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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 28074
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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I have a 13.5 &S that back fires through the muffler and the

Customer Question

I have a 13.5 B&S that back fires through the muffler and the carb but will not start
Submitted: 2 years ago.
Category: Small Engine
Expert:  Curtis B. replied 2 years ago.
Welcome to JUST ANSWER small engines, let me try to help you !! Backfiring is indication that the valve is open when the spark occurs. You either have a valve that is not closing completely, which you would check by checking the compression. Or it is out of time, and the flywheel to crankshaft key has sheared. Checked by removing the flywheel nut , to see if the slots in flywheel and crankshaft are in perfect alignment. Has the engine been stopped by hitting an object? If so, timing key is sheared.