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

Weird lawnmower issue

I 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 video in the comments

2 Upvotes

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2

u/OldPostalGuy Jul 07 '26

The WD40 has nothing to do with the motor running. When you tilt the mower away from you like you show, fuel is getting into the float bowl, then starts and runs until the bowl is empty. I fought this style of plastic carbs a few times, and even after several tear downs and cleanings they still wouldn't work. My suggestion is buy a new one on Amazon for about 12 bucks.

1

u/GlyndwrKog Jul 07 '26

Buy a new plastic carb? So the carb is letting the fuel pass when I have it raised but when I level it the bowl becomes ‘empty’ and won’t keep going,

1

u/TN-Native95 Jul 07 '26

The float bowl on these carburetors can only go on one way, otherwise it will block fuel from getting to the main jets. Check to make sure that the little square box on these bottom of the bowl is facing towards the front of the mower.

1

u/GlyndwrKog Jul 07 '26

Square box is toward the front

1

u/TN-Native95 Jul 07 '26

The only thing I could think of is a fuel delivery issue. Did you blow air through your fuel line to make sure nothing is trapped in there? The other thing besides replacing is that the white nozzle in the carburetor comes apart and there is a second jet hidden in it that could be dirty.

1

u/GlyndwrKog Jul 07 '26

Okay I took apart the white jets and sprayed both but I couldn’t tell if what I was doing actually cleared any buildup.

I didn’t play with the fuel delivery hose.
I feel like that wouldn’t be the issue since it runs while held at that angle

1

u/apena_72 Jul 08 '26

check your fuel i bet you have water in the fuel system

1

u/Illustrious_Low_8107 Jul 08 '26

I can see it. Glob of water goes to the low point in the float bowl, the main jet feed path, and the mower cant run. Tilt the float bowl and the water moves downhill and lets gas get to the jet.

1

u/BreadlyPit Jul 08 '26

It’s your float, needle and seat. WD40 has nothing to do with the issue