Troubleshooting - KTM 450 SX-F EU Owner's Manual

TROUBLESHOOTING

Faults
The engine cannot be cranked (elec-
tric starter)
Engine turns but does not start
Engine has no idle
Engine does not speed up
Engine has a lack of power
Engine stalls or pops back into the
carburetor
Possible cause
Operating error
Battery discharged
Main fuse blown
Low external temperature
Starter relay defective
Starter motor defective
Operating error
Motorcycle was out of use for a long
time and there is old fuel in the float
chamber
Fuel feed interrupted
Spark plug oily or wet
Electrode distance (plug gap) of spark
plug too wide
Ignition system defective
Short-circuit cable in wiring harness
frayed, short-circuit button defective
Plug connector of CDI control device,
pulse generator or ignition coil oxi-
dized.
Water in carburetor or jets blocked
Idling jet blocked
Adjusting screws on carburetor dis-
torted
Spark plug defective
Ignition system defective
Carburetor running over because float
needle dirty or worn.
Loose carburetor jets
Ignition system defective
Fuel feed interrupted
Air filter heavily contaminated
Exhaust system leaky, deformed or
too little glass fiber yarn filling in
main silencer
Valve clearance too little
Ignition system defective
Lack of fuel
Action
–
Carry out the start procedure. (
–
Recharge the battery.
x
–
Check the charging voltage.
–
Check the closed current.
–
Check the stator winding of the alternator.
–
Remove the main fuse. (
–
Install the main fuse. (
–
Use the battery supplied in the accessory pack-
age.
Battery (YTX5L-BS) ( p. 82)
–
Check the starter relay. x
–
Check the starter motor.
x
–
Carry out the start procedure. (
–
Empty the carburetor float chamber.
( p. 68)
–
Check the fuel tank breather.
–
Clean the fuel tap.
–
Check/adjust the carburetor components.
–
Clean and dry the spark plug or replace if nec-
essary.
–
Adjust the plug gap.
Guideline
Spark plug electrode gap
0.7 mm (0.028 in)
–
Check the ignition system.
–
Check the wiring harness. (visual check)
–
Check the electrical system.
–
Clean the plug connector and treat it with con-
tact spray.
–
Check/adjust the carburetor components.
–
Check/adjust the carburetor components.
–
Carburetor - adjust the idle speed.
( p. 68)
–
Change spark plug.
–
Check the ignition system.
–
Check/adjust the carburetor components.
–
Check/adjust the carburetor components.
–
Check the ignition system.
–
Check the fuel tank breather.
–
Clean the fuel tap.
–
Check/adjust the carburetor components.
–
Clean the air filter and air filter box.
( p. 39)
–
Check exhaust system for damage.
–
Change the glass fiber yarn filling of the main
silencer. ( p. 40)
x
–
Set the valve clearance. x
–
Check the ignition system.
–
Turn handle of the fuel tap to the ON posi-

tion. (Figure 800189-10
–
Refuel. ( p. 20)
76
p. 18)
( p. 61)
x
x
x
p. 62)
p. 63)
p. 18)
x
x
x
x
x
x
x
x
x
x
x
x
x
p. 12)