Kohler Courage SV710-740 Service Manual page 37

Main Circuit: (See Figure 5-3) At high speeds/loads the engine operates 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 airflow, 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; no
adjustment is possible.
Fuel Inlet
Float Valve Seat
Float Valve
Main Jet
Figure 5-3. Main Circuit (Typical).
Idle Speed
(RPM)
Adjustment
Screw
Float
Main Emulsion
Hole
Main Air Bleed Jet
Choke Valve
Bowl Vent
Fuel System and Governor
Keihin
Carburetors
Only
Throttle Valve
Main Nozzle
Main Jet
Fuel Shut-Off Solenoid
with Main Jet
Section 5
Air
Fuel
Mixture
5
5.5