I have an old 440 that I just made a 440/460 hybrid. I put a brand new carb on it when I did the swap because when it was just a 440 I couldn't ever get the carb adjusted correctly, or so I thought. The 440 piston was also absolutely shot so I never really thought about the issue being anything other than that or the carb. But now with a brand new jug, piston, and carb it still does it. Is it my clutch springs? Or does anyone have any idea? It's holding compression at 160, starts right up, but it just runs and runs and runs. Even when the engine audibly sounds like a decent idle the chain will not stop. It's really starting to piss me off so any help would be appreciated haha.