backfiring

[persof 14]

My C-161a frequently backfires when I shut it off. Any ideas on how to correct this?

A modest leaning of the low speed needle on my 312-8 correcrted it's backfiring but if I do that on the C-161a it will not transition up to full RPM???

Thanks

Francis

[MikesRJ 552]

I'm no expert, but here goes ...

Backfiring is normally caused by a fuel issue or a timing issue. Assuming the engine is mechanically sound (the assumption here is referring to a valve or other internal mechanical issue) and there are no mechanical issues, check the following:

Engine Timing:

See this process - http://www.mywheelhorse.com/graphics/file/...ngineTiming.pdf

Fuel System:

Check the fuel filter, check the fuel pump, check the fuel lines, check any fuel shut-off valves, and/or clean the carburetor - http://www.mywheelhorse.com/graphics/file/...etorRebuild.pdf

[JimD 3,345]

Sometimes the backfire is caused by glowing rusty embers in the muffler igniting unburned fuel from the engine idling down. Some suggest shutting it off at full throttle. I disagree with this. I always idle down and let the engine run for a minute at idle before shutting it off. This works for my tractors, might for yours too. :thumbs:

[mavfreak 11]

Is this a Briggs twin?

[JC 1965 1,528]

I don't know if it has anything to do with your problem but I agree with Jim. I always idle mine down before turning them off. Just my 2 cents worth!! :thumbs:

[persof 14]

I do allow idle time before shut down and it had a new muffler. It is a 16HP Kholer and I have not had a chance to check the timing (dave a dewll meter but no timing light)

Thanks

Francis