Choke Pull-off: Description and Operation

Automatic Choke System:

The automatic choke system is actually three subsystems working as one.

These include:
1. The choke valves and linkages.
2. The choke opener.
3. The fast idle system.

The choke valves are located in the throttle bore of each carburetor. When the engine is not running the angle of the choke blades is determined by the choke thermowax valve. The thermowax valve is connected by hoses to the engine cooling system. As the engine temperature warms up, the wax in the valve expands and opens the choke blades. The fast idle system sets engine speed based on choke blade angle. As the thermowax valve opens the choke blades, the fast idle linkage brings engine speed down to curb idle.