Briggs 17.5 OHV Backfiring

[Butch1957]

I have re-lapped the valves, I have replaced the spark plug & fuel filter, I have replaced the needle and bowl gasket & I have flushed out the gas tank and used Hi Octane fuel. My problem is that when I turn off the ignition key, there is a Pop / Backfire thru the muffler. I have connected the two wires that go to the fuel solenoid. Everything seems to be okay. It starts easy and runs good except when I turn the ignition key to the Off position is when the engine makes a Popping Noise.

Any suggestions ?

Please.

Thanks.

 

[pugaltitude]

Sounds as though the antifire solenoid is not working.
The backfire that you are hearing is fuel hitting the exhaust which is still getting sucked into the engine as the engine is slowing down and stopping.
The solenoid is maybe stuck in the open position.

You could also try putting throttle control to idle before switching off.

 

[scott47429]

i always idle mine down as low as it will go and let it idle for like 30 sec. then turn it off and it don't back fire if i don't it sounds like a shot gun going off