26
Fuel System
KohlerEngines.com
22 690 01 Rev. --
Typical carbureted fuel system and related components
include:
● Fuel tank.
● Fuel lines.
● In-line fuel fi lter.
● Fuel pump.
● Carburetor.
Fuel from tank is moved through in-line fi lter and fuel
lines by fuel pump. On engines not equipped with a fuel
pump, fuel tank outlet is located above carburetor inlet
and gravity moves fuel. Fuel then enters carburetor
fl oat bowl and is drawn into carburetor body and mixed
with air. This fuel-air mixture is then burned in engine
combustion chamber.
FUEL RECOMMENDATIONS
Refer to Maintenance.
FUEL LINE
Low permeation fuel line must be installed on carbureted
Kohler Co. engines to maintain EPA and CARB
regulatory compliance.
FUEL PUMP
Some engines are equipped with an optional pulse fuel
pump secured on a bracket installed on blower housing.
Fuel pump has two internal chambers separated by
a diaphragm. Air chamber is connected to engine
crankcase by a rubber hose. Fuel chamber has an inlet
from fuel tank, and an outlet to carburetor. Inlet and
outlet each have an internal, one-way check valve.
Alternating negative and positive pressures in crankcase
activate pump. When piston moves upward in cylinder,
negative pressure (vacuum) is created in crankcase
and in air chamber of pump. Diaphragm fl exes toward
negative pressure, and suction draws fuel past inlet
check valve, into fuel chamber. Downward movement
of piston causes a positive pressure in crankcase and
air chamber, pushing diaphragm in opposite direction,
putting pressure on fuel. Inlet check valve has now
closed, so fuel is forced past outlet check valve, to
carburetor.
Repair
Pulse fuel pumps are not serviceable and must be
replaced when faulty.
Removal
1. Turn knobs toward unlock symbol and remove air
cleaner cover.
2. Disconnect inlet, outlet, and pulse lines from fuel
pump. Mark lines for proper reassembly.
3. Remove fuel pump from bracket.
Installation
1. Install new fuel pump, pressing fuel pump onto
bracket past locking tabs.
NOTE: If necessary, carefully rebend locking tabs to
ensure fuel pump is secured.
2. Connect inlet, outlet, and pulse lines to their
respective fi ttings on pump. Secure with clamps.
3. Position air cleaner cover on housing and line up
knobs with unlock symbol. Turn knobs toward lock
symbol to secure.
AUTO CHOKE (IF EQUIPPED)
If engine is equipped with Smart-Choke
TM
, follow
troubleshooting procedures starting on page 32 of this
manual.
