Kohler Command CH20 Service Manual page 25

IMPCO Carburetor
NOTE: Do not loosen or alter mounted position of
clamping brackets and/or stop collar on throttle
shaft. Each is preset, in correlation to a specifi c
position of throttle plate (shaft), or acts as a stop.
None of these attached components, including
throttle plate or shaft, requires disassembly or
removal for any carburetor servicing. All
components on throttle shaft should be left
intact. If settings of any one of these is
inadvertently loosened or altered, each must be
checked/reset, or performance and operation
will be aff ected. Refer to procedure included in
reassembly/installation sequence to check or
reset.
1. Turn off fuel supply at tank.
2. Remove air cleaner, breather hose, fuel line, vacuum
hose, choke, and throttle linkages. Remove
mounting hardware, carburetor, and gaskets from
engine. Discard gaskets.
3. Carburetor venturi may be removed for inspection
and appropriate cleaning.
a. Remove screws securing air cleaner adapter and
gasket to carburetor.
b. Mark a small line on outer edge of venturi for
proper orientation and reinstallation later.
c. Loosen venturi retaining screw on side of
carburetor body and lift out venturi.
4. Inspect overall condition of fuel enrichment hose
attached to carburetor. It must be free of cracks,
deterioration, and damage. Disconnect fuel
enrichment hose from carburetor fi ttings to clean or
check condition as required. Replace with a new
Kohler high pressure hose (LP rated) if condition is
questionable in any way. Secure new hose using
new clamps.
5. Clean all parts as required, use a good carburetor
cleaner, following manufacturer's instructions. Blow
clean, compressed air through all passages. Do not
poke or probe into load block assembly as damage
can be done, resulting in serious operational
problems.
Nikki Carburetor
1. Turn off fuel supply.
2. Remove air cleaner, breather hose, fuel line, vacuum
hose, choke, and throttle linkages. Remove nuts,
carburetor, and gaskets from engine. Discard
gaskets.
3. Remove fuel transfer chamber cover by removing
screws. Carefully remove cover and gasket. Discard
gasket.
4. Main jet is fi xed and nonadjustable, but may be
accessed for cleaning by removing rear plug and
sealing washer. Discard washer.
5. In order to clean off -idle transfer passages and
carburetor thoroughly, use a good carburetor cleaner
and follow manufacturer's instructions. Blow clean,
compressed air through passages and make sure all
are open before reassembling. Do not use wire or
metal objects to clean passages or carburetor body.
24 690 30 Rev. G
LPG/NG Carburetor - Inspection
NOTE: Do not attempt to disassemble or remove either
shaft from carburetor body, including mounted
clamp brackets on IMPCO style carburetors.
Screws attaching choke and throttle plate to
their respective shafts are staked or bonded to
prevent loosening. Plate(s) and shaft(s) are not
available separately. If detrimental wear or
damage is found in any parts, carburetor should
be replaced.
1. Inspect carburetor body and removable venturi
(IMPCO carburetor) for cracks, holes, and other
wear or damage.
2. Check choke shaft (Nikki carburetor only) and
throttle shaft for wear and free movement.
LPG/NG Carburetor - Reassembly
IMPCO Carburetor
NOTE: Clamp brackets and stop collar mounted on
throttle shaft should still be in their original
positions, and not require any readjustment/
resetting. If mounted position of any one of these
was aff ected or changed, it will be necessary to
check and reset position of each before
proceeding. Follow Instructions for Checking/
Positioning Clamp Brackets Mounted on Throttle
Shaft, then continue with steps 6 and 7.
1. Slide venturi into carburetor body, aligning position
mark made prior to removal. Correctly installed,
discharge holes should not be visible from top.
2. Secure with venturi retaining screw. Torque screw to
4.0 N·m (36 in. lb.).
3. Install a new adapter gasket and mount air cleaner
adapter onto carburetor with screws. Torque screws
to 4.0 N·m (36 in. lb.).
4. Install a new carburetor gasket onto intake manifold
adapter, followed by carburetor. Install and fi nger
tighten mounting fasteners.
5. Connect Z end of throttle linkage and dampening
spring to throttle clamp bracket on throttle shaft.
Attach opposite end of linkage and spring to
governor lever.
6. Manually move governor lever toward carburetor as
far as it will go.
7. Check that throttle plate is now fully open or
reposition carburetor slightly on mounting hardware
so it is fully open. Torque mounting screws or nuts to
6.2-7.3 N·m (55-65 in. lb.).
Nikki Carburetor
NOTE: If additional adjustment is required, loosen
throttle linkage clamp bracket mounting screw,
set throttle shaft to full throttle position against
head of stop screw, and retighten clamp
mounting screw securely.
1. Reinstall rear plug with a new sealing washer.
Tighten plug securely.
2. Reinstall fuel transfer chamber cover with a new
gasket. Secure with screws.
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Fuel System
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