Kohler Comand Pro CH1000 Service Manual page 32

Section 5
Fuel System and Governor
Fuel Line
These engines use low permeation rated fuel lines,
certifi ed to comply with California and U.S. EPA
evaporative emission requirements. Fuel lines that do
not meet these requirements may not be used. Order
replacement hose through a Kohler Service Center.
Troubleshooting – Fuel System Related Causes
1. Check the following:
a. Make sure the fuel tank contains clean, fresh,
proper fuel.
b. Make sure the vent in fuel tank cap is open.
c. Make sure the fuel valve is open.
d. Make sure the fuel lines to fuel pump are
secured and in good condition.
2. Check for fuel in the combustion chamber.
a. Disconnect and ground spark plug leads.
b. Close the choke on the carburetor.
c. Crank the engine several times.
d. Remove the spark plug and check for fuel at
the tip.
3. Check for fuel fl ow from the tank to the fuel
pump.
a. Remove the fuel line from the inlet fi tt ing of
the fuel pump.
b. Hold the line below the bott om of the tank.
Open the shut-off valve (if so equipped) and
observe fl ow.
4. Check the operation of the fuel pump.
a. Remove the fuel line from the inlet fi tt ing of
the carburetor.
b. Crank the engine several times and observe
fl ow.
Fuel Pump
General
These engines use either a mechanical fuel pump, or
optional remote-mounted electric fuel pump assembly.
See Figures 5-1 and 5-2. Operation of the mechanical
fuel pump occurs by direct lever/pump actuation off
rocker arm movement. The pumping action causes the
diaphragm on the inside of the pump to pull fuel in on
its downward stroke and to push it into the carburetor
on its upward stroke, internal check valves prevent
fuel from going backward through the pump.
5.2
Test
Fuel System Tests
When the engine starts hard, or turns over but will
not start, it is possible that the problem is in the fuel
system. To fi nd out if the fuel system is causing the
problem, perform the following tests.
Conclusion
2. If there is fuel at the tip of the spark plug, fuel is
reaching the combustion chamber.
If there is no fuel at the tip of the spark plug,
check for fuel fl ow from the fuel tank (Test 3).
3. If fuel does fl ow from the line, check for faulty
fuel pump (Test 4).
If fuel does not fl ow from the line, check the fuel
tank cap vent, fuel pickup screen, in-line fi lter,
shut-off valve, and fuel line. Correct any observed
problem and reconnect the line.
4. If fuel does fl ow from the line, check for faulty
carburetor. (Refer to the Carburetor portions of
this section.)
If fuel does not fl ow from the line, check for a
clogged fuel line. If the fuel line is unobstructed,
check for overfi lled crankcase and/or oil in pulse
line. If none of the checks reveal the cause of the
problem, replace the pump.
Figure 5-1. Mechanical Fuel Pump.
Fuel
Pump