Yamaha YFM90RA Model Vehicle User Manual


 
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TRBL
SHTG
EBS00537
TROUBLESHOOTING
TIP
The following troubleshooting does not cover all the possible causes of trouble. It should be helpful,
however, as a guide to troubleshooting. Refer to the relative procedure in this manual for check,
adjustment and replacement of parts.
STARTING FAILURE/HARD STARTING
FUEL SYSTEM
Fuel tank
Empty
Clogged fuel filter
Clogged fuel strainer
Clogged fuel breather hose
Deteriorated or contaminated fuel
Fuel cock
Clogged fuel hose
Carburetor
Deteriorated or contaminated fuel
Clogged pilot jet
Clogged pilot air passage
Sucked-in air
Deformed float
Worn needle valve
Improperly sealed valve seat
Improperly adjusted fuel level
Improperly set pilot jet
Air filter
Clogged air filter element
ELECTRICAL SYSTEM
Spark plug
Improper plug gap
Worn electrodes
Wire between terminals broken
Improper heat range
Faulty spark plug cap
Ignition coil
Broken or shorted primary/secondary
Faulty spark plug lead
Broken body
C.D.I. system
Faulty C.D.I. unit
Faulty pickup coil
Faulty source coil
Broken woodruff key
Switches and wiring
Faulty main switch
Faulty engine stop switch
Broken or shorted wiring
Faulty start switch
Starter motor
Faulty starter motor
Faulty starter relay
Battery
Faulty battery
STARTING FAILURE/HARD STARTING