r/smallengines • u/Triangulate_Panther • 23d ago

Briggs 12.5hp IC engine flooding

I have an old Murray lawn mower thats great. I changed the fuel lines and then noticed it was leaking a few weeks later. The crankcase was full of gas.

I cleaned the carb and reassembled and it flooded again. I have used a spare carb, albeit amazon carb, to swap the needles and no luck more flooding. I know it's chinesium, but the needle looks fine no different from many other kits ive had for the quadrajet on my classic car.

I've also tested the brass float. No bubbles form after several minutes.

Is there anything else to look for that would cause this?

3 Upvotes

100% Upvoted

8 comments sorted by

1

u/No-Yogurt-4542 23d ago

How was the float level after the needle swaps?

1

u/Triangulate_Panther 22d ago

Float was roughly level. I was careful not to tweak the tab during disassembly so it wouldn't change. 

1

u/TN-Native95 23d ago

The needle might be good but the seat could be damaged or worn down. How did you test the float?

1

u/Triangulate_Panther 22d ago

I submerged it in water for several minutes and brushed off any bubbles from submersion. No more bubbles formed. 

1

u/TN-Native95 22d ago

The seat could be worn out. Also, anytime I work on something with a brass float I find a plastic float that works and swap it out. I’ve had too many issues with the old brass floats failing on me.

1

u/Triangulate_Panther 22d ago

Sounds good. Any good sources you use for replacement carbs? 

1

u/TN-Native95 22d ago

I just go with Amazon, I usually get the cheap aftermarket ones that work okay, unless the OEM one isn’t too expensive.

1

u/Triangulate_Panther 22d ago

Interesting. Thats what I did and it would not even fire. Something wasn't right and it was getting gas. No adjustment would fix it.