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Yamaha YB50 Service Manual

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2002
YN50
5RN-AE1

SERVICE MANUAL

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Summary of Contents for Yamaha YB50

  • Page 1: Service Manual

    2002 YN50 5RN-AE1 SERVICE MANUAL...
  • Page 2 YN50 SERVICE MANUAL © 2002 Yamaha Motor España, S.A. First Edition, September 2002 All rights reserved. The reprinting or use of this material without the written authorisation of Yamaha Motor España, S.A is forbidden. Printed in Spain.
  • Page 3 WARNING This Manual was written by Yamaha Motor España, S.A. principally for the use of Yamaha/MBK agents and qualified mechanics. As it is not possible to give full mechanical instructions in a manual, it is presumed that the persons using the book to carry out the maintenance and repair of Yamaha/MBK motorcycles have a basic knowledge of the concepts and procedures inherent in the technology of motorcycle repair.
  • Page 4 HOW TO USE THIS MANUAL FORMAT OF THIS MANUAL This manual is composed of chapters on the main subject categories (See “Illustrated Symbols”). First heading : This is a chapter with a symbol at the top right-hand side of each page. Second heading : This title appears at the top of each page to the left of the chapter symbol.
  • Page 5 ILLUSTRATED SYMBOLS (See illustration) SPEC Illustrated symbols are designed as INFO tabs to be followed with the thumb to indicate the chapter number and the index. General information INSP/ Specifications Periodic inspection and adjustment General overhaul of the engine Carburation Chassis Electrical system CARB...
  • Page 6 INDEX GENERAL INFORMATION GEN/ INFO SPECIFICATIONS SPEC PERIODIC INSPECTION INSP AND ADJUSTMENTS GENERAL OVERHAUL OF ENGINE CARBURATION CARB CHASSIS CHAS ELECTRICAL SYSTEM ELEC TROUBLESHOOTING TRBL SHTG...
  • Page 7 GEN/ INFO...

  • Page 8: Table Of Contents

    GEN/ INFO CHAPTER 1 GENERAL INFORMATION IDENTIFICATION OF THE SCOOTER…………………………………………1-1 SERIAL NUMBER OF THE FRAME …………………………………………1-1 ENGINE SERIAL NUMBER……………………………………………………1-1 IMPORTANT INFORMATION …………………………………………………1-2 CHANGE OF ALL PARTS ……………………………………………………1-2 OIL SEALS AND O-RINGS ……………………………………………………1-2 SEALING WASHERS/PLATE AND KEYS……………………………………1-2 BEARING AND OIL SEALS …………………………………………………1-2 CIRCLIPS ………………………………………………………………………1-3 SPECIAL TOOLS …………………………………………………………………1-3 FOR SERVICING THE ENGINE ………………………………………………1-3...

  • Page 9: General Information

    GEN/ IDENTIFICATION OF THE SCOOTER INFO GENERAL INFORMATION SCOOTER IDENTIFICATION FRAME SERIAL NUMBER The serial number of the frame is stamped on the steering head pipe. Frame VTL5AD according standard EU0 Frame VTLSA15 according standard EU1 Frame VTLSA19 according Mofa Version ENGINE SERIAL NUMBER The engine serial number is stamped on...

  • Page 10: Important Information

    GEN/ IMPORTANT INFORMATION INFO IMPORTANT INFORMATION CHANGE OF ALL PARTS 1. We recommend that original Yamaha parts are used as spare parts. Use the oil and/or grease recommended by Yamaha for assembly and adjustment. GASKETS, OIL SEALS AND O-RINGS 1. All gaskets and o-rings should be replaced when the engine is overhauled and repaired.

  • Page 11: Circlips

    IMPORTANT INFORMATION / GEN/ SPECIAL TOOLS INFO CIRCLIPS 1. All circlips should be carefully inspected before assembly. Always replace circlips of the piston drum after use. Replace defor- med circlips. When installing a circlip ensure that the corner with the sharp edge is placed in the opposing direction to the thrust it receives.
  • Page 12 GEN/ SPECIAL TOOLS INFO 4. Pulley wheel clamp (90890-01701) 5. Clutch spring compressor (90890-01337) 6. Crankshaft installer crucible... (90890-01274) 7. Crankshaft installer bolt... (90890-01275)

  • Page 13: For Servicing The Chassis

    GEN/ SPECIAL TOOLS INFO 8. Adaptor (M10)... (90890-01277) 9. Spacer... (90890-01411) FOR SERVICING THE CHASSIS 1. T-shaped handle 2... (90890-01326) Shock absorber rod support... (90890-01294-A) 2. Counterbalance for insertion of fork seals (90890-01184) 3. Accessory for insertion of fork seals (90890-01186)

  • Page 14: For Electrical Components

    GEN/ SPECIAL TOOLS INFO 4. Steering nuts wrench (90890-01403) FOR ELECTRICAL COMPONENTS 1. Pocket tester (90890-03112) 2. Ignition tester (90890-06754)
  • Page 16 SPEC...
  • Page 17 SPEC CHAPTER 2 SPECIFICATIONS GENERAL SPECIFICATIONS …………………………………………………2-1 MAINTENANCE SPECIFICATIONS ……………………………………………2-3 ENGINE …………………………………………………………………………2-3 CHASSIS ………………………………………………………………………2-5 ELECTRICAL SYSTEM ………………………………………………………2-6 CABLE ROUTING ……………………………………………………………2-7...

  • Page 18: General Specifications

    Compression ratio 11.6:1 5AD 10.2:1 SA15 11:1 SA19 Starter system Electrical and pedal kickstart Lubrication system: Yamaha autolubrication Type or grade of oil: Engine oil 2-stroke air-cooled engine oil Transmission oil SE type 10W30 SAE engine oil Oil capacity: Oil sump (engine oil) 1.2 L...
  • Page 19 SPEC GENERAL SPECIFICATIONS Model YN50R Brakes: Front brake type Disc brake Operation Right-hand operation Rear brake type Drum brake Operation Left-hand operation Suspension: Front suspension Telescopic fork Rear suspension Balancing unit Shock absorber: Front shock absorber Spring/oil shock absorber Rear shock absorber Spring/oil shock absorber Travel of wheels: Travel of front wheel...

  • Page 20: Maintenance Specifications

    SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Model YN50R Cylinder head: Warping limit 0.02 mm * The lines indicate the measurement Cylinder: Internal diameter 39.993 ~ 40.012 mm <Limit> <40.1 mm> Taper limit 0.05 mm Eccentricity limit 0.01 mm Piston: Piston size 39.952 ~ 39.972 mm Measurement point 5 mm...
  • Page 21 SPEC MAINTENANCE SPECIFICATIONS Model YN50R Automatic centrifugal clutch: Thickness of clutch shoe 2 mm <Limit> <1 mm> Free length of clutch shoe 29.9 mm spring Clutch revolutions 3.600±250 rpm Clutch binding revolutions 5.600±400 rpm Transmission: Main axle deflection limit 0.08 mm Drive axle deflection limit 0.08 mm Choke handle:...

