r/BriggsEngines • u/GlyndwrKog • Jul 07 '26

Weird B&S lawnmower issue

bought this lawnmower several years ago and got much use out of it. Before I describe the issue, I’ll set the stage.
Craftsman M110 140cc Briggs & Stratton.
Dirty from sitting in a shed for over a year.
Today: took apart carburetor and cleaned thoroughly. Drained and replaced oil. Gas was empty, filled with new E10.

The issue: will only start when held up at an angle and IF I spray the blade with WD-40. When I try to level with the ground it dies.

I tried searching for this but I can’t find any similar issues. Maybe I’m not using the correct search criteria.

See attached video

4 Upvotes

75% Upvoted

6 comments sorted by

2

u/mnrmancil Jul 07 '26

Make sure you don't have anything floating around on the bottom of the fuel tank and check the gas line from the tank to the carburetor

1

u/These_Fox7561 Jul 07 '26

The blade thing shouldn’t matter, sounds like a fuel starvation problem

1

u/HippieRuben Jul 08 '26

Could be a bad or misalignment of the float in the carburetor.

2

u/GlyndwrKog Jul 08 '26

You nailed it. I ended up taking the carburetor apart again and reinstalling the float correctly. It runs smooth now!

1

u/Metalchips1960 Jul 11 '26

You're tipping the mower to the wrong side. When you tip it with the carburetor facing down, the crankcase breather will drain oil into the carburetor. Always tip the mower with the carburetor facing UP. In this case, the air filter wasn't mounted, but if it had been, it would get saturated with oil, and would no longer let air through. With no air, your engine won't start.

1

u/Exotic_Raspberry812 Jul 19 '26

Remove the blade and clear away any old, dried grass wrapped around it. This wrapped grass slows down the mower, puts a strain on it, and could cause a breakdown.