8 HP Briggs and Stratton Flaming Exhaust!!!!!

todd8 · Sep 28, 2017

Need some help!!! Have an old model 8HP Briggs and Stratton, pull start, solid state ignition motor that decided it wanted to start shooting flames out of the muffler when I shut it off today. I noticed the inside of the muffler glowing, which is why I shut it down, and immediately upon doing so, had flames greeting me!!

I am thinking possibly an exhaust valve sticking, but before I tear into it, thought I would ask for some advice?

Thanks in advance!!!

T.R.K. · Sep 28, 2017

Does it ever backfire?

Its not running too lean is it? Does it surge when its running, either at speed or at idle? If it does, the carburetor is too lean. And a lean mixture will cause the exhaust and muffler to run extra hot.

It could also be a burnt valve or seat, or the exhaust valve has no running clearance when hot. It might pay to adjust the valves.

The reason you had flames is when you turn the switch off, it stops the spark but the engine continues to spin and pull fuel from the carburetor through the engine for a few revolutions as it comes to a stop. The fuel goes through the engine and into the exhaust. The red hot spots in the muffler caused it to flame.

Bob · Sep 29, 2017

hck the flywheel key. If sheared making timing "late", exhaust will be HOTTT!

W_B · Sep 29, 2017

Some people pay to have their machine spit flames!

Pete in Holland MI · Oct 12, 2017

ALWAYS idle down any engine that has been under a load for 30 seconds or so before turning it off & allow it to cool off some. As
said earlier, spark is turned off, but gas & air still pour in, often causing a big explosion out of your muffler.

Don B. · Nov 4, 2017

real actual flames out the exhaust? COOL!

8 HP Briggs and Stratton Flaming Exhaust!!!!!

todd8

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T.R.K.

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Bob

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W_B

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Pete in Holland MI

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Don B.

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