  • Page 22: Chassis

    SPEC MAINTENANCE SPECIFICATIONS CHASSIS Model YN50R Steering system: Steering bearing type Ball bearing Front suspension: Travel of front shock absorber 70 mm Free length of shock absorber spring 226 mm <Limit> Spring/stroke ratio 1.12 Kgf/mm 1.78 Kgf/mm Oil capacity 45 cm ±1 Oil grade 10 W shock absorber oil or equivalent...

  • Page 23: Electrical System

    SPEC MAINTENANCE SPECIFICATIONS ELECTRICAL SYSTEM Model YN50R Ignition system: Type DC-C.D.I. Ignition distribution (A.P.M.S.) 14*/5.000 r/min C.D.I.: 400 ~ 600 Ω a 20 Harnessing coil resistance (colour) C (68 (Black/Red-Black) Ignition coil: Spark plug electrodes gap 6.0 mm 0.56 ~ 0.84 Ω at 20 °C Primary coil resistance Secondary coil resistance 5,68 ~ 8,52 KΩ...

  • Page 24: Cable Routing

    SPEC CABLE ROUTING CABLE ROUTING Front brake pipe Insert the seat closing cable through the Rear brake cable frame orifice Rear brake calliper Connect the oil tube to the carburettor Rear mudguard Splice the fuel pipe to the cock Rear warning light Splice the fuel pipe to the carburettor Vacuum tube Fuel pipe...
  • Page 25 SPEC CABLE ROUTING Rectifier/Regulator Splice the electrical installation to the frame Main switch Splice the oil pipe to the tank Fuel level measurer Connect the oil pipe to the pump Horn Splice the installation to the frame Ignition coil Tighten the earth cable and the ignition coil Spark plug cable together Oil level sensor...
  • Page 26 SPEC CABLE ROUTING Front break switch Do not pinch the accelerator cable when Electrical installation assembling the handlebar covers Accelerator cable tensioner. Cover after Intermittent relay adjusting Speedometer assembly Connect the brake switch cables in this area Accelerator cable Do not pass the brake pipe through the flan- Rear brake cable Choke cable Front brake hose...
  • Page 27 INSP...
  • Page 28 INSP CHAPTER 3 PERIODIC INSPECTION AND ADJUSTMENTS INTRODUCTION/PERIODIC MAINTENANCE/LUBRICATION INTERVALS …3-1 REAR BODYWORK AND FOOTREST ………………………………………3-2 REMOVAL ………………………………………………………………………3-2 INSTALLATION …………………………………………………………………3-3 MUDGUARDS, LOWER COVER AND FRONT PANEL ……………………3-4 REMOVAL ………………………………………………………………………3-5 INSTALLATION …………………………………………………………………3-5 HANDLEBAR COVERS …………………………………………………………3-5 REMOVAL ………………………………………………………………………3-5 INSTALLATION …………………………………………………………………3-5 ENGINE ……………………………………………………………………………3-6 ADJUSTMENT OF ENGINE IDLING …………………………………………3-6 ADJUSTMENT OF FREE PLAY OF TROTTLE CABLE ……………………3-7 SPARK PLUG INSPECTION …………………………………………………3-8...
  • Page 29 √ √ and switches • Adjust headlight beam. • Since these items require special tools, data and technical skills, have a Yamaha/MBK dealer perform the ser- vice. NOTE: • The air filter needs more frequent service if you are riding in unusually wet or dusty areas.

  • Page 30: Rear Bodywork And Footrest

    INSP REAR BODYWORK AND FOOTREST REAR BODYWORK AND FOO- TREST REMOVAL 1. Raise the seat 2. Remove: • Seat 3. Remove: • Battery cover 4. Remove: • Rear cover 5. Remove: • Side covers NOTE: When the side covers are being removed unhook them from the catches and slide them outwards.

  • Page 31: Installation

    INSP REAR BODYWORK AND FOOTREST 6. Remove: • Footrest INSTALLATION When the foot support panel and the rear cover are being installed, reverse the removal process. Remember the following points. 1. Install: • Side covers NOTE: • Match up the support and hole and then apply pressure.

  • Page 32: Removal

    INSP REAR BODYWORK, MUDGUARDS REAR BODYWORK, MUD- GUARDS REMOVAL 1. Remove: • Main switch cover. Turn the cover to the left and pull upwards. 2. Remove: • Upper screws in ignition key panel • Rear fairing assembly and headlight NOTE: Disconnect the headlight cable and indica- tors.

  • Page 33: Handlebar Covers

    INSP HANDLEBAR COVERS HANDLEBAR COVERS REMOVAL 1. Remove: • Front handlebar cover • Rear handlebar cover INSTALLATION Reverse the removal procedure. Remember the following points. 1. Install: • Front handlebar cover • Rear handlebar cover NOTE: When installing the rear cover, check that the speedometer cables goes through its hou- sing.

  • Page 34: Engine

    INSP ADJUSTMENT OF ENGINE IDLING ENGINE ADJUSTMENT OF ENGINE IDLING 1. Tighten: • Pilot air screw Turn the pilot air screw inwards until it seats itself lightly. 2. Loosen: • Pilot air screw. Unscrew it from its lightly seated posi- tion.
  • Page 35 AJUSTE DEL JUEGO LIBRE DEL INSP CABLE DEL ACELERADOR ADJUSTMENT OF FREE PLAY OF THROT- TLE CABLE 1. Check: • Free play of throttle cable Outside specified value Adjust. Free play 2 ~ 5 mm Steps for adjusting the free play of the throttle cable: NOTE: Before adjusting the free play of the throttle,...

  • Page 36: Spark Plug Inspection

    INSP SPARK PLUG INSPECTION SPARK PLUG INSPECTION 1. Inspect: • Incorrect type of spark plug Replace Standard spark plug (5AD y SA15) BR8HS/N.G.K. for SA19 BRP4HS/N.G.K. 2. Inspect: • Electrode Worn/Damaged Replace • Insulator Abnormal colour Replace The normal colour is a light to medium coffee colour.

  • Page 37: Inspection Of Engine Oil Level

    INSP INSPECTION OF ENGINE OIL LEVEL INSPECTION OF ENGINE OIL LEVEL 1. Inspect: • Engine oil level Low oil level Add sufficient oil. Oil indicator light “OIL CAUTION” Visual inspection steps for engine oil level Place main switch in position ( The “OIL CAUTION”...

  • Page 38: Change Of Transmission Oil

    CHANGE OF TRANSMISSION OIL / INSP CLEANING AIR FILTER CHANGE OF TRANSMISSION OIL 1. Remove: • Drainage bolt Drain the transmission oil. • Oil refill cap 2. Inspect: • Gasket (drainage screw) • O-ring (refill cap) Damaged Change 3. Install: •...
  • Page 39 ATTENTION: Do not wring the filter when drying it. • Apply oil for foam air filters or YAMAHA 2T engine oil or equivalent oil for 2 stroke air- cooled engines. • Wipe off the excess oil.

  • Page 40: Chassis

    ADJUSTMENT OF FREE PLAY OF FRONT BRAKE LEVER / INSP ADJUSTMENT OF FREE PLAY OF REAR BRAKE LEVER / INSPECTION OF BRAKE PADS CHASSIS ADJUSTMENT OF FREE PLAY OF FRONT BRAKE LEVER 1. Check: • Free play of the front brake lever. 2 ~ 5 mm s WARNING The soft or spongy feeling of the brake lever...

