1949 Electric Sisson Choke

[Branded]

There must be something wrong with my vehicle's Sisson, when I got the car, I noticed the wire from the starter to the Sisson was not connected, I connected it and it promptly melted when cranking the engine. So the electrical part must be shorted out. But the thermostatic part still works in that the choke plate is closed when cold and fully open when hot.

My car starts easily when cold and ok if I use the proper pedal technique when hot (crank for about 5 sec and then slowly add throttle).

So am I correct in stating that the current from the starter shuts the choke when cranking (no matter what the temperature of the engine) to make it easier to start a hot engine?[/unquote

So, the proper technic for starting is to (crank for about 5 sec and then slowly add throttle).

Edited August 20, 2015 by Branded

[meadowbrook]

So I am still unclear, what is the purpose of the electric component of the sisson choke if the thermostatic spring already is positioning the choke plate in the proper position depending on the temperature?

[DonaldSmith]

Sisson choke - half & half.  The solenoid closes the choke plate partially, for extra mixture when starting (and setting the higher speed idle).  The bimetallic strip closes the choke plate partially, til the engine warms up.