While mowing with the Cub, the engine died, but restarted OK. It then kept dying. Suspecting a fuel problem, I did all of the easy stuff, Sediment bowl, inlet screen, fuel flow check and all was OK. I then noticed the governor rod would not move the throttle. I removed the carb, and found that the butterfly was contacting the manifold and jamming. This has never been a problem before. The carb is a Zenith, not the original IH. I bought it that way. I'm guessing its the wrong one since the carb diameter is larger than the manifold. I guess over time the gaskes squished enough to allow contact. I never had a problem with this until now. Oh well, I guess i'm in the market for a replacement now.