Kohler Command CH620 - Manual (Page 14)

14
Carburetor Troubleshooting and
Adjustments
Engines in this series use either a one- or two-barrel
carburetor depending on model, and may also be
equipped with a Governed Idle System. Specific
adjustment procedures are provided based on the
model and carburetor involved. If the engine is
equipped with a Governed Idle System, refer to Models
with Governed Idle System on page 15 when
performing any carburetor adjustment, as an
additional step to the listed adjustment procedure(s) is
required.
NOTE: Carburetor adjustments should be made only
after the engine has warmed up.
The carburetor is designed to deliver the correct
fuel-to-air mixture to the engine under all operating
conditions. To comply with current emission
regulations, the fuel mixture settings are made at the
factory and cannot be adjusted.
NOTE: To ensure correct engine operation at altitudes
above 1525 meters (5000 ft.), it may be
necessary to have an authorized Kohler dealer
install a special high-altitude jet kit in the
carburetor. If a high-altitude kit has been
installed, the engine must be reconverted to
the original jet size, before it is operated at
lower altitudes, or overheating and engine
damage can result.
Figure 15. EFI Fuel Filter and Line.
Replacement is recommended every 1500 hours, or
more frequently under extremely dusty or dirty
conditions. When replacement is necessary, always
use genuine Kohler parts.
Fuel Line
Carbureted Engines: In compliance with CARB Tier
III Emission Regulations, carbureted engines with a
Family identification number beginning with “6” or
greater (see Figure 16), must use Low Permeation SAE
30 R7 rated fuel line; certified to meet CARB
requirements. Standard fuel line may not be used.
Order replacement hose by part number through a
Kohler Engine Service Dealer.
EFI Engines: A special, high volume, high pressure
filter with greater filtration capabilities and internal
surface area is used. See Figure 15.
Fuel Filter
Fuel Line
KOHLER CO. KOHLER, WISCONSIN USA
EMISSION COMPLIANCE PERIOD:
EPA:
CARB:
CERTIFIED ON:
REFER TO OWNER'S MANUAL FOR HP RATING,
SAFETY, MAINTENANCE AND ADJUSTMENTS
1-800-544-2444 www.kohlerengines.com
FAMILY 6 KHXS.XXXX PH
TYPE APP
DISPL. (CC)
MODEL NO.
SPEC. NO.
SERIAL NO.
BUILD DATE
OEM PROD. NO.
IMPORTANT ENGINE INFORMATION
THIS ENGINE MEETS U.S. EPA AND CA 2005
AND LATER AND EC STAGE II (SN:4) EMISSION
REGS FOR SI SMALL OFF–ROAD ENGINES
N11236
Figure 16. Family Number Location.
Figure 17. Carburetor (CH18-23,CH620-CH730,CH740).
Troubleshooting
If engine troubles are experienced that appear to be fuel
system related, check the following areas before
adjusting the carburetor.
• Make sure the fuel tank is filled with clean, fresh
gasoline.
• Make sure the fuel tank cap vent is not blocked and
that it is operating properly.
EFI Engines: A special fuel line, capable of
withstanding the high pressure of the EFI fuel system,
is used (must meet SAE R9 specifications). See Figure
15. If fuel line must be replaced, see your Kohler
Engine Service Dealer.
Low Idle
Speed Adj.
Low Idle
Fuel Adj.
Needle &
Fixed Main Jet
(under optional
solenoid)