  • Page 41: Inspection Of Brake Shoes

    INSPECTION OF BRAKE SHOES / INSP INSPECTION OF BRAKE FLUID LEVEL NSPECTION OF BRAKE SHOES 1. Activate the brake lever 2. Inspect: • Wear indicator Indicator on wear limit line Change the brake shoes. INSPECTION OF BRAKE FLUID LEVEL NOTE: Place the scooter upright when inspecting the fluid level.

  • Page 42: Air Bleeding (Hydraulic Brake System)

    AIR BLEEDING (HYDRAULIC BRAKE SYSTEM) / INSP STEERING ADJUSTMENT AIR BLEEDING (HYDRAULIC BRAKE SYS- TEM) 1. Bleed: • Brake fluid Steps for air bleeding: a. Add the appropriate amount of brake fluid to the sump. b. Install the diaphragm. Take care not to spill fluid or to let the sump overflow.

  • Page 43: Inspection Of Tyres

    INSP INSPECTION OF TYRES Steps for tightening the steering nut: 1. Tighten the lower ring to 3.8 m • kg. 2. Loosen the lower ring nut 1/2 of a turn and tighten to 0.65 m • kg. 3. Check the steering for smooth operation. 4.

  • Page 44: Wheel Inspection

    WHEEL INSPECTION / INSPECTION OF REAR FORK / INSP REAR SHOCK ABSORBER INSPECTION WHEEL INSPECTION 1. Inspect: • Wheels damaged/warped Replace. s WARNING: Never try to make even the smallest repairs on wheels. INSPECTION OF REAR FORK 1. Inspect: • Rear fork Bent/Damaged Fork bar Change...

  • Page 45: Electrical System

    INSP BATTERY INSPECTION ELECTRICAL SYSTEM BATTERY INSPECTION 1. Remove: • Battery cover See “REAR BODYWORK” section 2. Inspect: The fluid level between the maximum and minimum marks. Incorrect Refill ATTENTION: Add only distilled water; tap water contains minerals which are damaging to the battery. 3.
  • Page 46 INSP BATTERY INSPECTION Change the battery in the following cases: • When the voltage does not reach the speci- fied value and bubbles do not appear, even after several hours of charging. • When one or more of the trays become sulphated, which can be seen when the plates become white are material accumu- lates on the bottom.

  • Page 47: Inspection Of Fuses

    INSP INSPECTION OF FUSES INSPECTION OF FUSES 1. Remove: • The battery cover See the “FRONT BODYWORK” section 2. Inspect: • Fuse Defective Replace Steps to be taken for blown fuses: • Disconnect the ignition and circuit. • Install a new fuse of the correct amperage. •...

  • Page 48: Adjustment Of Headlamp Beam

    ADJUSTMENT OF HEADLAMP BEAM / INSP REPLACEMENT OF HEADLAMP BULB ADJUSTMENT OF HEADLAMP BEAM 1. Adjust: • Headlamp (vertically) To raise the beam Turn the screw inwards To lower the beam Turn the screw outwards REPLACEMENT OF HEADLAMP BULB 1. Remove: •...
  • Page 51 CHAPTER 4 GENERAL OVERHAUL OF ENGINE ENGINE REMOVAL ………………………………………………………………4-1 REAR COVER AND FOOTREST PANEL ……………………………………4-1 CARBURETTOR ………………………………………………………………4-1 SILENCER ASSEMBLY ………………………………………………………4-1 CABLES AND TUBES …………………………………………………………4-2 REMOVAL OF ENGINE ………………………………………………………4-3 DISASSEMBLY THE ENGINE …………………………………………………4-4 REAR WHEEL …………………………………………………………………4-4 CENTRAL SUPPORT …………………………………………………………4-4 CYLINDER HEAD AND CYLINDERS ………………………………………4-4 PISTON PINS AND PISTON …………………………………………………4-4 KICK STARTER…………………………………………………………………4-5 PRIMARY PULLEY WHEEL …………………………………………………4-6...

  • Page 52: General Overhaul Of Engine

    ENGINE REMOVAL GENERAL OVERHAUL OF THE ENGINE REMOVAL OF ENGINE REAR BODYWORK AND FOOTREST 1. Remove: • Side covers (left and right) • Rear cover • Footrest panel See section in chapter 3 “REAR BODYWORK AND FOOTREST” CARBURETTOR 1. Remove: •...
  • Page 53 ENGINE REMOVAL CABLES AND PIPES 1. Remove: • Oil pipe from side of oil pump. NOTE: Position oil pipe so that the oil does not spill out. 2. Remove: • Bolts (trunk) • Overflow bowl rivets NOTE: To remove the overflow bowl, take off the fuel and oil caps and replace them immediately after removing the bowl.
  • Page 54 ENGINE REMOVAL ENGINE REMOVAL 1. Remove: • Rear shock absorber screw (lower) 2. Remove: • Engine assembly screw • Engine Lift the frame and remove the engine 3. Place the frame on a suitable support...

  • Page 55: Disassembly The Engine

    DISASSEMBLY THE ENGINE DISASSEMBLY ENGINE REAR WHEEL 1. Remove: • Rear wheel • Brake shoes • Flat washer CENTRAL STAND 1. Remove: • Clip • Rubber washer • Axle • Clasp • Spring • Central stand CYLINDER HEAD AND CYLINDER 1.
  • Page 56 DISASSEMBLY THE ENGINE 2. Remove: • Piston pin • Piston • Piston pin bearing ATTENTION: Do not use a hammer to take out the pis- ton pin. KICKSTART SYSTEM 1. Remove: • Kickstart pedal • Crankcase cover (left) 2. Remove: •...

  • Page 57: Primary Pulley Wheel

    DISASSEMBLY THE ENGINE PRIMARY PULLEY WHEEL 1. Remove: • Fan 2. Remove: • Nut (primary pulley wheel) NOTE: When the nut is loosened (primary pulley wheel), support the magnetic flywheel using the engine wheel support tool Engine wheel holding tool: 90890-01235 3.

  • Page 58: Starter System

    DISASSEMBLY THE ENGINE 3. Apply: • Pulley wheel clamp • Nut spanner (41MM) Pulley wheel clamp: 90890-01701 4. Loosen: • Clutch positioning nut ATTENTION: Do not remove the clutch positioning nut yet. 5. Apply: • Clutch spring compressor Clutch spring compressor: 90890-01337 6.

  • Page 59: Transmission

    DISASSEMBLY THE ENGINE TRANSMISSION 1. Remove: • Transmission box cover • Gasket • Centring devices NOTE: Before proceeding to disassemble the trans- mission cap, empty the oil. 2. Remove: • Main axle • Drive axle • Flat washer • Conical spring washer 3.

  • Page 60: Autolubrication Pump

    DISASSEMBLY THE ENGINE AUTOLUBRICATION PUMP 1. Remove: • Autolubrication pump 2. Remove: • Elastic circlip • Pump drive gearing • Pin • Elastic circlip 3. Remove: • Carburettor gasket • Reed valve • Reed valve gasket CRANKCASE AND CRANKSHAFT 1. Remove: •...
  • Page 61 DISASSEMBLY THE ENGINE 3. Remove: • Crankcase (right) While pressure is applied, strike alternati- vely on the engine assembly hubs. 4. Apply: • Crankcase separation tool Crankcase separation tool 90890-01135 5. Remove: • Crankshaft 4-10...

