Thanks Don, unfortunately I've been down that road a few times now, I also tried propane, but no affect on engine RPM. This weekend I attempted to seal (tighten up the internal bearing surface on the throttle valve) with some 3M as a test, but no real difference.. I'll keep trying, need to check the timing again and I just purchased a vacuum gauge..
I've also been looking around for a Carter W-1 again.
thanks again