The bowls are interchangeable between carbs as far as fit, but the choke will only work if they are on the correct carb. You said they were on the correct carb once, but are you sure? Some bowls are labeled 1-1 and 1-2 inside of them. 1-1 goes on the carb w/choke lever. Another way to test this is see if you can spray carb cleaner down the little hole the choke rod goes down and see if it shoots out back at you(may want to wear goggles for this Lol) or out another hole in the bowl. You either have the bowls on the wrong carb, or the passage is plugged not allowing your choke to work.