  • Page 62: Inspection And Repair

    INSPECTION AND REPAIR INSPECTION AND REPAIR CYLINDER HEAD 1. Eliminate: • Carbon deposits Use a rounded scraper 2. Inspect: • Cylinder head warping. Outside specified value Rectify Steps for measuring warping and rectifica- tion: • Join a straight edge and a thickness cali- bration on the cylinder head •...
  • Page 63 INSPECTION AND REPAIR 4. Remove: • Cracking marks and carbon deposits on piston sides. 5. Inspect: • Piston wall Wear/striping/damage Change 6. Measure: • Cylinder piston clearance Steps for measuring the clearance of the cylinder piston First step: • Measure the lower diameter “C” with a dial gauge.

  • Page 64: Piston Rings

    INSPECTION AND REPAIR Size of the piston P Standard 39.952 ~ 39.997 mm 1st Clearance 40.25 mm 2st Clearance 40.50 mm • If this is outside the specified value change the piston and the set of rings. Third step: • Calculate the clearance of the piston to the cylinder using the following formula: Clearance of piston to cylinder = Inner diameter of cylinder “C”...

  • Page 65: Piston Pin And Piston Pin Bearing

    INSPECTION AND REPAIR 3. Measure: • Gap between ends Outside specified value Change set rings. Use a thickness gauge Standard Limit Top ring 0.15~0.35 mm 0.60 mm Second ring 0.15~0.35 mm 0.60 mm Measurement point 20 mm (0.8 in) 4. Clearance of piston rings: The size of the rings is not stamped on its upper part.

  • Page 66: Kick Starter

    INSPECTION AND REPAIR 4. Inspect: Bearing (piston pin) Pitting/Damage Change KICKSTART 1. Inspect: • Pedal gear teeth • Pedal pinion gear teeth Burrs/Spalling/Non-uniformity/Wear Change 2. Inspect: • Locking bolt(pedal pinion gear and one way clutch) Rounded edges/Wear Change 3. Measure: •...

  • Page 67: Transmission

    INSPECTION AND REPAIR TRANSMISSION 1. Inspect: • Drive axle • Main axle • Secondary pulley wheel axle Burrs/Spalling/Non-uniformity/Wear Change 2. Inspect: • Secondary pulley wheel axle bearing • Main axle bearing • Drive axle bearing Pivot the inner guide of the bearing. Excessive play/Non-uniformity Change Pitting/Damage...

  • Page 68: Primary Pulley Wheel

    INSPECTION AND REPAIR Deflection limit “C”: 0.03 mm Clearance on big end side “D”: 0.2 ~ 0.5 mm Free play at small end “F”: 0.4 ~ 0.8 mm 2. Inspect: • Bearings (crankshaft) Pivot the inner bea- ring guide. Excessive play/Non-uniformity Change Pitting/Damage...

  • Page 69: Secondary Pulley Wheel

    INSPECTION AND REPAIR SECONDARY PULLEY WHEEL 1. Inspect: • Secondary fixed pulley wheel • Secondary sliding pulley wheel Striping/Cracks/Damage Change set. • Oil seal Damage Change. 2. Inspect: • Turning cam groove • Guide pin Wear/Damage Change set. • O-ring Damaged Change.

  • Page 70: Trapezoidal Belt

    INSPECTION AND REPAIR 6. Inspect: • Clutch shoes shiny parts Polish with sand paper. NOTE: After using sand paper, clean the polished particles with a cloth. 7. Measure: • Thickness of clutch shoe Outside specified value Change Thickness of clutch shoe 2.0 mm <Wear limit>...
  • Page 71 INSPECTION AND REPAIR 2. Inspect: • Starter wheel gear teeth • Intermediate gear teeth Burrs/Spalling/Non-uniformity/Wear Change • Bearing (starter wheel gear) Pitting/Damage Change 4-20...

  • Page 72: Assembly And Adjustment Of Engine

    ASSEMBLY AND ADJUSTMENT OF ENGINE ASSEMBLY AND ADJUSTMENT OF ENGINE CRANKSHAFT AND CRAKCASE Oil seal Crankshaft pin Oil seal catch Connecting rod Crankcase (right) Crankcase (left) Centring device Bearing Bearing Engine mounting spacer Crankcase (right) Crankcase (left) Bearing Oil seal CRANKSHAFT A: 37.90 ~ 37.95 mm C: 0.03 mm...

  • Page 73: Crankshaft And Crankcase

    • Crankshaft (in left crankcase) 3. Install: • Centring device • Engine mounting spacer 4. Apply: • Yamaha N.º 1215 adhesive on the corresponding surfaces of both halves of the crankcase Yamaha N. 1215 adhesive: 90890-85505 5. Place: • Crankshaft installation tool...

  • Page 74: Autolubrication Pump

    ASSEMBLY AND ADJUSTMENT OF ENGINE AUTOLUBRICATION PUMP AND MAGNETIC FLYWHEEL Oil outlet pipe Flat washer Oil pipe Rotor assembly Bushing Charge coil Autolubrication pump Lighting coil O-ring Harnessing coil Elastic circlip Stator plate Oil pump drive gear Oil seal Gasket 4-23...

  • Page 75: Flywheel Magnet

    ASSEMBLY AND ADJUSTMENT OF ENGINE AUTOLUBRICATION PUMP 1. Install: • Elastic circlip • Pin • Pump drive gear • Elastic circlip 2. Apply: • Grease with lithium soap base (on the o-ring 3. Install: • Autolubrication pump Screw (autolubrication pump) 0.4 m •...

  • Page 76: Transmission

    ASSEMBLY AND ADJUSTMENT OF ENGINE TRANSMISSION Circlip Secondary pulley wheel axle Bearing Bearing Oil seal Centring device Drive axle Seal Bearing Transmission box cover Main axle Bearing Conical spring washer Oil seal Flat washer 4-25...
  • Page 77 ASSEMBLY AND ADJUSTMENT OF ENGINE 6. Tighten: • Nut (flywheel magneto) Use the engine wheel support tool Engine wheel support tool 90890-01235 Flywheel nut 4.3 m • kg TRANSMISSION 1. Apply: • SE engine oil type 10W30 (on the transmission box cover bearing) 2.
  • Page 78 ASSEMBLY AND ADJUSTMENT OF ENGINE STARTER SYSTEM Bushing Axle Bearing Flat washer Starter wheel gear Intermediate gear Starter clutch O-ring Plate Starter engine 4-27...

  • Page 79: Starter Motor

    ASSEMBLY AND ADJUSTMENT OF ENGINE STARTER SYSTEM 1. Install: • Bushing • Bearing • Starter wheel gear • Starter clutch NOTE: • Apply grease with a lithium soap base on the bearing • Apply molybdenum disulphide oil on the pin (starter clutch) 2.

