# Craftsman 5HP snowblower backfires



## hazzardus (Feb 12, 2009)

A friend of mine has a 5 or 6 year old Craftsman 5HP snowblower that idles ok at low and high RMP. However it backfires as soon as the auger is engaged and the motor is put under load. He bought a new carb and put it on with the same result. We were going to work on it over the weekend. I don't know the brand of motor of anything like that. Could it be something simple like the wrong sparkplug?


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## paulr44 (Oct 14, 2008)

If it's really old, more than likely it needs ignition points and condensor. There could be other issues, such as a blown head gasket, bent flywheel key but we'd need to know more about the engine and ambient conditions. For instance, if you're running it in warmer weather, it may be overheating. The heater box over the carb. is designed to prevent carb. icing and keep the gov. linkage from icing up as well, but can cause overheating above 40 degrees F. The wrong spark plug could lead to detonation, so you'd have to tell us more, such as if it does it when the engine is still cold, or only when hot etc.


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## justin3 (Apr 10, 2007)

Paul I think you missed what he said, a 5-6 year old machine wont have points and condenser  Im guessing your engine is a tecumeh, thats mainly what sears uses especially 5 or 6 years ago. How bad is the backfire and does it stall the engine? It sounds like a valve issue to me or possibly a blown head gasket like Paul said.


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