Hy DES57, welcome, I can honestly say that never in all my years have I heard of such a symptom. I wouldn't put something like this past a confusilator controlled engine, but a carbureted one? You say when you shift the transmission into neutral the engine returns to idle, no load on the engine and the r.p.m. goes down??? Does this occur as you're coming to a stop or after you're actually stopped? I'll be very interested to follow this thread.
