Chapter 8. Troubleshooting; Starting Failure/Hard Starting; Fuel System; Electrical System - Yamaha BT1100 2002 Service Manual

EB900000
NOTE:
The following guide for troubleshooting does not cover all the possible causes of problems. It should be
helpful, however, as a guide to troubleshooting. Refer to the relative procedure in this manual for inspec-
tion, adjustment and replacement of parts.

STARTING FAILURE/HARD STARTING

FUEL SYSTEM

Fuel tank
• Empty
• Clogged fuel filter
• Clogged fuel strainer
• Clogged fuel tank drain hose
• Clogged roll-over valve
• Clogged roll-over valve breather hose
• Deteriorated or contaminated fuel
Fuel cock
• Clogged fuel hose

ELECTRICAL SYSTEM

Spark plug
• Improper plug gap
• Worn electrodes
• Wire between terminals severed
• Improper heat range
• Faulty spark plug cap
Ignition coil
• Broken or shorted primary/secondary
• Faulty spark plug lead
• Broken body
Full-transistor system
• Faulty ignitor unit
• Faulty pickup coil
STARTING FAILURE/HARD STARTING
TROUBLESHOOTING
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
• Faulty starter plunger
• Improperly adjusted starter cable
Air filter
• Clogged air filter element
Fuel pump
• Faulty fuel pump
• Faulty relay unit (fuel pump relay)
Switch and wiring
• Faulty main switch
• Faulty engine stop switch
• Broken or shorted wiring
• Faulty neutral switch
• Faulty start switch
• Faulty sidestand switch
• Faulty clutch switch
Starter motor
• Faulty starter motor
• Faulty starter relay
• Faulty relay unit (starting circuit cut-off relay)
• Faulty starter clutch
8-1
TRBL
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SHTG