Small Gas Engine Question

[Wire Weasel]

I have an old but good Craftsman walk-behind with a 3hp Tecumseh engine. Had since new, always well maintained. Always full and clean oil. Still cranks right up and runs good as new. Burns no oil - no smoke ever. Issue recently is, when running it pushes a small amount of oil out of the breather. Clean air filter. What is causing the oil to come out?

 

[FlatlandBusa]

A few things could cause this. Over filled with oil is the easiest to fix. See in the breather is supposed to have an open cell foam oil separator in it, the foam may have dissolved. Or the rings could be worn allowing combustion pressure into the crankcase.

 

[Eldorado828]

Does that engine have a reed valve? I'm not familiar with the tecumseh but have replaced many reed valves on briggs. Surely that engine has a similar method of keeping the oil out of the breather.

 

[Wire Weasel]

If it's rings or reed value, I have no way to check or fix. I'm not tearing the engine down. - It's not overfill on oil .... has a dipstick. - It's not gushing large amounts. Might push out 1 ounce in a 20 minute run. The mower is kindof a backup. I only use it in a small area and mostly just to keep it operating. Like I say it runs great so as long as it doesn't doesn't get much worse I can live with what it's doing - I will take the cover off the breather and check the foam pad. Thanks!

 

[Shadetree Mechanic]

One easy thing to do that might help, pull the plug and put some seafoam cleaner or marvel mystery oil in the cylinder, and let it sit for a few days. If the rings are sticking because they are coked and carboned up, this will help free them up. Put some in the oil too, to help keep the valves from sticking. This helps old cars too.

I still have my grandfather's Snapper walk behind from the early 70s. Sadly, I can't get parts for the recoil starter anymore.

 

[unit_399]

I still have my grandfather's Snapper walk behind from the early 70s. Sadly, I can't get parts for the recoil starter anymore.

If it's not a complicated part, maybe you can have someone 3D print it. I've had several NLA car parts made this way.

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