Yamaha MZ250, Service Manual, Page: 9 / 118

INSTALLING THE FLYWEIGHT
SHAFT ASSEMBLY AND
GOVERNOR SHAFT ..........................3-19
ENGINE SWITCH AND OIL WARNING
UNIT .........................................................3-20
CYLINDER HEAD COVER, CYLINDER
HEAD .......................................................3-21
CHECKING THE ROCKER ARM .......3-23
CHECKING THE PUSH ROD .............3-23
CHECKING THE CYLINDER
HEAD ..................................................3-23
INSTALLING THE CYLINDER
HEAD ASSEMBLY ..............................3-24
VALVE ......................................................3-25
REMOVING THE VALVE AND
VALVE SPRING ..................................3-26
CHECKING THE VALVE AND
VALVE SPRING ..................................3-26
CHECKING THE VALVE SEAT ...........3-28
VALVE LAPPING ................................3-30
INSTALLING THE VALVE AND
VALVE SPRING ..................................3-31
PISTON, CAMSHAFT, CRANKCASE,
AND CRANKSHAFT ................................3-32
REMOVING THE CAMSHAFT AND
VALVE LIFTER ....................................3-34
CHECKING THE CAMSHAFT ............3-34
CHECKING THE VALVE LIFTER ........3-36
INSTALLING THE VALVE LIFTER
AND CAMSHAFT ...............................3-36
CHECKING THE CRANKCASE
COVER ...............................................3-36
INSTALLING THE CRANKCASE
COVER ...............................................3-37
CHECKING THE CYLINDER ..............3-37
CHECKING THE CRANKCASE .........3-38
CHECKING THE PISTON AND
PISTON PIN ........................................3-39
CHECKING THE PISTON RING ........3-41
CHECKING THE CRANKSHAFT .......3-42
CHECKING THE CONNECTING
ROD OIL CLEARANCE ......................3-44
INSTALLING THE PISTON AND
PISTON RING .....................................3-45
INSTALLING THE CRANKSHAFT ......3-46
SELECTING THE CRANKSHAFT
SHIM (P.T.O. SHAFT TYPE E) ............3-48
CHAPTER 4.
CARBURETOR
REMOVING THE CARBURETOR ..............4-1
DISASSEMBLING THE CARBURETOR ...4-2
MANUAL CHOKE MODEL ...................4-2
AUTO CHOKE MODEL.........................4-3
CHECKING THE CARBURETOR .........4-5
CHECKING THE CHOKE SOLENOID
(AUTO CHOKE MODEL) ......................4-6
CHAPTER 5.
ELECTRICAL
ELECTRICAL COMPONENTS ..................5-1
FUSE (ELECTRIC STARTING MODEL) ...5-2
CHECKING THE FUSE ........................5-2
SWITCHES .................................................5-4
CHECKING THE SWITCH
CONTINUITY .......................................5-4
IGNITION SYSTEM ....................................5-5
TROUBLESHOOTING CHART .............5-5
ELECTRIC STARTING SYSTEM
(ELECTRIC STARTING MODEL) ............5-11
TROUBLESHOOTING CHART ...........5-11
REMOVING THE STARTER
MOTOR ...............................................5-13
DISASSEMBLING THE STARTER
MOTOR ...............................................5-14
CHECKING THE ARMATURE
COIL ....................................................5-15
CHECKING THE BRUSH ...................5-16
CHECKING THE MAGNETIC
SWITCH ..............................................5-16
CHARGING SYSTEM
(WITH CHARGING COIL MODEL) .........5-18
TROUBLESHOOTING CHART ...........5-18