Post by
ravera »
https://forums.nicoclub.com/ravera-u137799.html
Tue Jul 14, 2009 5:48 pm
Weber automatic choke, as many do, use a bi-metallic spring similar to a thermostat. When the engine has been off for a while, the spring is cold and it holds the choke on. When you start the engine it feeds +12 to the single contact (the carb is grounded to the rest of the motor so just put the -12 on the carb body) it slowly heats the bi-metallic strip causing it to un-coil and slowly open the choke. To see if it works, first see if it is in the "choke" position when it's cold, and then put 12v across it to see if it heats up. It wont be instant and it will probably take a few minutes, should be more when it's cold since the spring starts from a colder temp.
Bob