 Nm (0.7 mSkg) 135 Nm (13.5 mSkg) 20 Nm (2.0 mSkg) 23 Nm (2.3 mSkg) 20 Nm (2.0 mSkg) 53 Nm (5.3 mSkg) Order Job name/Part name Q’ty...
  • Page 207 CHAPTER 8. ELECTRICAL ELECTRICAL COMPONENTS ........CIRCUIT DIAGRAM .

  • Page 209: Chapter 8. Electrical Electrical Components

    ELEC ELECTRICAL COMPONENTS EB800000 ELECTRICAL ELECTRICAL COMPONENTS 1 Main switch 8 Thermo unit 2 Ignition coil 9 Ignitor unit 3 Spark plug cap Sidestand switch 4 Fuel sender Battery 5 Rectifier/ Regulator Starter relay 6 Starting circuit cut-off relay Flasher relay 7 Wireharness Horn...

  • Page 210: Circuit Diagram

    ELEC CIRCUIT DIAGRAM CIRCUIT DIAGRAM...
  • Page 211 ELEC CIRCUIT DIAGRAM 1 A.C. magneto Turn switch 2 Rectifier regulator Horn switch 3 Main switch Dimmer switch 4 Battery Pass switch 5 Main fuse Handlebar switches (left) 6 Starter relay Tail / Brake light 7 Starter motor Licence light 8 Thermo switch (auto choke) Rear flasher lights 9 Auto choke...

  • Page 212: Checking Switches

    ELEC CHECKING SWITCHES YP-N CHECKING SWITCHES CHECKING STEPS Using pocket tester, check switches for continu- ity between their terminals to determine wheth- er they are correctly connected. Repalce the switch component if any of the combinations does not produce the correct reading.

  • Page 213: Switch Position And Terminal Connection

    ELEC CHECKING SWITCHES YP****** SWITCH POSITION AND TERMINAL CONNECTION Before checking a switch refer to the checking switches as shown in the left page and check for the correct terminal connections (closed circuit) according to the color combinations shown in the chart.

  • Page 214: Ignition System

    ELEC IGNITION SYSTEM EB802000 IGNITION SYSTEM CIRCUIT DIAGRAM 3 Main switch 4 Battery 5 Main fuse Ignitor unit Ignition coil Spark plug Pickup coil Sidestand switch Engine stop switch...

  • Page 215: Troubleshooting

    ELEC IGNITION SYSTEM YP802010 TROUBLESHOOTING IF THE IGNITION SYSTEM FAILS TO OPERATE. (NO SPARK OR INTERMITTENT SPARK) Procedure Check: 1. Fuse (Main) 7. Pickup coil resistance 2. Battery 8. Main switch 3. Spark plug 9. Engine stop switch 4. Ignition spark gap 10.
  • Page 216 ELEC IGNITION SYSTEM YP****** 4. Ignition spark gap S Disconnect the spark plug cap from the spark plug. S Connect the ignition checker as shown. Spark plug S Turn the main switch to “ON”. S Check the ignition spark gap S Check the spark by pushing the starter MEETS SPECIFICATION switch, and increase the spark gap until a...
  • Page 217 ELEC IGNITION SYSTEM YP****** Tester (+) lead ! 6. Ignition coil resistance Red/White Terminal S Disconnect the ignition coil connector from Tester (–) lead ! the wireharness. Orange Terminal S Connect the pocket tester ( 1) to the ignition coil. S Check if the primary coil has the specified re- sistance.
  • Page 218 ELEC IGNITION SYSTEM YP****** 7. Pickup coil resistance S Disconnect the pickup coil coupler from the wireharness. S Connect the pocket tester ( 100) to the pickup coil coupler. Tester (+) lead ! Yellow Terminal Tester (–) lead ! Blue Terminal OUT OF SPECIFICATION S Check the pickup coil has the specified re- sistance.

  • Page 219: Charging System

    ELEC CHARGING SYSTEM YP804000 CHARGING SYSTEM CIRCUIT DIAGRAM 1 A.C. magneto 2 Rectifier regulator 4 Battery 5 Main fuse 8-11...

