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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 28322
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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Model 317 engine backfires

Customer Question

Model 317 engine backfires
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 !! Does it run? Back fires while it is running? Onan twin engine. Have the valves ever been checked? Backfire is typically spark occurring when a valve is open.

Customer: replied 2 years ago.
Not sure engine type but it runs and when I put a load on it{engage the blade} it backfires and then quits running
Customer: replied 2 years ago.
I suspect maybe exhaust valve not closing completely.
Customer: replied 2 years ago.
Or carbon build-up not allowing valve to fully close
Expert:  Curtis B. replied 2 years ago.

Is engine firing on both cylinders?

Customer: replied 2 years ago.
The info I am giving you is 2nd hand from a 60+ older lady who just wanted the oil changed, new spark plug and blade sharpened. I have not tried the mower myself. Guess I need to go over to her place and find out what's what.
Expert:  Curtis B. replied 2 years ago.
It was just a thought. If engine is running only on one cylinder, it could be overloaded when blades are engaged.