Yamaha 2002 YB50, Service Manual

Page: 51 / 161

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
SECONDARY PULLEY WHEEL ………………………………………………4-6
STARTER SYSTEM ……………………………………………………………4-7
TRANSMISSION ………………………………………………………………4-8
MAGNETIC FLYWHEEL ………………………………………………………4-8
AUTOLUBRICATION PUMP …………………………………………………4-9
CRANKCASE AND CRANKSHAFT …………………………………………4-9
INSPECTION AND REPAIR ……………………………………………………4-11
CYLINDER HEAD ……………………………………………………………4-11
CYLINDER AND PISTON ……………………………………………………4-11
PISTON RINGS ………………………………………………………………4-13
PISTON PIN AND PISTON PIN BEARING
………………………………4-14
KICK STARTER ………………………………………………………………4-15
TRANSMISSION………………………………………………………………4-16
AUTOLUBRICATION PUMP…………………………………………………4-16
CRANKSHAFT ………………………………………………………………4-16
PRIMARY PULLEY WHEEL …………………………………………………4-17
SECONDARY PULLEY WHEEL ……………………………………………4-18
TRAPEZOIDAL BELT …………………………………………………………4-19
GEARS AND STARTER CLUTCH …………………………………………4-19
ASSEMBLY AND ADJUSTMENT OF ENGINE ……………………………4-21
CRANKSHAFT AND CRANKCASE…………………………………………4-21
AUTOLUBRICATION PUMP…………………………………………………4-23
FLYWHEEL MAGNET ………………………………………………………4-24
TRANSMISSION………………………………………………………………4-25
STARTER MOTOR ……………………………………………………………4-27
SECONDARY PULLEY WHEEL ……………………………………………4-29
PRIMARY PULLEY WHEEL …………………………………………………4-29
STARTER PEDAL ……………………………………………………………4-30
PISTON AND PISTON PIN …………………………………………………4-35
CYLINDER AND HEAD ……………………………………………………4-36
ENGINE ASSEMBLY …………………………………………………………4-38
ENG