  • Page 220: Troubleshooting

    ELEC CHARGING SYSTEM YP804010 TROUBLESHOOTING IF THE BATTERY IS NOT CHARGED Procedure Check: 1. Fuse (Main) 4. Stator coil resistance 2. Battery 5. Wiring system (entire charging system) 3. Charging voltage NOTE: D Remove the following parts before trouble- shooting. 1) Side panels 2) Tail cover D Use the special tools specified in the trouble-...
  • Page 221 ELEC CHARGING SYSTEM YP****** 3. Charging voltage S Connect the engine tachometer to the spark plug lead S Connect the pocket tester (DC20 V) to the battery. Tester (+) lead ! Battery (+) terminal Tester (–) lead ! Battery (–) terminal S Measure the battery terminal voltage.
  • Page 222 ELEC CHARGING SYSTEM YP****** 4. Starter coil resistance S Remove the A.C. magneto coupler from wireharness. S Connect the pocket tester ( 1) to the sta- tor coil. Tester (+) lead ! white terminal Tester (–) lead ! White terminal OUT OF SPECIFICATION S Measure the stator coil resistance.

  • Page 223: Electric Starting System

    ELEC ELECTRIC STARTING SYSTEM EB80300 ELECTRIC STARTING SYSTEM CIRCUIT DIAGRAM 3 Main switch 4 Battery 5 Main fuse 6 Starter relay 7 Starter motor Sidestand switch Starting circuit cut-off relay Starter switch Engine stop switch Rear brake switch Front brake switch 8-15...

  • Page 224: Troubleshooting

    ELEC ELECTRICAL STARTING SYSTEM YP803020 TROUBLESHOOTING IF THE STARTER MOTOR FAILS TO OPERATE. Procedure Check: 1. Fuse (Main) 7. Engine stop switch 2. Battery 8. Sidestand switch 3. Starter motor 9. Front/Rear brake switch 4. Starter relay 10. Starter switch 5.
  • Page 225 ELEC ELECTRICAL STARTING SYSTEM YP****** 3. Starter motor DOES NOT MOVE S Connect the battery positive terminal and starter motor cable using a jumper lead. S Check the starter motor operation. Repair or replace the starter motor. A wire used as a jumper lead must have the equivalent capacity as that of the battery MOVES lead or more, otherwise it may burn.
  • Page 226 ELEC ELECTRICAL STARTING SYSTEM NO CONTINUITY YP****** 6. Main switch Refer to “CHECKING SWITCHES” section. Replace the main switch. CONTINUITY NO CONTINUITY YP****** 7. Engine stop switch Refer to “CHECKING SWITCHES” section. Replace the right handlebar switch. CONTINUITY NO CONTINUITY YP****** 8.

  • Page 227: Starter Motor

    ELEC ELECTRICAL STARTING SYSTEM STARTER MOTOR 7 Nm (0.7 mSkg) 7 Nm (0.7 mSkg) 10 Nm (1.0 mSkg) 5 Nm (0.5 mSkg) Order Job name/Part name Q’ty Remarks Starter motor removal Remove the parts in order. Air cleaner case Refer to “ENGINE REMOVAL AND INSTALLATION”...
  • Page 228 ELEC ELECTRICAL STARTING SYSTEM YP803034 Inspection and repair 1. Inspect: S Commutator Dirt ! Clean it with #600 grit sandpaper. 2. Measure: S Commutator diameter a Commutator wear limit: 27 mm Out of specification ! Replace the starter motor 3. Measure: S Mica undercut a Mica undercut: 0.7 mm...
  • Page 229 ELEC ELECTRICAL STARTING SYSTEM Brush spring force: 570 X 920 g 7. Inspect: S Bearing S Oil seal Wear/damage ! Repalce. YP****** Assembly Reverse the “Removal” procedure. Note the following points. 1. Install: S Brush holder 1 NOTE: Align the projection a on the brush seat with the slot b on the housing.

  • Page 230: Lighting System

    ELEC LIGHTING SYSTEM EB804000 LIGHTING SYSTEM CIRCUIT DIAGRAM 3 Main switch 4 Battery 5 Main fuse Lights switch Dimmer switch Pass switch Tail / Brake light Licence light Head light Auxiliary light Meter lights 8-22...

