Yamaha YFM660FS, Supplementary Service Manual

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TRBL
SHTG
STARTING FAILURE/HARD STARTING
TROUBLESHOOTING
NOTE:
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 inspection,
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
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
CDI system
●
Faulty CDI unit
●
Faulty pickup coil
●
Faulty charging/rotor rotation direction coil
●
Broken woodruff key
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
●
Clogged starter jet
●
Starter plunger malfunction
Air filter
●
Clogged air filter element
Switches and wiring
●
Faulty main switch
●
Faulty engine stop switch
●
Broken or shorted wiring
●
Faulty gear position switch
●
Faulty start switch
●
Faulty rear brake switch
Starter motor
●
Faulty starter motor
●
Faulty starter relay
●
Faulty starter clutch
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