Kohler COMMAND CV17-745 Service Manual page 40

Kohler Engine Parts Call K&T 606-678-9623 or 606-561-4983
Section 5
Fuel System and Governor
Troubleshooting Checklist
When the engine starts hard, runs roughly or stalls at
low idle speed, check the following areas before
adjusting or disassembling 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.
• Make sure fuel is reaching the carburetor. This
includes checking the fuel shut-off valve, fuel tank
filter screen, in-line fuel filter, fuel lines and fuel
pump for restrictions or faulty components as
necessary.
• Make sure the air cleaner base and carburetor
are securely fastened to the engine using gaskets
in good condition.
• Make sure the air cleaner element (including the
precleaner if equipped) is clean, and all air
cleaner components are fastened securely.
• Make sure the ignition system, governor system,
exhaust system, and throttle and choke controls
are operating properly.
If the engine is hard-starting, runs roughly or stalls at
low idle speed, it may be necessary to service the
carburetor.
High Altitude Operation
When operating the engine at altitudes of 1500 m
(5000 ft.) and above, the fuel mixture tends to get
over-rich. This can cause conditions such as black,
sooty exhaust smoke, misfiring, loss of speed and
power, poor fuel economy, and poor or slow governor
response.
To compensate for the effects of high altitude, special
high altitude jet kits are available. The kits include a
new main jet, slow jet (where applicable), necessary
gaskets and O-Rings. Refer to the parts manual for the
correct kit number.
Fuel Shut-off Solenoid
Some carburetors are equipped with an optional fuel
shut-off solenoid. The solenoid is installed in place of
the bowl retaining screw. The solenoid has a spring-
loaded pin that retracts when 12 volt current is applied
to the lead. When it is extended, the main fuel jet is
blocked, preventing normal carburetor operation.
5.6
Below is a simple test, made with the engine off, that
can determine if the solenoid is functioning properly:
1. Shut off the fuel and remove the solenoid from the
carburetor. When the solenoid is loosened and
removed, gas will leak out of the carburetor. Have
a container ready to catch the fuel. The main jet is
mounted in the tip of the solenoid pin. Be careful
that it does not get damaged while the solenoid is
separated from the carburetor.
2. Wipe the tip of the solenoid with a shop towel or
blow it off with compressed air, to remove any
remaining fuel. Take the solenoid to a location
with good ventilation and no fuel vapors present.
You will also need a 12 volt power source that can
be switched on and off.
3. Be sure the power source is switched "off".
Connect the positive power source lead to the red
lead of the solenoid. Connect the negative power
source lead to the solenoid body.
4. Turn the power source "on" and observe the pin in
the center of the solenoid. The pin should retract
with the power "on" and return to its original
position with the power off. Test several times to
verify operation.
Figure 5-4. Fuel Shut-off Solenoid Location.
Carburetor Adjustments
General
The carburetor is designed to deliver the correct fuel-
to-air mixture to the engine under all operating
conditions. The high speed mixture adjustment is set
at the factory and cannot be adjusted. The low idle fuel
adjusting needle (some models) is also set at the
factory and normally does not need adjustment.
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Fuel Shut-off
Solenoid