Carburetor Operation; Float System; Pilot Jet System; Main Jet System - Cushman HAULER 800X Technician's Repair And Service Manual

FUEL SYSTEM
Read all of Section B and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
B
Leave 1" airspace
for ventilation
Fig. 2 Fuel Tank

CARBURETOR OPERATION

The carburetor consists of four different systems:
• Float
• Pilot jet
• Main jet
• Choke

Float System

The float chamber is located on the underside of the car-
buretor and the correct fuel level is maintained by
means of the float and needle valve.
As the fuel flows from the fuel pump it must pass
through the needle valve and into the float chamber. As
the fuel enters the float chamber, the float starts to rise
against the needle valve. When the buoyancy of the
float exceeds the fuel pressure on the needle valve, the
float closes the needle valve. The float is not adjustable
to maintain the correct fuel level within the float cham-
ber. As fuel is consumed from the float chamber, the
float drops which allows the needle valve to admit addi-
tional fuel.

Pilot Jet System

The pilot jet system function is to deliver fuel to the
engine during low speed operation. The fuel flow is
determined by the pilot jet size and the setting of the
pilot screw.

Main Jet System

The main jet system function is to deliver fuel to the
engine during acceleration and heavy load conditions.
Fuel flow is determined by the main jet size. Air is mixed
with fuel that passes through the bleed opening in the
main nozzle. This mixture passes into the carburetor
venturi as atomized air/fuel and is mixed with intake air
and delivered to the engine.
Page H-2

Carburetor Service

Be sure that the ignition system is functioning correctly
FUEL
before determining that servicing the carburetor is
required. Refer to ELECTRICAL section for ignition sys-
tem information.

Choke System

The choke functions to make initial starting of the engine
easier in cold weather conditions. The choke plate
restricts the air flow into the carburetor which enriches
the air/fuel ratio.

Choke Operation

Pull the choke knob (10) out to operate the choke (Ref.
Fig. 3). Check that the cable operates smoothly and that
the cable returns when the knob is released. The motion
should be smooth throughout the entire operating range.
If there is any binding or sharp bends, the choke cable
assembly must be replaced.
Do not attempt to lubricate the choke cable. Lubricant tends to
retain dirt on the moving parts which will cause premature
deterioration of the cable.
Repair and Service Manual
(Ref. Fig. 3)
NOTICE