  • Page 80: Secondary Pulley Wheel

    ASSEMBLY AND ADJUSTMENT OF ENGINE SECONDARY AND PRIMARY PULLEY WHEEL Secondary sliding pulley Shim wheel Clutch drum Trapezoidal belt Clutch plate Sliding primary pulley wheel Guide pin Shoe spring Rollers Secondary fixed pulley wheel Clutch spring Runner Conical washer Spring seat One-way clutch Oil seal Washer...

  • Page 81: Starter Pedal

    ASSEMBLY AND ADJUSTMENT OF ENGINE KICKSTART PEDAL Pedal axle Return spring Bushing Flat washer Elastic retainer Starter pedal Spring Pedal pinion gear 10 Nm (1.0 m • kg) 150 ~ 250 g 4-30...
  • Page 82 ASSEMBLY AND ADJUSTMENT OF ENGINE SECONDARY PULLEY WHEEL When assembling the secondary pulley wheel, reverse the disassembly procedure. Remember the following points: 1. Apply: • Assembly grease (in the sliding/fixed pulley wheel) 2. Install: • Sliding pulley wheel NOTE: Take care that the lips of the oil seals do not turn when the pulley wheel is installed.
  • Page 83 ASSEMBLY AND ADJUSTMENT OF ENGINE 7. Install: • Conical pin • Crankcase cover seal • Secondary pulley wheel assembly • Clutch drum 8. Tighten: • Nut (secondary pulley wheel) Use the pulley wheel support Pulley wheel clamp 90890-01701 Clutch drum nut 4.0 m •...
  • Page 84 ASSEMBLY AND ADJUSTMENT OF ENGINE 6. Install: • Shim • Primary fixed pulley wheel • Washer • One-way clutch • Conical spring washer • Nut 7. Tighten: • Nut (primary pulley wheel) Primary pulley wheel nut 3,3 m • kg NOTE: When the nut is tightened (primary pulley wheel), support the magnetic flywheel using...
  • Page 85 ASSEMBLY AND ADJUSTMENT OF ENGINE 2. Hook on: • Return spring (on pedal gear and hub) 3. Install: • Pedal pinion gear 4. Install: • Crankcase cover Screw (crankcase cover) 7 Nm (0.7 m • kg) 5. Install: • Kickstart pedal Kickstart pedal 0.9 m •...
  • Page 86 ASSEMBLY AND ADJUSTMENT OF ENGINE PISTON, CYLINDER AND CYLINDER HEAD Carburettor gasket Cylinder seal Reed valve Piston rings Gasket Piston Cylinder head Piston pin Cylinder head gasket Circlips Cylinder Bearing SPARK PLUG CLEARANCE FROM PISTON TO MANUFACTURER/TYPE: CYLINDER: NKG/BR7HS 0.034 ~ 0.047 mm GAP BETWEEN ELECTRODES Limit: 0.1 mm 0.06 ~ 0.7 mm...

  • Page 87: Piston And Piston Pin

    ASSEMBLY AND ADJUSTMENT OF ENGINE PISTON AND PISTON PIN 1. Apply: • Engine oil (in the crankshaft bearing, big end bea- ring, small end bearing, piston pin, piston ring grooves and piston skirt areas.) 2. Install: • Reed valve gasket •...
  • Page 88 ASSEMBLY AND ADJUSTMENT OF ENGINE 3. Install: • Cylinder NOTE: Install the cylinder with one hand while com- pressing the piston rings with the other. 4. Install: • Cylinder head gasket (new gasket) 5. Install: • Cylinder head • Spark plug •...

  • Page 89: Engine Assembly

    ASSEMBLY AND ADJUSTMENT OF ENGINE ASSEMBLY OF ENGINE When the engine is being assembled, reverse the removal procedure 1. Install: • Engine assembly bolt • Rear shock absorber bolt (lower) Engine assembly bolt 8.4 m • kg Rear shock absorber bolt (lower) 1.8 m •...
  • Page 90 ASSEMBLY AND ADJUSTMENT OF ENGINE 6. Install: • Silencer • Fan cover Bolt (silencer) 2.6 m • kg Bolt (exhaust pipe) 0.9 m • kg 7. Apply: • Transmission oil. See chapter 3 section - “CHANGING TRANSMISSION OIL”. 8. Adjust: •...
  • Page 91 CARB...
  • Page 92 CARB CHAPTER 5 CARBURETOR CARBURETOR ……………………………………………………………………5-1 REMOVING THE CARBURETOR ……………………………………………5-2 DISASSEMBLING THE CARBURETOR ……………………………………5-2 CHECKING THE CARBURETOR ……………………………………………5-3 ASSEMBLING THE CARBURETOR …………………………………………5-5 CHECKING THE AUTOCHOKE UNIT ………………………………………5-6 INSTALLING THE CARBURETOR……………………………………………5-7 FUEL COCK ………………………………………………………………………5-7 CHECKING THE FUEL COCK ………………………………………………5-7 REED VALVE ………………………………………………………………………5-8 REMOVING THE REED VALVE ………………………………………………5-8 CHECKING THE REED VALVE ………………………………………………5-8 INSTALLING THE REED VALVE………………………………………………5-9...

  • Page 93: Carburetor

    CARB CARBURETOR EAS00480 CARBURETOR CARBURETOR Throttle valve spring Pilot jet Spring catch Float Throttle valve Float gasket Jet needle Drain screw Pilot air screw Needle valve Throttle stop screw Float chamber Needle jet Autochoke unit Main jet carburetor dell’orto carburetor gurtner...

  • Page 94: Removing The Carburetor

    CARB CARBURETOR REMOVING THE CARBURETOR 1. Remove: • air filter box • helmet box Refer to “REAR BODYWORK, MUD- GUARD” in chapter 3 2. Drain: • fuel (from drain screw 3. Disconnect: • autochoke lead coupler • fuel hose • vacuum hose •...

  • Page 95: Checking The Carburetor

    CARB CARBURETOR 4. Remove: • throttle stop screw (with spring, washer and o-ring) • pilot air screw (with spring) 5. Remove: • spring seat • jet needle • throttle valve • throttle valve spring EAS00485 CHECKING THE CARBURETOR 1. Check: •...
  • Page 96 CARB CARBURETOR 4. Check: • throttle valve Wear/Damage Change 5. Check: • throttle valve displacement Irregular movement/Catches Change Insert the throttle valve in the body and check its displacement. 6. Check: • throttle stop screw • pilot air screw • jet needle •...

  • Page 97: Assembling The Carburetor

    CARB CARBURETOR NOTE: The arm of the float should be supported on the valve without compressing it. • If the height of the float is not within the spe- cified limits, inspect the valve and its seat. • Substitute both parts if any part of them is worn.

  • Page 98: Checking The Autochoke Unit

    CARB CARBURETOR EAS00503 CHECKING THE AUTOCHOKE UNIT NOTE: When checking the autochoke unit, the ambient temperature must be lower than 45°C (113°F). 1. Remove: • carburetor 2. Check: • autochoke unit a. Connect a 3.3 mm hose to the starter air passage and blow into the hose.

  • Page 99: Installing The Carburetor

    CARB CARBURETOR/ FUEL COCK EAS00492 INSTALLING THE CARBURETOR 1. Adjust: • engine idling speed Engine idling speed 1.800 rpm Refer to “ADJUSTING HE ENGINE IDLING SPEED” in chapter 3. 2. Adjust: • throttle cable free play Throttle cable free play (at the flange of the throttle grip) 2 ~ 5 mm Refer to “ADJUSTING HE ENGINE IDLING...

