Definitely try carb cleaner or something near the intake to head area, underside by the valley pan, and around the base of the carb.
Like others have mentioned, it’s either too lean or the timing is retarded. You’ve verified the timing mark with a piston stop so that is likely ruled out, but if it doesn’t die with your hand covering the carb it sounds like it’s getting excess air somewhere.
Whenever we have a new engine that shows signs of being lean (won't idle on idle circuit, red headers, runs like chit) I grab a can of crab cleaner and spray the intake mating area and carb base. You will know right away with the engine speed change.
Joe
Last edited by sr4440; 05/29/2308:45 AM.
Without Data, you’re just another guy with an opinion.
