Adjusting The Mixture Control Screw - KTM 400-660 LC4 1998-2005 Repair Manual

8-38E

Adjusting the mixture control screw

The mixture control screw is difficult to reach. For this reasons, we have
created an appropriate special tool 590.29.034.000.
Introduce the special tool into the bore at the carburetor bottom. Press
1
the tool slightly upward and turn the adjusting wheel until the tool
engages the slot of the mixture control screw 2 .
Now, you can go about adjusting the screw. Marks were provided on
the adjusting wheel, making it easier to keep track of the turns.
1
2
Checking the float level (float height)
For this purpose, dismount the carburetor and remove the float
chamber. Hold the carburetor in a slanted position such that the float
will abut the float needle valve but not compress it (see photo).
Now, use a sliding caliper to measure the distance H between the
casing edge and the float's upper edge.
H
The float height is to be 9 mm.
If the float height does not correspond to the desired value, check the
float needle valve and, if necessary, replace it.
H
If the float needle valve is correct, you can adjust the float height by
3
bending of the float lever .
Mount the float chamber, install the carburetor, and adjust the idle
speed.
3