With these carbs take the air cleaner off and see if the top of the carb moves. If it does you will have to take it off and tighten the screws from the bottom. This is a common problem with these. Then if thats' ok let it get cold and keep the air cleaner off open the throttle once and see if the choke plate closes. If it does you are ok. There shold be a vacuum pull off that when you start the car up should open the plate just a tad. If thatdoes it then you are ok. If not replace the choke spring belwo the carb that heats up as you drive. You might need a carb overhaul.