TROUBLESHOOTING 91
Faults Possible cause Action
The engine cannot be cranked (elec-
tric starter)
(250 EXC AUS/XC‑W/XC,
all 300 models)
Operating error – Go through the steps of starting the engine.
( p. 31)
Battery discharged –
Recharge the battery. x ( p. 72)
–
Check the charging voltage. x
–
Check the closed current. x
–
Check the alternator. x
Fuse blown – Remove the fuse. ( p. 73)
– Replace the fuse. ( p. 73)
Starter relay faulty –
Check the starter relay. x
Starter motor faulty –
Check the starter motor. x
Engine turns but does not start Operating error – Go through the steps of starting the engine.
( p. 31)
Motorcycle was out of use for a long
time and there is old fuel in the float
chamber
–
Empty the carburetor float chamber. x
( p. 87)
Fuel feed interrupted – Check the fuel tank breather.
– Clean the fuel tap.
– Check/set the carburetor components.
Spark plug oily or wet – Clean and dry the spark plug, or change it if
necessary.
Electrode distance (plug gap) of spark
plug too wide
– Adjust the plug gap.
Guideline
(All 125/150/200 models)
Spark plug electrode gap
0.60 mm (0.0236 in)
(All 250/300 models)
Spark plug electrode gap
0.60 mm (0.0236 in)
Fault in ignition system –
Check the ignition system. x
Short circuit cable in wiring harness
frayed, short circuit button defective
–
Check the short circuit button. x
Socket connector or ignition coil is
loose or oxidized
– Clean the plug-in connector and treat it with
contact spray.
Water in carburetor or jets blocked – Check/set the carburetor components.
Engine has no idle Idling jet blocked – Check/set the carburetor components.
Adjusting screws on carburetor dis-
torted
–
Carburetor - adjust the idle speed. x
( p. 86)
Spark plug defective – Change the spark plug.
Ignition system defective –
Check the ignition coil. x
–
Check the spark plug connector. x
Engine does not speed up Carburetor running over because float
needle dirty or worn
– Check/set the carburetor components.
Loose carburetor jets – Check/set the carburetor components.
Fault in ignition system –
Check the ignition system. x
Engine has too little power Fuel feed interrupted – Check the fuel tank breather.
– Clean the fuel tap.
– Check/set the carburetor components.
Air filter very dirty –
Clean the air filter. x ( p. 82)
Exhaust system leaky, deformed or
too little glass fiber yarn filling in
main silencer
– Check exhaust system for damage.
– Change the glass fiber yarn filling of the main
silencer. x ( p. 81)
Fault in ignition system –
Check the ignition system. x
Diaphragm or reed valve housing
damaged
– Check the diaphragm and reed valve housing.