  • Page 100: Reed Valve

    CARB REED VALVE REED VALVE REMOVING THE REED VALVE 1. Remove: • helmet box Refer to “REAR BODYWORK, MUD- GUARD” in chapter 3. • air filter box assembly 2. Remove: • carburetor See section “REMOVING THE CARBURE- TOR” 3. Remove: •...

  • Page 101: Installing The Reed Valve

    CARB REED VALVE 2. Measure: • valve stopper height Out of specification Adjust the stop- per/Replace the valve stopper. Height of valve stopper 6.0 ~ 6.4 mm 3. Measure: • clearance of reed valve Out of specification Replace the reed valve.
  • Page 102 CHAS...

  • Page 103: Chassis

    CHAS CHAPTER 6 CHASSIS FRONT WHEEL …………………………………………………………………6-1 EXTRACTION …………………………………………………………………6-2 INSPECTION……………………………………………………………………6-2 INSTALLATION …………………………………………………………………6-3 REAR BRAKE ……………………………………………………………………6-4 CHANGE OF BRAKE BLOCKS ………………………………………………6-5 DISASSEMBLY OF CALLIPER ………………………………………………6-6 INSPECTION AND REPAIR …………………………………………………6-7 ASSEMBLY OF CALLIPER ……………………………………………………6-7 ASSEMBLY OF PUMP ………………………………………………………6-8 REAR WHEEL ……………………………………………………………………6-9 EXTRACTION …………………………………………………………………6-10 INSPECTION …………………………………………………………………6-10 ASSEMBLY ……………………………………………………………………6-11 INSTALLATION ………………………………………………………………6-12...

  • Page 104: Front Wheel

    CHAS FRONT WHEEL CHASSIS FRONT WHEEL Wheel axle Tyre Speedometer gear unit Oil seal Bearing Spacer Spacer Washer Rim assembly TYRE SIZE: 120/70/12 RIM RUN-OUT LIMIT: Vertical: 1.0 mm Lateral: 1.0 mm WHEEL AXLE BEND LIMIT: 0.25 mm...

  • Page 105: Inspection

    CHAS FRONT WHEEL REMOVAL 1. Remove: • brake caliper • Axle • Wheel NOTE: Do not press the brake lever when the wheel is removed from the scooter, otherwise the brake blocks will be closed under force. INSPECTION 1. Measure: •...

  • Page 106: Installation

    CHAS FRONT WHEEL INSTALLATION Reverse the removal process. Bear in mind the following points. 1. Lubricate: • Front wheel axle • Bearings • Oil seal (edges) • Drive gear (speedometer) Recommended lubricant: Grease with lithium soap base 2. Install: • Speedometer gear unit NOTE: Ensure that the two projections in the gear unit are engaging with the flat surface of the...

  • Page 107: Front Brake

    CHAS FRONT BRAKE FRONT BRAKE Retaining bolt Master cylinder cap Bleed screw Diaphragm Calliper assembly Hose Block spring Brake pump assembly Pad set Assembly plate Piston seal Copper washer Piston Assembly bolt Brake disc Brake light switch cable TYPE OF BRAKE FLUID DOT 3 or 4 WEAR LIMIT OF BRAKE PADS: 0.8 mm...
  • Page 108 CHAS FRONT BRAKE EAS00583 REPLACING THE FRONT BRAKE PADS NOTE: When replacing the brake pads, it is not necessary to disconnect the brake hose or disassemble the brake caliper. 1. Remove: • brake pad cover • brake pad clip • brake pad pin •...
  • Page 109 CHAS FRONT BRAKE NOTE: The triangle mark a on the brake pad shim must point in the direction of disc rotation. e. Install new brake pads and a new brake pad spring NOTE: The arrow mark b of the brake pad spring must point in the direction of disc rotation.
  • Page 110 CHAS FRONT BRAKE CHECKING THE BRAKE HOSE 1. Check: • brake hoses cracks/damage/wear Replace. BRAKE HOSE ASSEMBLY s WARNING • All internal parts should be cleaned only in new brake fluid. • Internal parts should be lubricated with brake fluid when installed. Recommended brake fluid DOT 4 1.
  • Page 111 CHAS FRONT BRAKE CHECKING THE BRAKE DISC 1. Measure: • Deflection of brake disc Outside specified value Inspect run- out of wheel. If the wheel is in good condition, change the brake disc Maximum deflection 0.5 mm • Brake disc thickness Outside specified value Change Minimum thickness...
  • Page 112 CHAS REAR WHEEL REAR WHEEL Flat washer Brake shoe Valve Brake cam Shoe axle Flat washer Wear indicator Return spring Brake lever TYRE SIZE: 130/70-12 BRAKE DRUM WEAR LIMIT: 110.5 mm BRAKE SHOE WEAR LIMIT: 2.0 mm WHEEL RUN-OUT LIMIT: Vertical: 1.0 mm Lateral: 1.0 mm Change:...

  • Page 113: Rear Brake

    CHAS REAR WHEEL REMOVAL 1. Remove: • Exhaust pipe assembly 2. Loosen: • Rear axle nut NOTE: When the axle nut is loosened, apply rear brake. 3. Remove: • Rear wheel 4. Remove: • Rear brake cable • Brake shoes •...
  • Page 114 CHAS REAR WHEEL 5. Measure: • Thickness of brake shoes Outside specified value Change Brake shoes thickness 4.0 mm Limit: 2.0 mm 6. Inspect: • Drum brake iner surface Oil/Scratches Change 7. Measure • Drum brake inner diameter Out of specification Change Wear limit of brake drum 110.5 mm...

  • Page 115: Installation

    CHAS REAR WHEEL Bolt (cam lever): 0.7 m • kg 4. Install: • Flat washer • Brake cable INSTALLATION When installing the rear wheel, reverse the removal procedure. The following points should be remembered. 1. Install: • Rear wheel • Flat washer •...
  • Page 116 CHAS FRONT FORK FRONT FORK Front fork assembly (left) Oil seal Rubber cap Fork spring Restraining ring Sliding metal Restraining ring Shock absorber rod Return spring O-ring Dust guard Oil lock piece Retainer Outer tube Front fork assembly (right) FREE LENGTH OF FORK SPRING: LIMIT: LEFT 226 mm RIGHT 226 mm...

  • Page 117: Disassembly

    CHAS FRONT FORK REMOVAL 1. Place the scooter on its central stand and place an adequate support under the engi- 2. Remove: • Brake callipers Consult “FRONT BRAKE REMOVAL” sec- tion 3. Remove: • Front wheel See “FRONT WHEEL REMOVAL SEC- TION”...

  • Page 118: Inspection

    CHAS FRONT FORK 4. Remove: • Bolt (shock absorber rod) • Copper washer NOTE: Remove the bolt (shock absorber rod) while the shock absorber rod is held with the T- handle and a support T-handle: 90890-01326 Support: 90890-01294-A 5. Remove: •...

