Troubleshooting - KTM 450 EXC-R EU Repair Manual

TROUBLESHOOTING

Faults
The engine cannot be cranked (electric
starter).
Engine turns but does not start.
Possible cause
Operating error
Battery discharged
Fuse blown
Low external temperature
Operating error
Motorcycle was out of use for a long time
and there is old fuel in the float chamber
Fuel feed interrupted
Engine flooded
Spark plug oily or wet
Electrode distance (plug gap) of spark
plug too wide
Spark plug connector or spark plug defec-
tive
Short-circuit cable in cable harness
frayed, short-circuit button or emergency
OFF switch defective
Socket connector of CDI control device,
pulse generator or ignition coil oxidized.
Measure
Perform the steps necessary to start
the engine.
Recharge the battery. (
Check the cause of discharging.
Remove the fuse. ( P. 42)
Replace the fuse. ( P. 42)
Start the engine with the kickstarter.
Recharge the battery. Establish the
reason for discharging or have it
checked in a KTM workshop.
Perform the steps necessary to start
the engine.
Empty the carburetor float chamber.
( P. 127)
Check tank vent.
Clean fuel tap.
Clean carburetor.
Clean and dry spark plug or replace if
necessary.
Clean and dry spark plug or replace if
necessary.
Adjust plug gap.
Specification
Spark plug electrode gap
0.8... 0.9 mm (0.03... 0.04 in)
Warning
Risk of injury The ignition
system is under high voltage.
Do not touch parts of the ig-
nition system. Have work on
the ignition system carried
out in an authorized KTM
workshop.
Remove spark plug, connect ignition
cable, hold spark plug to ground (bare
metal area on engine), and try to start
the engine.
Specification
You should see a strong spark on the
spark plug.
If there is no spark, change the spark
plug.
If there is still no spark, remove the
spark plug cap from the ignition cable,
hold it at the specified distance from
the ground contact, and try to start the
engine.
Specification
5 mm (0.2 in)
If you now have a spark, replace the
spark plug connector.
If there is no spark, have the ignition
system checked.
Check wiring harness. (visual check)
Check electrical system.
Clean socket connector and treat it
with contact spray.
140
P. 43)