KTM 640 LC4 ADVENTURE Owner's Manual page 45

TROUBLE
Engine switches on but does
not start
Engine does not idle
44
Engine does not rev up
Engine does not
enough power
CAUSE
Spark plug connector or spark plug
is defective
Socket connector on CDI unit,
pulse generator or ignition coil
oxidizes
Water in the carburetor or jets
clogged
Carburetor not correctly connected
to intake flange
Idling jet is clogged
Adjusting screws on the carburetor
are turned in the wrong position
Spark plug is defective
Ignition system is defective
Fuel level is too high in the
carburetor
Float needle valve leaks
Float leaks
Choke cable has no clearance,
causing the cold-start system to be
constantly activated
Throttle slide diaphragm
defective
Leaks in the carburetor
Loose carburetor jets
Defective electronic
advance
have The fuel supply is partly interrupted
or the carburetor soiled
Float leaks
Diaphragm on the throttle slide is
defective
Carburetor leaks
Air filter is heavily soiled
Valve clearance is too small
Compression loss due to incorrect
adjustment of hand decompression
lever
Electronic ignition
defective
REMEDY
Remove the spark plug, connect the ignition wire, apply the
spark plug to the ground (bright area on the engine) and start;
a strong spark should be visible at the spark plug
– if no spark is visible, replace the spark plug
– if no spark is visible yet, disconnect the spark plug cap
from the ignition wire, hold approx. 5 mm away from the
ground and start
– if a spark is visible now, replace the spark plug connector
– if no spark is visible, have the ignition system checked
Remove the seat, right side cover and fuel tank, clean the
socket connectors and treat with contact spray
Remove and clean the carburetor
Mount the carburetor correctly
Disassemble the carburetor and clean the jets
Have the carburetor adjusted
Replace the spark plug
Have the ignition system checked
Disassemble the carburetor, clean and check for wear
Replace the float needle valve
Replace the float
Adjust the choke cable
is Replace the diaphragm
Check the vacuum hoses and vent hoses on the carburetor for
a tight fit and kink-free installation
Tighten the jets
ignition Have the ignition system checked
Clean and check the fuel system and the carburetor; have the
fuel pump checked
Replace the float
Replace the diaphragm
Check the vacuum hoses and vent hoses on the carburetor for
a tight fit and kink-free installation
Clean or replace the air filter, visit an authorized workshop
Have the valve clearance adjusted
Adjust the hand decompression cable
advance is Have the ignition system checked