Fuel System Troubleshooting Guide (Gasoline); Fuel Filter; Fuel Pump - Kohler CV11-16 Service Manual

Section 5
Fuel System and Governor
1. Check for the following:
a. Make sure the fuel tank contains clean, fresh,
proper fuel.
b. Make sure the vent in fuel cap is open.
c. Make sure the fuel valve is open.
2. Check for fuel in the combustion chamber.
a. Disconnect and ground spark plug lead.
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 flow from the tank to the fuel pump.
a. Remove the fuel line from the inlet fitting of
the fuel pump.
b. Hold the line below the bottom of the tank.
Open the shutoff valve (if so equipped) and
observe flow.
4. Check the operation of fuel pump.
a. Remove the fuel line from the inlet fitting of
the carburetor.
b. Crank the engine several times and observe
flow.

Fuel Filter

Some engines are equipped with an in-line fuel filter.
Visually inspect the filter periodically, and replace when
dirty with a genuine Kohler filter.

Fuel Pump

Some engines are equipped with an optional
mechanical fuel pump.
The fuel pump body is constructed of nylon. The nylon
body insulates the fuel from the engine crankcase.
This prevents the fuel from vaporizing inside the pump.
Operation
The mechanical pump is operated by a lever which
rides on the engine camshaft. The lever transmits a
pumping action to the diaphragm inside the pump
body. On the downward stroke of the diaphragm, fuel
is drawn in through the inlet check valve. On the
upward stroke of the diaphragm, fuel is forced out
through the outlet check valve. See Figure 5-1.
5.2

Fuel System Troubleshooting Guide (Gasoline)

Test 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 flow from the fuel tank (Test 3).
3. If fuel does flow from the line, reconnect line and
check for faulty fuel pump (Test 4).
If fuel does not flow from the line, check for
clogged fuel tank vent, fuel pickup screen, shutoff
valve, and fuel lines.
4. If fuel does flow from the line, check for faulty
carburetor. (Refer to the "Carburetor" portions of
this section.)
If fuel does not flow from the line, check for
clogged fuel line. If the fuel line is unobstructed, the
fuel pump is faulty and must be replaced.
Outlet Check Valve
Diaphragm
Figure 5-1. Cutaway - Typical Fuel Pump.
Camshaft
Fuel Pump
Lever
Inlet Check Valve