Fred, The Y1 carb is famous for loosening up from its bell, causing intermittent vacuum leaks. With the engine running at idle, take off the air cleaner. Grab the top of the carb, and try to rock it back and forth, side to side. If the engine rates changes, the carb is leaking air. Take the carb off, and tighten the screws that hold it together. Most are located underneath. I have to do this to my carb about once a year. Wade 73 Gremlin, 78 Pacer DL, 51 Rambler Conv. [Non-text portions of this message have been removed]