Faulty Gear Shifting; Hard Shifting; Shift Pedal Does Not Move; Jump-Out Gear - Yamaha YFM660RN Service Manual

FAULTY GEAR SHIFTING

HARD SHIFTING

Refer to "CLUTCH DRAGGING".

SHIFT PEDAL DOES NOT MOVE

Shift shaft
Bent shift shaft
Shift drum and shift fork
Groove jammed with impurities
Seized shift fork
Bent shift fork guide bar

JUMP-OUT GEAR

Shift shaft
Improperly adjusted shift lever position
Improperly returned stopper lever
Shift fork
Worn shift fork

CLUTCH SLIPPING/DRAGGING

CLUTCH SLIPPING

Clutch
Loose clutch spring
Fatigued clutch spring
Worn friction plate
Worn clutch plate
Incorrectly assembled clutch

CLUTCH DRAGGING

Clutch
Warped pressure plate
Unevenly tensioned clutch springs
Match marks not aligned
Loose clutch boss nut
Burnt primary driven gear bushing
Bent clutch plate
Swollen friction plate
Broken clutch boss
FAULTY GEAR SHIFTING/
CLUTCH SLIPPING/DRAGGING
Transmission
Seized transmission gear
Jammed impurities
Incorrectly assembled transmission
Shift guide
Broken shift guide
Shift drum
Improper thrust play
Worn shift drum groove
Transmission
Worn gear dog
Engine oil
Low oil level
Improper quality (low viscosity)
Deterioration
Transmission oil
High oil level
Improper quality (high viscosity)
Deterioration
9 - 3
TRBL
SHTG