KTM 250 SX-F 2005, Repair Manual

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9-2
Repair manual KTM 250 SX-F
Art.-No. 3.206.027-E
ERROR
Engine does not switch on
Engine runs poorly/does not
run in idle
CAUSE
Motorcycle has not been used for a
longer period of time, leaving old
fuel in the float chamber
Fuel supply is interrupted
Engine is flooded
Spark plug is sooted or wet
Electrode distance is too large
Spark plug connector or spark plug
is defective
Short circuit cable in the wiring
harness is scuffed, emergency OFF
switch or the short circuit button
is defective
Plug connector from the CDI unit,
pulse generator or ignition coil has
oxidized
Water in the carburetor or jets
clogged
Idling jet clogged
Adjusting screws on the carburetor
are distorted
Spark plug is defective
Ignition system is defective
REMEDY
Open the fuel tap, refuel, do not actuate the choke, follow
start-up instructions (see driving instructions)
The highly inflammable constituents in the new fuel volatize
if left standing over longer periods of time.
If the motorcycle was not used for over 1 week, drain the old
fuel from the float chamber. The engine will start
immediately after the float chamber is filled with fresh
ignitable fuel.
Disconnect the fuel hose from the carburetor, place the end
in a vessel and open the fuel tap,
– if fuel leaks out, clean the carburetor
– if no fuel leaks out, check the tank ventilation and clean
the fuel tap
Open the throttle completely, actuate the kickstarter 5 - 10
times. Then start the engine as described above. If the
engine still won't start, unscrew the spark plug and dry.
Clean and dry or replace the spark plug
Set the electrode distance to 0.6 mm
Remove the spark plug, connect the ignition wire, hold the
spark plug against the ground (bright side facing the engine)
and start. A strong spark should be visible at the spark plug.
– if there is no spark, replace the spark plug
– if there is still no spark, disconnect the spark plug
connector from the ignition wire, hold approx. 5 mm away
from the ground and start
– if there is a spark, replace the spark plug connector
– if there is still no spark, have the ignition system checked
with the peak voltage adapter
Remove the fuel tank, disconnect the black/yellow cable
from the emergency OFF switch or short-circuit button and
check the spark.
If there is a spark, look for the error in the short circuit
Remove the seat and fuel tank, clean the socket connector
and treat with contact spray
Dismount and clean the carburetor
Disassemble the carburetor and clean the jets
Adjust the carburetor
Replace the spark plug
Check the ignition system