bobusnick104
Member
I just had that problem. Sounded like chipmunks in a cage. Only heard it when there was high vacuum, like at idle. It was a vacuum leak between the carb and manifold. I removed the Tillotson carb and checked the flange flatness with a straight edge. It showed about .040" gap. With the carb in a vise, I used a file to face off the flange. Then checked the manifold for flatness and it was ok. New gasket and sealer and back on the road.