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Repair information and troubleshooting for Craftsman-brand riding lawnmowers.

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Backfiring when starting possible causes

What would cause this motor to backfire when starting?

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erniedillon192, check your timing. The how to will depend on what model your mower is and what engine it has. It is possible that your timing is off due to a deformed flywheel key etc.

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backfire is a result of half burned, hot exhaust finding oxygen to finish burning. I'd change the spark plug first. I'm guessing its also hard to start or does it just do this when the engine has been running?

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Yes it is hard to start beside the plug what else would cause backfire?

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somehow your air/fuel mixture isn't right. Specifically would be hard to predict without messing with it. Its possible its not getting enough fresh air to support full burn in the cylinder, When did you change the air filter last?

Next I'd have a look at the carburetor, take off the bowl and see if its all gummed up with crud, if so clean it. If its still giving trouble, you might need to give the carb a good cleaning, which mostly sucks so because I'm lazy I'd try to run some barryman's b12 through it and see if that fixes it first.

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Thank's will try that definitely grateful I'll get back later this week if I still have this problem again Thanks

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erniedillon192 will be eternally grateful.
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