  • Page 231: Troubleshooting

    ELEC LIGHTING SYSTEM YP805010 TROUBLESHOOTING IF THE HEADLIGHT, HIGH BEAM INDICATOR LIGHT, TAILLIGHT, MARKER LIGHT AND/OR METER LIGHT FAIL TO COME ON. Procedure Check: 1. Fuse (Main) 4. Lights switch 2. Battery 5. Dimmer switch and pass switch 3. Main switch 6.
  • Page 232 ELEC LIGHTING SYSTEM NO CONTINUITY YP****** 5. Dimmer switch/Pass switch Refer to “CHECKING SWITCHES” section. Replace the left handlebar switch. YP****** 6. Wiring connection POOR CONNECTIONS S Check the connections of the entire lighting system. Refer to “WIRING DIAGRAM”. Correct. Check the condition of each of the lighting system’s circuits.
  • Page 233 ELEC LIGHTING SYSTEM S Turn the main switch to on. OUT OF SPECIFICATION S Turn the light switch to on position. S Turn the dimmer switch to low beam or high beam. S Pass switch to push in. The wiring circuit from the main switch to S Check for voltage (12 V) on the lead at bulb bulb socket connector is faulty.
  • Page 234 ELEC LIGHTING SYSTEM YP805022 3. The taillight fails to come on. NO CONTINUITY 1. Bulb and bulb socket Refer to “CHECKING SWITCHES” section. Replace the bulb and/or bulb socket. CONTINUITY 2. Voltage S Connect the pocket tester (DC20 V) to the bulb socket connector.
  • Page 235 ELEC LIGHTING SYSTEM YP805023 4. If the auxiliary light fails to come on. NO CONTINUITY 1. Bulb and bulb socket Refer to “CHECKING SWITCHES” section. Replace the bulb and/or bulb socket. CONTINUITY 2. Voltage S Connect the pocket tester (DC20 V) to the bulb socket connector.

  • Page 236: Signal System

    ELEC SIGNAL SYSTEM EB806000 SIGNAL SYSTEM CIRCUIT DIAGRAM 3 Main switch Turn indicator lights 4 Battery Fuel gauge 5 Main fuse Fuel sender Rear brake switch Front brake switch Flasher relay Horn Turn switch Horn switch Tail / Brake light Rear flasher lights Front flasher lights 8-28...

  • Page 237: Troubleshooting

    ELEC SIGNAL SYSTEM YP806010 TROUBLESHOOTING IF THE FLASHER LIGHT, BRAKE LIGHT AND/OR INDICATOR LIGHT FAIL TO COME ON. IF THE HORN FAILS TO SOUND. Procedure Check: 1. Fuse (Main) 3. Main switch 2. Battery 4. Wiring connection (entire signal system) NOTE: D Remove the following parts before trouble- shooting.
  • Page 238 ELEC SIGNAL SYSTEM YP****** 4. Wireharness POOR CONNECTION S Check the connections of the entire signal system. Refer to “CIRCUIT SYSTEM WIRING DIA- Correct. GRAM” section. CONTINUITY Check condition of each of the signal sys- tem’s circuits. Refer to “SIGNAL SYSTEM CHECK” section. 8-30...

  • Page 239: Signal System Check

    ELEC SIGNAL SYSTEM YP806020 SIGNAL SYSTEM CHECK 1. If the horn fails to sound. NO CONTINUITY 1. HORN switch Refer to “CHECKING SWITCHES” section. Replace the left handlebar switch. CONTINUITY 2. Voltage S Connect the pocket tester (DC20 V) to the horn lead.
  • Page 240 ELEC SIGNAL SYSTEM YP806022 2. If the brake light fails to come on: NO CONTINUITY 1. Bulb and bulb socket Refer to “CHECKING SWITCHES” section. Replace the bulb and/or bulb socket. CONTINUITY NO CONTINUITY 2. Brake switch (Front/Rear) Refer to “CHECKING SWITCHES” section. Replace brake switch.
  • Page 241 ELEC SIGNAL SYSTEM YP806023 3. If the flasher light and/or turn indicator light fails to blink. NO CONTINUITY 1. Bulb and bulb socket Refer to “CHECKING SWITCHES” section. Replace the bulb and/or bulb socket. CONTINUITY NO CONTINUITY 2. Turn switch Refer to “CHECKING SWITCHES”...
  • Page 242 ELEC SIGNAL SYSTEM 5. Voltage S Connect the pocket tester (DC20 V) to the bulb socket connector. At flasher light (left) Tester (+) lead ! Chocolate lead Tester (–) lead ! Black terminal At flasher light (right) Tester (+) lead ! Dark green lead Tester (–) lead ! Black terminal S Turn the main switch to on.

