Poor Medium-And-High-Speed Performance; Faulty Gear Shifting; Shift Pedal Does Not Move; Jumps Out Of Gear - Yamaha Vmax VMX17C 2009 Service Manual

Electrical system
1. Battery
• Discharged battery
• Faulty battery
2. Spark plug(s)
• Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
3. Ignition coil(s)
• Broken or shorted primary or secondary coils
• Cracked or broken ignition coil
4. Ignition system
• Faulty ECU
• Faulty crankshaft position sensor
• Faulty cylinder identification sensor
• Broken generator rotor woodruff key
EAS28520
POOR MEDIUM-AND-HIGH-SPEED
PERFORMANCE
Refer to "STARTING FAILURES" on page 9-1.
Engine
1. Air filter
• Clogged air filter element
Fuel system
1. Fuel pump
• Faulty fuel pump
EAS28530

FAULTY GEAR SHIFTING

Shifting is difficult
Refer to "Clutch drags".
EAS28540

SHIFT PEDAL DOES NOT MOVE

Shift shaft
• Improperly adjusted shift rod
• Bent shift shaft
Shift drum and shift forks
• Foreign object in a shift drum groove
• Seized shift fork
• Bent shift fork guide bar
Transmission
• Seized transmission gear
• Foreign object between transmission gears
• Improperly assembled transmission
TROUBLESHOOTING
EAS28550

JUMPS OUT OF GEAR

Shift shaft
• Incorrect shift pedal position
• Improperly returned stopper lever
Shift forks
• Worn shift fork
Shift drum
• Incorrect axial play
• Worn shift drum groove
Transmission
• Worn gear dog
EAS28570

FAULTY CLUTCH

Clutch slips
1. Clutch
• Improperly assembled clutch
• Improperly assembled clutch master cylinder
• Improperly assembled clutch release cylinder
• Incorrect clutch fluid level
• Damaged clutch hose
• Loose or fatigued clutch spring
• Loose union bolt
• Worn friction plate
• Worn clutch plate
• Damaged clutch release cylinder
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity (low)
• Deteriorated oil
Clutch drags
1. Clutch
• Air in hydraulic clutch system
• Unevenly tensioned clutch springs
• Warped pressure plate
• Bent clutch plate
• Swollen friction plate
• Bent clutch push rod
• Damaged clutch boss
• Burnt primary driven gear bushing
• Damaged clutch release cylinder
• Match marks not aligned
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity (high)
• Deteriorated oil
9-2