Carburetor - Adjusting Idle - KTM 400 EXC EU Owner's Manual

MAINTENANCE WORK ON CHASSIS AND ENGINE

Carburetor - adjusting idle

9.107
x
–
Screw in the idle adjusting screw
setting.
Guideline
Idle mixture adjusting screw (400 EXC)
Open
Idle mixture adjusting screw (530 EXC, 530 EXC SIX DAYS, 450 XC-W ZA,
530 XC-W ZA)
Open
400341-10
Idle mixture adjusting screw (450 EXC, 450 EXC SIX DAYS, 400 XC-W USA,
450 XC-W USA)
Open
Idle mixture adjusting screw (530 XC-W USA)
Open
Adjustment tool for mixture control screw (77329034000)
–
Run the engine until warm.
Guideline
Warm-up time
Danger
Danger of poisoning Exhaust gases are poisonous and can result in uncon-
sciousness and/or death.
–
–
Adjust the idle speed with adjusting screw
Guideline
Choke function deactivated – The choke lever is pushed in to the stop.
(EXC AUS, XC‑W) (
Choke function deactivated – The choke lever is pushed back to the stop.
(EXC EU, EXC SIX DAYS) (
Idle speed
–
Turn the idle adjusting screw
–
Note the position and turn the idle adjusting screw slowly counterclockwise until
the idle speed falls.
–
Adjust to the point between these two positions with the highest idle speed.
Info
If there is a big engine speed rise, reduce the idle speed to a normal level
and repeat the above steps.
The extreme sport motorcyclist will set the mixture about ¼ of a turn back
from this ideal value (leaner, in a clockwise direction) since the engine
becomes hotter in sporting use.
If the procedure described here does not lead to satisfactory results, the
cause may be a wrongly dimensioned idling jet.
If you can turn the idle adjusting screw to the end without any change of
engine speed, you have to mount a smaller idling jet.
The idle adjusting screw must not be opened more than two turns. If more
than two turns are necessary (rich mixture), use a larger idling jet.
After changing the idling jet, start from the beginning with the adjusting
steps.
until it stops and then to the prescribed basic

When running the engine, always make sure there is sufficient ventila-
tion, and do not start or run the engine in a closed space.
p. 20)
p. 21)
slowly until the idle speed begins to fall.

0.75 turn
1.5 turns
1.75 turns
2.0 turns
≥ 5 min
.

1,550... 1,650 rpm
78