I fitted the carburettor back on my 1641 after an oil seal replacement and stainless exhaust upgrade turned into a cracked head discovery and valve replacement and a flwheel dowel replacement when I tightened the flywheel finger tight. I felt that there was a strange feel to the throttle pedal and it was hard to get to 70 mph. But it still accelerated well. But it wouldnt start when it was left hot for about half an hour. I just decided to clean up the carburettor in case it was dirt in the fuel valve. I put it back and noticed the choke linkage was stopping the throttle opening properly. So I took the carb off and the throttles opened normally. The penny dropped . I had put a clamp on the vacuum hose . The screw on the clamp was sticking out and blocking the choke mechanism which moves with the throttle - which stopped the throttle going above half open. I rotated the clamp and now I have full throttle. I thought I would post this.. I think I have heard of others with similar mystery progressive problems.