  • Page 243: Checking Of Connections

    ELEC SIGNAL SYSTEM YP806027 4. If the fuel gauge fails to operate. 1. Fuel sender S Remove the fuel sender from the fuel tank. S Disconnect the fuel sender coupler from the wireharness. Connect the pocket tester ( 10) to the fuel sender coupler lead.
  • Page 244 ELEC SIGNAL SYSTEM 3. Fuel gauge S Connect the fuel sender to wireharness. NOTE: S Move the float to “UP” or “DOWN” Before reading the meter, stay put the float for more than three minutes respectively at “UP” or “DOWN”. S Turn the main switch to “ON”.

  • Page 245: Cooling System

    ELEC COOLING SYSTEM YP80700 COOLING SYSTEM CIRCUIT DIAGRAM 3 Main switch 4 Battery 5 Main fuse Fuse (fan) Thermo switch Fan motor Thermo meter Thermo unit 8-37...

  • Page 246: Troubleshooting

    ELEC COOLING SYSTEM YP****** TROUBLESHOOTING IF THE FAN MOTOR FAILS TO TURN. Procedure Check: 1. Fuse (Main, Fan) 4. Fan motor (inspection 2) 2. Battery 5. Thermo switch 3. Fan motor (inspection 1) 6. Wiring connection (entire cooling system) NOTE: D Remove the following parts before trouble- shooting.
  • Page 247 ELEC COOLING SYSTEM YP****** 4. Fan motor (inspection 1) S Disconnect the fan motor couplers. SCconnect the battery as shown. Battery (+) lead ! Blue terminal Battery (–) lead ! Black terminal DOES NOT MOVE S Check the fan motor operation. Replace fan motor.
  • Page 248 ELEC COOLING SYSTEM S Handle the thermo switch with special care. Never subject it to strong shocks or allow it to be dropped. Should it be dropped, it must be replaced. S Do not touch the thermo switch to the bottom of the heated vessel.
  • Page 249 ELEC COOLING SYSTEM YP807010 TROUBLESHOOTING IF THE WATER TEMPERATURE METER FAILS TO MOVE, WHEN ENGINE IS WARM Procedure Check: 1. Fuse (Main, Fan) 4. Thermo unit 2. Battery 5. Voltage 3. Main switch 6. Wiring connection (entire cooling system) NOTE: D Remove the following parts before trouble- shooting.
  • Page 250 ELEC COOLING SYSTEM YP****** 4. Thermo unit S Drain the coolant, and remove the thermo unit from the radiator. D Handle the thermo unit with special care. S Immerse the thermo unit in the cool- Never subject it to strong shocks or al- low it to be dropped.
  • Page 251 ELEC COOLING SYSTEM YP****** 6. Wiring connection POOR CONNECTION S Check the connections of the entire cooling system. Refer to “CIRCUIT DIAGRAM” section. Correct. CORRECT Replace the temperature gauge. 8-43...

  • Page 252: Auto Choke System

    ELEC AUTO CHOKE SYSTEM YP****** AUTO CHOKE SYSTEM CIRCUIT DIAGRAM 3 Main switch 4 Battery 5 Main fuse 8 Thermo switch (auto choke) 9 Auto choke Ignitor unit Engine stop switch 8-44...
  • Page 253 ELEC AUTO CHOKE SYSTEM YP****** TROUBLESHOOTING IF THE AUTO CHOKE FAILS TO OPERATE. Procedure Check: 1. Fuse (Main) 5. Thermo switch 2. Battery 6. Auto choke unit resistance 3. Main switch 7. Voltage 4. Engine stop switch 8. Wiring connection (entire auto choke system) NOTE: D Remove the following parts before trouble-...
  • Page 254 ELEC AUTO CHOKE SYSTEM YP****** 5. Thermo switch S Disconnect the thermo switch from the ra- diator. S Connect the pocket tester ( 1) to the thermo switch S Immerse the thermo switch in the coolant S Check the thermo switch for continuity. NOTE: Note temperatures while heating the water with the temperature gauge...
  • Page 255 ELEC AUTO CHOKE SYSTEM YP****** 6. Auto choke unit resistance S Disconnect the auto choke unit coupler from the wireharness. S Connect the pocket tester ( 1) to the auto choke unit coupler lead. Tester (+) lead ! Black terminal OUT OF SPECIFICATION Tester (–) lead ! Black terminal Auto choke unit resistance:...
  • Page 256 ELEC...

