My father, who was just about the wisest man I've ever met, as well as the best carburetor rebuilder, had a comment about automatic chokes- - - -"They're smarter than all drivers, and most mechanics!" A properly adjusted automatic choke KNOWS when the engine needs a richer mixture, and provides it at exactly the right time and amount. It never forgets to release itself, as long as you provide it with a little heat to tell it when the engine is warmed up sufficiently that it doesn't need the richer mixture. Wrapping a few turns of copper tubing around the exhaust pipe and plumbing the air that passes through it to the choke housing is a pretty foolproof method of providing that heat to the choke coil so it can release at the right time.
Jerry
