20 Troubleshooting - KTM 450 SX-F FACTORY EDITION Owner's Manual

20 TROUBLESHOOTING

Faults
The engine does not turn when
the start button is pressed
Engine turns but does not start
Engine does not speed up
Engine has too little power
Engine dies during the trip
Engine overheats
126
Possible cause
Operating error
12 V battery discharged
Main fuse blown
Starter relay defective
Starter motor defective
Quick release coupling not
joined
Fuel screen in the quick release
coupling is clogged
Idle speed is not set correctly
Spark plug sooty or wet
Plug gap of spark plug too wide
Short-circuit cable in wiring
harness frayed, stop button
faulty
Malfunction in the electronic
fuel injection
Malfunction in the electronic
fuel injection
Air filter is very dirty
Fuel filter is very dirty
Malfunction in the electronic
fuel injection
Exhaust system leaky,
deformed or too little glass
fiber yarn filling in main
silencer
Valve clearance too little
Lack of fuel
Too little coolant in cooling sys-
tem
Too little air stream
Radiator fins very dirty
Foam formation in cooling sys-
tem
Bent radiator hose
Action
–
Carry out start procedure. (
–
Charge the 12-V battery.
–
Check the charging voltage.
–
Check the open-circuit current.
–
Check the stator winding of the alter-
nator.
–
Change the main fuse. (
–
Check the starter relay.
–
Check the starter motor.
–
Join quick release coupling.
–
Change the fuel screen.
–
Adjust the idle speed.
–
Clean and dry the spark plug and spark
plug connector, or change if necessary.
–
Adjust plug gap.
Guideline
Spark plug electrode gap
1.0 mm (0.039 in)
–
Check the wiring harness. (visual
check)
–
Check the electrical system.
–
Read out the fault memory using the
KTM diagnostics tool.
–
Read out the fault memory using the
KTM diagnostics tool.
–
Clean the air filter and air filter box.
( p. 65)
–
Change the fuel filter.
–
Read out the fault memory using the
KTM diagnostics tool.
–
Check exhaust system for damage.
–
Change the glass fiber yarn filling of
the main silencer. (
–
Adjust the valve clearance.
–
Refuel. ( p. 32)
–
Check the cooling system for leakage.
–
Check the coolant level. (
–
Switch off the engine when standing.
–
Clean radiator fins.
–
Drain the coolant. ( p. 106)
–
Refill with coolant. (
–
Change the radiator hose.
p. 25)
( p. 101)
p. 102)
( p. 116)
( p. 113)
p. 67)
p. 106)
p. 107)