  • Page 257: Troubleshooting

    CHAPTER 9. TROUBLESHOOTING STARTING FAILURE/HARD STARTING ......FUEL SYSTEM ..........COMPRESSION SYSTEM .

  • Page 259: Chapter 9. Troubleshooting

    TRBL STARTING FAILURE/HARD STARTING SHTG EB90000 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.

  • Page 260: Ignition System

    TRBL POOR IDLE SPEED PERFORMANCE SHTG IGNITION SYSTEM Battery Ignition system D Improperly charged battery D Faulty ignitor unit D Faulty battery D Faulty pick up coil D Broken magneto woodruff key Fuse D Burnt out, improper connection Switch D Faulty main switch Spark plug D Improper plug gap D Faulty “ENGINE STOP”...

  • Page 261: Poor Medium And High Speed Performance

    TRBL POOR MEDIUM AND HIGH SPEED PERFORMANCE SHTG EB902000 POOR MEDIUM AND HIGH SPEED PERFORMANCE POOR MEDIUM AND HIGH SPEED PERFORMANCE Refer to “STARTING FAILURE/HARD STARTING” section. (Fuel system, electrical system, compres- sion system and valve train) Carburetor Air cleaner D Improperly adjusted fuel level D Clogged air cleaner element D Clogged main nozzle...

  • Page 262: Poor Speed Performance

    TRBL FAULTY CLUTCH SHTG YP****** FAULTY CLUTCH WHEN ENGINE IS RUN, SCOOTER DOES NOT RUN V belt POOR SPEED PERFORMANCE D Worn/bent/slipping V belt Cam, slider D Worn D Worn/damaged D Oily V belt Compression spring Roller weight D Damage D Worn/improper operation Gears Primary/secondary sheave...

  • Page 263: Overheating Or Over Cooling

    TRBL OVERHEATING OR OVER COOLING SHTG YP905000 OVERHEATING OR OVER COOLING OVERHEATING OVER COOLING Ignition system Cooling system D Improper spark plug gap D Faulty cooling fan D Improper spark plug heat range D Faulty thermostat DFaulty ignitor unit D Faulty thermo switch Fuel system D Improper carburetor setting D Improper fuel level adjustment...

  • Page 264: Faulty Brake

    TRBL FAULTY BRAKE/FRONT FORK MALFUNCTION SHTG YP906000 YP907000 FAULTY BRAKE FRONT FORK MALFUNCTION POOR BRAKING EFFECT OIL LEAKAGE D Bent, damaged or rusty inner tube Front brake D Worn brake pad D Damaged or cracked outer tube D Worn brake disc D Damaged oil seal lip D Air in brake fluid D Loose hexagon bolt...

  • Page 265: Instable Handling

    INSTABLE HANDLING/ TRBL STARTER MOTOR DOES NOT OPERATE SHTG YP908000 YP****** INSTABLE HANDLING STARTER MOTOR DOES NOT INSTABLE HANDLING OPERATE Handlebars STARTER MOTOR DOES NOT OPERATE D Loose handlebar tightening bolt Battery D Insufficient battery capacity Steering D Loose or overtightening steering nut D Faulty battery D Bent under bracket Fuse...

  • Page 266: Faulty Signal And Lighting System

    TRBL FAULTY SIGNAL AND LIGHTING SYSTEM SHTG YP909000 FAULTY SIGNAL AND LIGHTING SYSTEM HEADLIGHT DARK FLASHER BLINKS SLOWER D Improper bulb D Faulty flasher relay D Too many electric accesories D Insufficient battery capacity D Hard charging (nearly discharged) D Faulty rectifier/regulator D Improper bulb D Faulty battery D Faulty main and/or turn switch...
  • Page 267 YP250 WIRING DIAGRAM 1. A.C. magneto 2. Rectifier / regulator 3. Main switch 4. Main fuse 5. Battery 6. Starter relay 7 Starter motor 8 Thermo switch (auto choke) 9. Auto choke 10. Ignitor unit 11. Ignition coil 12. Spark plug 13.

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