I recently did a ground up restoration of a 4 stroke 1970 PC50. I thought that I had done everything correctly during the restoration (including new piston rings and a good cleaning of the carb) but I can't seem to get the ped to maintain a constant cruising speed of much more than 35kmh
I know it's got good compression and spark, so I figure it's the carb, but I could be wrong.
The carb in question is a Keihin which uses a sperate main-jet and idle-jet system.
I've tried various combinations of settings on the carb, as well as adjusting the valve tappet clearance on the intake valve and I'm now at a loss as to what to do.
Any advice would be greatly appreciated.