HELP..briggs & stratton popping or backfiring through the carburetor

[dennis morris]

Tried Seafoam Intake cleaner, seemed to help some.
Drove the mower around for a half hour or so after.
Only popped back twice. the can is big enough for 2-3 applications
smoked like crazy for a minute while the carbon was burning off. seemed to smooth out
some.

Will report back in a few days, after spraying it ag

E

Don't have coil on upside down do U?

 

[wjjones]

Bump, kind of curious what the outcome was

Me too. The last one I had do this had a crack in the cylinder wall right at the bottom past the stop point of the rings. It back fired through the carb so much it melted the intake on the right side. I bought it used, and the guy had tried to rebuild it after it threw a rod. It would run but the busted place, and the crack caused it to blow the compression backwards back out through the carb. I ended up getting another engine to rob the top half off of. I put it on the sump pan of this motor, and it runs like a brand new one now. Its the mower in my avatar on the up hill side of the picture dys4500.

 

[briggs]

hit it With a BFH that will fix it

 

[Fish]

i have a craftsman lawn tractor with a B&S 15.5 hp OHV engine, engine model=28N707..type=0173-01.. it had been setting for several years due to a coil problem, i repaired the problem a few weeks ago, the kill wire had grounded out killing the fire, so i put it on a toggle switch, the mower will crank and run, no problem, but it popps or backfires thru the carb, you can see fire in the carb,

Yeah, you should backtrack to the beginning....

 

[Fish]

Can you put up a pic of this "toggle switch"??? Have you tried anything simple like a new plug?????

 

[reynoldston]

The problem you are describing I would say camshaft.

 

[wjjones]

The problem you are describing I would say camshaft.

Yep worn lobes, or missing teeth.

 

[Fish]

Yep worn lobes, or missing teeth.

Hey, you knew my first wife????

 

[wjjones]

Hey, you knew my first wife????

:laughing:..:laughing:.. And mine.:laughing:

 

[wjjones]

A good idea was mentioned though. How does the plug look? If you put in a new one then check it again after you have been trying to start it. See if it is gummed up with oil, carbon, etc. I finally figured out the problem with mine by splitting it from the sump to check everything inside. If you go this route you will need a new sump/ oil pan gasket to put it back together.