Filter
Top Products
5.5
Section 5
Fuel System and Governor
5
Main Circuit: (Figure 5-3) At high speeds the engine operates mostly on the main circuit. As a metered amount
of air is drawn through the main air bleed jet, fuel is drawn through the main jet. The air and fuel are mixed in the
main nozzle and then enter the main body of air flow, where further mixing of the fuel and air takes place. This
mixture is then delivered to the combustion chamber. The carburetor has a fixed main circuit. There is no
adjustment feature present.
Figure 5-3. Main Circuit.
Check Valve Spring
Outlet Check Valve
Leak Jet
Adjustment Screw
Diaphragm Spring
Pump Diaphragm
Inlet Check Valve
ACCELERATOR PUMP
ASSEMBLY
(Some Carburetors)
Fuel Shut-Off Solenoid
with Main Jet
Main Jet
Main Nozzle
Throttle Valve
Choke Valve
Main Air Bleed Jet
Accelerator Pump Nozzle
Bowl Vent
Fuel Inlet
Float Valve Seat
Float Valve
Main Jet
Float
Main Emulsion
Hole
Idle Speed
(RPM)
Adjustment
Screw
Air
Fuel
Mixture