Yamaha 2004 YP400 Service Manual page 406

STARTING FAILURE/HARD STARTING .......................................................9-1
ENGINE..................................................................................................... 9-1
FUEL SYSTEM.......................................................................................... 9-1
ELECTRICAL SYSTEMS ..........................................................................9-2
INCORRECT ENGINE IDLING SPEED........................................................... 9-2
ENGINE..................................................................................................... 9-2
FUEL SYSTEM.......................................................................................... 9-2
ELECTRICAL SYSTEMS ..........................................................................9-2
POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE .................................9-3
ENGINE..................................................................................................... 9-3
FUEL SYSTEM.......................................................................................... 9-3
FAULTY CLUTCH ........................................................................................... 9-3
ENGINE OPERATES BUT SCOOTER WILL NOT MOVE........................9-3
CLUTCH SLIPS......................................................................................... 9-3
POOR STARTING PERFORMANCE........................................................9-3
POOR SPEED PERFORMANCE.............................................................. 9-3
OVERHEATING............................................................................................... 9-4
ENGINE..................................................................................................... 9-4
COOLING SYSTEM .................................................................................. 9-4
FUEL SYSTEM.......................................................................................... 9-4
CHASSIS...................................................................................................9-4
ELECTRICAL SYSTEMS ..........................................................................9-4
OVERCOOLING .............................................................................................. 9-4
COOLING SYSTEM .................................................................................. 9-4
POOR BRAKING PERFORMANCE................................................................9-5
FAULTY FRONT FORK LEGS........................................................................ 9-5
LEAKING OIL ............................................................................................ 9-5
MALFUNCTION......................................................................................... 9-5
UNSTABLE HANDLING.................................................................................. 9-5
CHAPTER 9
TROUBLESHOOTING
TRBL
SHTG