Kohler COMMAND CH18, Service Manual

Page: 49 / 232

5.16
Section 5
Fuel System and Governor
4. Remove the screw securing the flat washer and
ground lead (if equipped), from the top of the
carburetor; then carefully pull (lift) out the two
slow jets. The slow jets may be sized/side
specific, mark or tag for proper reassembly. Note
the small O-Ring on the bottom of each jet. See
Figures 5-25 and 5-26. Save parts for cleaning
and reuse unless a Jet Kit is also being installed.
Clean the slow jets using compressed air. Do not
use wire or carburetor cleaner.
6. Clean the carburetor body, main jets, vent ports,
seats, etc. using a good commercially available
carburetor solvent. Keep away from plastic or
rubber parts if non-compatible. Use clean, dry
compressed air to blow out the internal channels
and ports. Do not use metal tools or wire to clean
orifices and jets. Inspect and thoroughly check
the carburetor for cracks, wear, or damage.
Inspect the fuel inlet seat for wear or damage.
Check the spring loaded choke plate to make sure
it moves freely on the shaft.
7. Clean the carburetor fuel bowl as required.
8. Install the two main nozzles into the towers of
the carburetor body. The end of the main nozzles
with the two raised shoulders should be out/
down (adjacent to the main jets). Make sure the
nozzles are completely bottomed. Carefully
install the main jets into the towers of the
carburetor body on the appropriate side, as
identified when removal was performed. See
Figure 5-27.
Figure 5-25. Removing Screw and Washer.
Figure 5-26. Slow Jets and O-Ring Detail.
5. Remove the idle speed (RPM) adjustment screw
and spring from the carburetor. Discard the parts.
NOTE: The carburetor is now disassembled for
appropriate cleaning and installation of the
parts in the overhaul kit. Further disassembly
is not necessary. The throttle shaft assembly,
fuel inlet seat, idle fuel adjustment screws
with limiter, and carburetor body, are non-
serviceable items and should not be removed.
The choke shaft assembly is serviceable,
however it should not be removed unless a
Choke Repair Kit will be installed.
Slow (Idle Fuel) Jets
O-Ring
Figure 5-27. Installing Main Nozzles and Main Jets.
9. Make sure the O-Ring near the bottom of each
slow jet is new, or in good condition. Align and
insert the two slow jets into the top of
carburetor. See Figure 5-26.
10. Install the large flat retaining washer and secure
with the mounting screw, attaching the ground
lead if originally secured by the screw.
11. Install the new idle speed (RPM) adjustment
screw and spring onto the carburetor. Thread in
until 3 or 4 threads are exposed, as an initial
adjustment. See Figure 5-28.
Nozzle End with
Two Shoulders
(Out/Down)
Main Jets