The following guide for troubleshooting does not
cover all the possible causes of trouble. It should
be helpful, however, as a guide to basic trouble-
shooting. Refer to the relative procedure in this
manual for checks, adjustments, and replace-
ment of parts.
EAS28470
STARTING FAILURES
Engine
1. Cylinder(s) and cylinder head(s)
●
Loose spark plug
● Loose cylinder head or cylinder
● Damaged cylinder head gasket
● Damaged cylinder gasket
● Worn or damaged cylinder
● Incorrect valve clearance
●
Improperly sealed valve
● Incorrect valve-to-valve-seat contact
● Incorrect valve timing
● Faulty valve spring
● Seized valve
2. Piston(s) and piston ring(s)
● Improperly installed piston ring
● Damaged, worn or fatigued piston ring
● Seized piston ring
● Seized or damaged piston
3. Air filter
● Improperly installed air filter
● Clogged air filter element
4. Crankcase and crankshaft
● Improperly assembled crankcase
● Seized crankshaft
Fuel system
1. Fuel tank
● Empty fuel tank
● Clogged fuel filter
● Clogged fuel strainer
● Clogged fuel tank drain hose
● Clogged rollover valve
● Clogged rollover valve hose
● Deteriorated or contaminated fuel
2. Fuel pump
● Faulty fuel pump
●
Faulty fuel pump relay
3. Fuel cock
● Clogged or damaged fuel hose
4. Carburetor(s)
● Deteriorated or contaminated fuel
●
Clogged pilot jet
● Clogged pilot air passage
● Sucked-in air
● Damaged float
● Worn needle valve
● Improperly installed needle valve seat
●
Incorrect fuel level
● Improperly installed pilot jet
● Clogged starter jet
● Faulty starter plunger
● Improperly adjusted starter cable
Electrical system
1. Battery
● Discharged battery
● Faulty battery
2. Fuse(s)
● Blown, damaged or incorrect fuse
●
Improperly installed fuse
3. Spark plug(s)
● Incorrect spark plug gap
● Incorrect spark plug heat range
● Fouled spark plug
●
Worn or damaged electrode
● Worn or damaged insulator
● Faulty spark plug cap
4. Ignition coil(s)
● Cracked or broken ignition coil body
● Broken or shorted primary or secondary coils
● Faulty spark plug lead
5. Ignition system
● Faulty ignitor unit
● Faulty pickup coil
● Broken generator rotor woodruff key
6. Switches 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
● Improperly grounded circuit
● Loose connections
7. Starting system
●
Faulty starter motor
● Faulty starter relay
● Faulty starting circuit cut-off relay
● Faulty starter clutch
EAS28490
INCORRECT ENGINE IDLING SPEED
Engine
1. Cylinder(s) and cylinder head(s)
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