# B&S twin backfire



## danielson (Feb 11, 2005)

Got a 14HP Briggs seems to run good on idle and full throttle. When I idle down, and turn key off, it backfires. Could anyone tell me why this is. Thanks


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## bugman (Aug 12, 2004)

has it always done it since new?? i wouldn't worry much about it then if it has always done it. if it just started it could be it needs a good tune up. most will cut the mowers off at full throttle and start on low when warmed up. i have sometimes my old 8hp briggs do it, nothing wrong with it, it just does it. i've seen perfectly good new ones do it. but i've seen old ones do it because they needed a very good tune up. valve check, head cleaning, etc.


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## danielson (Feb 11, 2005)

Thanks I'll try valve clearance


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## Bowman's (Dec 16, 2004)

Does it have an anti backfire valve under the carb bowl? If it does and it is not closing when you turn the key off it lets fuel into the cylinder as the motor stops which puts raw fuel in the muffler, raw fuel in a red hot muffler will burn, that is what is backfiring. If the carb is to rich or the fuel needle is not closing on the seat that will let raw fuel into the cylinder and out to the muffler that will backfire. Hope this helps. Mike


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