lawn boy mower drips oil

[Burt]

My mother who lives far from me has a 2-stroke lawn boy mower. Occasionally and on an intermittent basis, it deposits what appears to be a 6x3 inch black oil slick on the garage floor. It comes from underneath the mower, not the side. Some LB's exhaust out the bottom. It otherwise runs ok. Is this symptomatic of a problem? I assume that it is unburned byproducts of combustion that are condensing. Is there anything that can be done to get rid of this nuisance?

 

[IndyIan]

Hmm, is the float sticking in the carb? and gas running into crankcase and out the bottom seal? The bottom seal on mine is shot but I've never had an oil spot appear under the mower.

 

[spackard]

Maybe do one of these numbers on the muffler:
http://www.youtube.com/watch?v=G5BIltFcEH0

I get some black oil-like syrup off 2-strokes that aren't run hard.
I use a MAPP torch on the muffler to burn off the carbon and syrup.

 

[Best F100]

I have two of the "newer" 6 1/2 HP, 2 stroke Lawn Boys (which exhaust out of the side). It is my understanding that you need to do Either one of two things:

1) Install an inline fuel filter and shut off valve. Do this because you probably have gas leaking past your float or needle valves. There is likely a bit of grass or dirt causing it not to seal. On mine, I shut the valve when I am almost done mowing and let the engine starve for fuel.

2) If you choose not to install a shut off valve, mix in some Seafoam or Marvel Mystery Oil into your 2 cycle fuel mixture. Also check to see if you have a clean exhaust port.

Worked for me!