Choke Thermostat/Heater: Description and Operation

Fig.21 Electric Assist Choke System:

Fig.22 Electric Assist Choke System:

Fig.23 Choke Heating Element:

Description
The electric assist choke, Figs. 21 and 22, is used to reduce carbon monoxide (CO) and hydrocarbon (HC) emission during engine starting and warm-up. The choke thermostatic coil spring reacts to engine temperature, however, an electric heating element next to a bimetallic spring in the choke well will assist engine heat to shorten choke duration, Fig. 23.

The wattage of the choke heater is part of the choke calibration and may change from year to year.