  • Page 119: Assembly

    CHAS FRONT FORK ASSEMBLY Reverse the disassembly procedure. Bear in mind the following points. NOTE: • When assembling the fork, ensure that the following new parts are used. • Oil seal • Mudguard • Sliding metal • Ensure that all components are clean before assembly.
  • Page 120 CHAS FRONT FORK 3. Install: • Retainer • Dust guard NOTE: Couple the retainer correctly on the groove of the outer tube 4. Fill : • Fork oil Each fork: 50 cm 10 W fork oil or equivalent after filling, slowly pump the fork to distribute the oil.

  • Page 121: Installation

    CHAS FRONT FORK INSTALLATION Reverse the removal procedure. The following points should be remembered 1. Install: • Front fork: • Stopper ring NOTE: Attach the stopper ring correctly on the inner tube groove. 2. Tighten: • Positioning bolt (lower bracket) Positioning bolt (inner lever arm) 30 Nm (3.0 m •...

  • Page 122: Handlebar And Steering

    CHAS HANDLEBAR AND STEERING HANDLEBAR AND STEERING Handlebar Lock washer Grip cap Center ring nut Throttle grip Rubber washer Throttle grip guide Lower ring nut Grip Bearing cover Upper bearing race Bolt Bearing cage Throttle cable Bearing race Brake cable Lower bracket Upper ring nut 6-19...

  • Page 123: Removal

    CHAS HANDLEBAR AND STEERING REMOVAL 1. Place the scooter on its central stand and place a suitable support under the engine. 2. Remove: • Front wheel See section “REMOVAL OF FRONT WHEEL” 3. Remove: • Mudguard • Front fairing See chapter 3,“FRONT BODYWORK, MUDGUARDS”...

  • Page 124: Inspection

    CHAS HANDLEBAR AND STEERING 8. Remove: • Upper ring nut Ring nut wrench for steering 90890-01403 s WARNING Support the steering axle so that it does not fall. 9. Remove: • Lock washer • Central ring nut • Rubber washer •...

  • Page 125: Installation

    CHAS HANDLEBAR AND STEERING NOTE: • Always change the bearing and the races together. • Change the mudguard whenever the stee- ring head is disassembled. ATTENTION: If the bearing race is not coupled correctly, the steering tube may be damaged. 3.
  • Page 126 CHAS HANDLEBAR AND STEERING 3. Tighten: • Steering nut Steps for tightening the steering nut: 1. Tighten the lower ring nut to 3.8 m•kg. 2. Loosen the lower ring nut 1/2 of a turn and tighten to 0.65 m•kg. 3. Check the steering for smooth operation. 4.
  • Page 127 CHAS HANDLEBAR AND STEERING 7. Install: • Brake pump NOTE: First tighten the upper bolt, then the lower bolt. Bolt (brake pump) 0.9 m • kg 8. Install: • Rear handlebar cover with speedometer • Front handlebar cover NOTE: Connect the speedometer cables, signalling and lighting systems.
  • Page 129 ELEC...
  • Page 130 ELEC CHAPTER 7 ELECTRICAL SYSTEM ELECTRICAL COMPONENTS …………………………………………………7-1 IGNITION AND STARTER SYSTEM……………………………………………7-3 CIRCUIT DIAGRAM ……………………………………………………………7-3 IGNITION AND STARTER CIRCUIT SYSTEM ………………………………7-4 TROUBLESHOOTING …………………………………………………………7-5 CHARGING SYSTEM …………………………………………………………7-10 CIRCUIT DIAGRAM …………………………………………………………7-10 LOCATION AND REPAIR OF FAULTS ……………………………………7-11 LIGHTING SYSTEM ……………………………………………………………7-13 CIRCUIT DIAGRAM …………………………………………………………7-13 LOCATION AND REPAIR OF FAULTS ……………………………………7-14 CHECKING OF LIGHTING SYSTEM ………………………………………7-15 SIGNALLING SYSTEM …………………………………………………………7-17...

  • Page 131: Electrical System

    ELEC ELECTRICAL COMPONENTS ELECTRICAL SYSTEM ELECTRICAL COMPONENTS Wire harness BATTERY Starter motor SPECIFIC GRAVITY: 1,280 CDI unit IGNITION COIL: Engine oil level gauge PRIMARY COIL RESISTANCE: Starter relay 0.56 ~ 0.84 Ω at 20 °C (68 °F) Fuel level gauge SECONDARY COIL RESISTANCE: Battery 5.7 ~ 8.5 Ω...
  • Page 132 ELEC ELECTRICAL COMPONENTS Main switch/seat lock Turn signal relay Rectifier/regulator Horn...
  • Page 133 ELEC IGNITION AND STARTER SYSTEM IGNITION AND STARTER SYSTEM CIRCUIT DIAGRAM . CDI magneto . Starter motor . CDI . “START” switch . Spark plug . Front brake switch . Main switch . Rear brake switch . Fuse . Ignition coil .

  • Page 134: Ignition And Starter System

    ELEC IGNITION AND STARTER SYSTEM SISTEMA DE ENCENDIDO Y ARRANQUE Spark plug Starter switch INDUCED COIL RESISTANCE: Ignition coil Main switch 0.05 ~ 0.06 _ at 20 °C (68 °F) CDI unit Front brake switch BRUSH WEAR LIMIT: Starter motor Rear brake switch 0.9 mm Starter relay...

  • Page 135: Troubleshooting

    ELEC IGNITION AND STARTER SYSTEM TROUBLESHOOTING IF THE IGNITION SYSTEM IS NOT OPERATING (NO SPARK OR INTERMITTENT SPARK) NOTE: • Remove the following parts before carrying out the repair of fault . 1) Side covers (right and left) 2) Rear cover 3) Footrest panel •...
  • Page 136 ELEC IGNITION AND STARTER SYSTEM 3. Spark plug cap resistance • Remove spark plug cap • Connect the pocket tester (Ωx1k) on the spark plug cap. • Check if the spark plug pipe has the spe- cified resistance Resistance of spark plug: 5 kΩ...
  • Page 137 ELEC IGNITION AND STARTER SYSTEM 5. Pick up coil resistance • Disconnect the Pick up coil coupler of the installation • Connect the pocket tester (Ωx100) on the pick up coil terminal. Cable (+) of tester White blue Cable (–) of tester Black •...
  • Page 138 ELEC IGNITION AND STARTER SYSTEM THE STARTER MOTOR DOES NOT FUNCTION NOTE: • Remove the following parts before repairing the faults. 1) Side covers (right and left) 2) Rear cover 3) Front mudguard 4) Handlebar cover (upper) • Use the following special tool for these repairs. Pocket tester: 90890-03112 1.
  • Page 139 ELEC IGNITION AND STARTER SYSTEM 4. Starter relay • Disconnect the starter relay cable from the installation. INCORRECT • Connect the battery to the starter relay cables as shown using the bridge cables • Check the operation of the starter motor. The main switch is defective, change.

