If the carb your working with has the round choke heater on the passenger side, you can easily convert to an electric choke. Remove the factory hot air style heater, remove the gasket, ideally you should remove the hot air tubes (you can leave the heater part I the manifold) and block the small internal vacuum port in the back of the housing. Then install the electric heater (make sure you remove the gasket, it grounds thru the housing). With the engine cold, press the gas pedal, the choke plate should close. Rotate the heater until there is a slight tension holding the plate closed. Then, use a hand vacuum pump to apply vacuum to the choke pull off. The choke plate should open a little. The exact amount it opens varies by engine, options, year, etc. Apply SLIGHT closing pressure to the choke plate (to eliminate slop in the linkage messing with your adjustment) and adjust the serscrew on the pull off to open the choke about 3/16 inch. Disconnect the vacuum pump, the choke should fully close again. Reinstall the pull off vacuum hose, start the engine. The choke pull off should open the choke plate slightly. As the engine runs, the choke should continue to open. After a few minutes, the choke should be fully open. You may need a few cold starts to dial in the “happy place” with the choke pull off. If it starts and then almost immediately begins to load up and puff black smoke from the exhaust, the engine needs a little more air, adjust the pull off screw to open the choke plate a little more. If it starts, then dies, or dies when you put it in gear, or dies when you try to accelerate (engine is lean) the choke plate may need to be closed a little more. Like I said, it may take several cold starts to get it right.
Once the engine is fully warmed up, then adjust idle mixture. With the engine off, lightly seat both mixture screws, then back them out evenly about 2 1/2 turns. Start the engine, pick one mixture screw, turn it in out out about half a turn. Pay close attention to the idle speed, hopefully you can detect a change in speed. The idea is to adjust the mixture screws evenly until you have the highest idle speed. Once that’s done, reset idle speed wherever it’s desire, then readjust the mixture screws again, going maybe 1/8 turn at a time. Once that’s done hopefully it idles smoothly, at a low enough speed, and doesn’t die when you put it in gear. Good luck!!
