5.3
Section 5
Fuel System and Governor
5
Figure 5-3. Keihin Two-Barrel Carburetor.
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
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 adjust or
service the carburetor.
Figure 5-2. Optional Electric Fuel Pump.
Fuel Pump - Replacement
Replacing the Mechanical Fuel Pump
The mechanical fuel pump is an integral part of the
valve cover assembly and not serviced separately. See
Figure 5-1.
1. Disconnect the fuel lines from the inlet and outlet
fittings. Note orientation.
2. Follow the procedure for replacing the valve
cover (see Sections 8 and 10).
3. Reconnect the fuel lines to the inlet and outlet
fittings and secure with the clamps.
Carburetor
General
Engines in this series are equipped with a Keihin BK
two-barrel, side-draft carburetor with fixed main jets
on a matching intake manifold. The carburetor
features a self-relieving choke, serviceable slow jets,
main jets, bowl drain and a fuel shutdown solenoid.
See Figure 5-3.
WARNING: Explosive Fuel
Gasoline is extremely flammable and its vapors can explode if
ignited. Store gasoline only in approved containers, in well
ventilated, unoccupied buildings, away from sparks or flames.
Do not fill the fuel tank while the engine is hot or running,
since spilled fuel could ignite if it comes in contact with hot
parts or sparks from ignition. Do not start the engine near
spilled fuel. Never use gasoline as a cleaning agent.
Self-Relieving
Choke
Fuel Shut-Off
Solenoid
Slow Jets
Bowl Vent
Low Idle Fuel
Adjustments
(With Limiters)
