Yamaha PW50W 2007 Service Manual page 163

POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE/
EAS28510
POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE
Refer to "STARTING FAILURES".
ENGINE
Autolube pump
9 Faulty autolube pump
Air filter
9 Clogged air filter element
Exhaust system
9 Carbon buildup
EAS28580
FAULTY CLUTCH
ENGINE OPERATES BUT VEHICLE WILL
NOT MOVE
Clutch spring(s)
9 Damaged clutch spring
Transmission gear(s)
9 Damaged transmission gear
Shaft drive
9 Broken shaft drive
CLUTCH SLIPS
Clutch shoe spring(s)
9 Damaged, loose or worn clutch shoe
spring
Clutch shoe(s)
9 Damaged or worn clutch shoe
EAS28590
OVERHEATING
ENGINE
Cylinder head(s) and piston(s)
9 Heavy carbon buildup
Autolube pump
9 Faulty autolube pump
9 Incorrect engine oil grade
FUEL SYSTEM
Carburetor(s)
9 Incorrect main jet setting
9 Incorrect fuel level
9 Damaged or loose carburetor joint
Air filter
9 Clogged air filter element
FAULTY CLUTCH/OVERHEATING
FUEL SYSTEM
Carburetor(s)
9 Incorrect fuel level
9 Loose or clogged main jet
POOR STARTING PERFORMANCE
Clutch shoe(s)
9 Bent, damaged or worn clutch shoe
9 Poor speed performance
CHASSIS
Brake(s)
9 Dragging brake
ELECTRICAL SYSTEM
Spark plug(s)
9 Incorrect spark plug gap
9 Incorrect spark plug heat range
Ignition system
9 Faulty CDI unit
8-3
TRBL
SHTG