  • Page 140: Charging System

    ELEC CHARGING SYSTEM CHARGING SYSTEM CIRCUIT DIAGRAM Flywheel Magneto Fuse Battery Rectifier/Regulator 7-10...
  • Page 141 ELEC CHARGING SYSTEM TROUBLESHOOTING THE BATTERY IS NOT CHARGED NOTE: • Remove the following parts before carrying out the repair of the fault. 1) Side covers (right and left) 2) Rear cover • Use the following special tool for this repair. Inductive tachometer: Pocket tester: 90890-03113...
  • Page 142 ELEC CHARGING SYSTEM 4. Charge coil resistance • Disconnect the charge coil coupler from the installation. • Connect the pocket tester(Ωx1) on the charge coils. • Measure the resistances of the charge coil. Cable (+) of the tester White cable Cable (–) of tester Yellow/Red Cable Charge coil resistance:...

  • Page 143: Lighting System

    ELEC LIGHTING SYSTEM LIGHTING SYSTEM CIRCUIT DIAGRAM Flywheel Light dinmer switch Headlamp Brake and rear light Meter light 7-13...
  • Page 144 ELEC LIGHTING SYSTEM TROUBLESHOOTING HEADLAMP, “HIGH BEAM” LIGHT INDICATOR, REAR LIGHT AND/OR METER LIGHT DO NOT LIGHT UP NOTE: • Remove the following parts before repairing the faults. 1) Side covers (right and left) 2) Rear cover 3) Handlebar cover (upper) •...

  • Page 145: Checking Of Lighting System

    ELEC LIGHTING SYSTEM 3. Connections Check the connections throughout the ligh- BAD CONNECTION ting system. See “ELECTRICAL DIAGRAM” section Correct CORRECT The circuit is in good condition CHECKING LIGHTING SYSTEM 1. The headlight does not light NO CONTINUITY 1. Bulb and bulb holder •...
  • Page 146 ELEC LIGHTING SYSTEM 2. The panel light does not light. NO CONTINUITY 1. Bulb and bulb holder • Check the bulb and bulb holder to see if there is continuity. Replace the bulb and/or bulb holder. CONTINUITY 2. Voltage • Connect the pocket tester (20 V AC) on the bulb holder coupler.

  • Page 147: Signalling System

    ELEC SIGNALLING SYSTEM SIGNALLING SYSTEM CIRCUIT DIAGRAM Speed sensor Rear indicator light (Right) Main switch Tail light Fuse Horn Battery Indicator relay Horn Front brake switch “HORN” switch Rear brake switch “TURN” switch Oil level switch Front indicator light (Left) Motor lights Front indicator light (Right) Fuel sensor...
  • Page 148 ELEC SIGNALLING SYSTEM TROUBLESHOOTING • INDICATOR LIGHT, BRAKE LIGHT, AND/OR INDICATING LIGHTS DO NOT LIGHT. • THE HORN DOES NOT SOUND NOTE: • Remove the following parts before repairing the faults . 1) Front cover . 4) Front lower fender 2) Inner cover 3) Rear panel (battery box) •...

  • Page 149: Checking Of Signalling System

    ELEC SIGNALLING SYSTEM 4. Connections • Check the connections throughout the sig- BAD CONNECTION nalling system. • See the “ELECTRICAL DIAGRAM”section Repair CORRECT Check the conditions for each signalling sys- tem circuit. Consult the “CHECKING SIGNALLING SYS- TEM” section. CHECKING SIGNALLING SYSTEM 1.
  • Page 150 ELEC SIGNALLING SYSTEM 3. Horn • Disconnect the “Pink” cable from the horn THE HORN SOUNDS terminal. • Connect a bridge cable on the horn ter- minal and earth the bridge cable. • Place the main switch on “ON”. The horn is in good condition. THE HORN DOES NOT SOUND.
  • Page 151 ELEC SIGNALLING SYSTEM INCORRECT The brake switch is defective, change. CORRECTO 3.Voltage • Connect the pocket tester (20 V DC) on the bulb holder connector. Cable (+) of tester Green/Yellow Cable (–) of tester Black • Place the main switch on “ON”. •...
  • Page 152 ELEC SIGNALLING SYSTEM INCORRECT The “TURN” is defective, change the hand- lebar switch (left). 3.Voltage • Connect the pocket tester (20 V DC) on the flasher relay . Cable (+) of tester Brown Cable (–) of tester Fame ground • Place the main switch on “ON”. •...
  • Page 153 ELEC SIGNALLING SYSTEM • Place the main switch on “f”. • Place the switch “b” on position “c” or “d”. • Check if there is a voltage (12 V) on the OUTSIDE SPECIFIED VALUE “Chocolate” or “Dark Green” cable of the bulb holder connector.
  • Page 154 ELEC SIGNALLING SYSTEM • Place main switch on “*” • Check if there is a voltage (12 V) on the OUTSIDE SPECIFIED VALUE “Gray” cable of the bulb holder connector SATISFIES THE SPECIFIED VALUE 4. Connections (12 V) • Check the connections throughout the sig- nalling system.
  • Page 155 ELEC SIGNALLING SYSTEM 2. Speed sensor • Connect the pocket tester (DC 20 V) to the speed sensor coupler (wire harness side) as shown. Positive tester probe blue/green Negative tester probe black/yellow L B R • Set the main switch to “ON”. •...
  • Page 156 AVER...
  • Page 157 AVER CHAPTER 8 LOCATION AND REPAIR OF BREAKDOWNS LOCATION AND REPAIR OF ENGINE BREAKDOWNS ……………………8-1 ELECTRICAL SYSTEM ………………………………………………………8-1 COMPRESSION SYSTEM ……………………………………………………8-2 INLET AND EXHAUST SYSTEM ……………………………………………8-3 ELECTRICAL DIAGRAM YN50...
  • Page 158 TROUBLE SHOOTING AVER ELECTRICAL SYSTEM IGNITION COIL * CHECK ALL CABLE CONNECTIONS • The primary and secondary coils are broken or defective. • The high voltage cable is defective. MAIN SWITCH • The spark plug cap is • The main switch is short defective.
  • Page 159 TROUBLE SHOOTING AVER COMPRESSION SYSTEM FATIGUE/CRACKS DEFECTIVE SEALING DAMAGE DAMAGE/WEAR DAMAGE/WEAR WEAR/CRACKS/DAMAGE DAMAGE WEAR/STRIPING INSUFFICIENT TIGHTENING TORQUE WEAR/CATCHING/BREAKS CARBON DEPOSITS DAMAGE WARPING/CARBON DEPOSITS...
  • Page 160 TROUBLE SHOOTING AVER INLET AND EXHAUST SYSTEM FUEL TANK CAP FUEL COCK • Obstructed • Obstructed DAMP TYPE FUEL PIPE • Obstructed AIR FILTER ELEMENT • Dirty or obstructed CARBURETTOR JOINT • Air leaks MUFFLER • Obstructed EXHAUST PIPE • Cracked or broken (CARBURETTOR) •...
  • Page 161 COMPONENTS ELECTRICAL DIAGRAM YN50 COLOUR CODE Flywheel magneto B .......BLACK R .......RED CDI UNIT SPEED SENSOR L........BLUE Spark plug G.......GREEN Main switch O.......ORANGE Fuse Y .......YELLOW P .......PINK Battery Rectifier/regulator BR......BROWN Starter relay CH ......CHOCOLATE Starter motor SB......SKY BLUE DG ......DARK GREEN Starter switch Horn switch W ......WHITE...

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2002 yb50

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