Kohler K91 Service Manual page 27

FUEL SYSTEM AN D GOVERNOR
FUEL SYSTEM - GASOLIN E
The typical gasoline fuel system and related com­
ponents include the f uel tank with vented cap ,
shutoff valve with screen , in-line fuel filte r , fuel
pump (some models) , carburetor and intercon­
necting fuel line .
Ope ration
The fuel from the tank is moved through the
screen and shutoff valve , in-line filter and fuel
lines by the fuel pump (if so equipped) o r g ravity.
Fuel enters the carburetor float bowl and is moved
into the carburetor body where it is mixed with air.
The fuel-air m ixtu re is d rawn into the combustion
Test
1 . C h e c k for the f o l l owi n g :
A . Make sure the tank contains fuel.
B .
Make sure the fuel cap vent i s open .
C . Make sure the fuel shutoff valve is open .
2 .
C h eck f o r fuel I n the c o m b u s t i o n c h a m ber.
A . Disconnect the spark plug lead .
B .
Close the choke on carburetor.
C . Crank the engine several times .
D . Remove the spark plug and check for fuel at tip .
3 .
C h e c k for fuel f l ow from tank t o f u e l p u m p .
A . Remove fuel line from inlet fitting at fuel pump .
S .
Hold line below bottom o f tank. Open shutoff
valve and observe flow.
4 . C h e c k o peration o f f u e l p u m p
A . Remove fuel line from inlet fitting at carburetor.
B .
Crank engine several times and observe flow .
SECTION 6
chamber where it is compressed , then ign ited by
the spark plug .
T roubleshooting
Use the following procedure to check that fuel is
reaching the combustion chamber.
&
WARNING:
Gasoline may be present in the carburetor and fuel
system. Gasoline is extremely flammable and it can
explode if ignited. Keep sparks, open flames, and
other sources of ignition away from the engine. Dis­
connect and ground the spark plug lead to prevent
the possibility of sparks from the ignition system.
2 .
If there Is fuel at tip of spark plu g , fuel is reaching the com-
bustion chamber.
If there Is no fuel at tip of spark plug , check for fuel from the
fuel tank. (Test 3 ) .
3 .
I f fuel does flow from line, check for faulty fuel pump.
(Test 4 ) .
If fuel does not flow from line , check for clogged fuel tank
vent, shutoff valve screen , and fuel lines.
If the fuel tank cap vent does not allow air to escape from
the tank, modify the vent for proper operation by cutting
1 132 "
to 1 1 1 6 " off the bottom . Refer to Figure 6-1 .
4 . If fuel does not flow from line, check for clogged fuel lin e . If
line is unobstructed , fuel pump Is faulty and must be re-
place d .
I f fuel d o e s flow from fuel line, the carburetor probably Is
fault y . Refer to the · Carburetor " portion of this section .
Explosive Fuel!
Conclusi 9 n
6 . 1