backfire while running


Old 11-10-19, 04:17 PM
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backfire while running

20 hp briggs n stratton v twin........ ive cleaned carby..... muffler.......changed spark plugs...... even reset timing but still back fires hard n mainly running at high rev any ideas
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Old 11-10-19, 04:43 PM
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Intake valve too tight?

Old 11-10-19, 05:07 PM
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Is it popping through the intake or out the exhaust?
Old 11-10-19, 08:31 PM
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I put in 4 new valve guides into a Kohler opposed twin. Developed a hard backfire on start that happened less and less as time went on. I bet if you get it apart you will find a sticky valve, and if you answer the cheese man, you can narrow it down a bit as to which one.
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