Kohler 20resa blowing oil out muffler

Kohler Home Standby & Commercial generator troubleshooting and repair questions
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KohlerKrap
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I have a 2013 kohler 20resa that started blowing smoke and oil out of the muffler. Last oil change was done in December. There was also oil in the air bow but none inside the enclosure. Any ideas
Chris
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Sounds like someone way overfilled the oil!
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KohlerKrap
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I drained the oil yesterd and it was about 3/4 of a quart over,im thinking since it was cold out when i did my oil change that if it was residual and i just added to that and didnt get a good read on dipstick why would it run 14x and then blow. Local guy mentioned sabotage but i didnt even think that route. Any how i did a compression test with plugs out and readings were 188 & 195 so then i removed heads and there was oil puddles on pistons and push rod chamber.
Just puzzled since its run all this time and were back home now and then this happens, just glad i was doing yard work at the time to shut it down right away,it was smoking like you were in the clouds.
Any help would be greatly appreciated.
Thanks
Birken Vogt
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Sounds like you took the heads off when it could have been fixed by just draining to the proper level and letting it run long enough to blow out the oil.

The only way for oil to get on top of the pistons like that is to carry over from the breather.

I had a 14RESA do the same thing when a customer overfilled it. Took 2 cycles of running because the smoke was tremendous and did not want the fire department to show up, oil blowing out the muffler, but eventually it cleared right up, never even removed the plugs until months later, and they looked fine then.
KohlerKrap
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I hope thats it just doesn't explain why it would happen months later so im going to get new gaskets and re assemble heads and make sure theres only 2.9 quarts oil.
Appreciate your feed back
Birken Vogt
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Don't put any particular quantity of oil in.

Look at the dipstick and fill it to that.

Just changed oil on one of these today and it only took 2.5 quarts. Usually they take 2.0 on an oil change in my experience. Maybe some does not drain off the bottom. The dipstick is the only standard, not how much the book says "should" go in.
KohlerKrap
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Goid advice, i plan on doing that and next time i set up a generator i'll raise the height of my pan so its easier to drain.
VelvetFoot
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Not a Generac tech, but I once had a brand new snowblower delivered to my house that was supposed to be set up and ready to go. There was no oil on the dipstick. Guy came out. Turns out it had the wrong length dipstick. Snowblower's been working great for years.

Yesterday, I changed the oil in my warmed-up lawn tractor. I put in the 64 oz the B&S V-twin required. Casually checked dipstick: low. Turns out I didn't lock it in. After doing that, perfect.

On my predator generator, log splitter, and (I think???, lol) other similar types, you fill the oil until it comes out of the fill hole. To check, you don't screw in the dipstick/drain plug, you just put in in the hole. Granted, most of these types have low oil cutoffs, but still.

My MINI does not even have a dipstick! It'll give you a warning if it gets low. 107,000 miles so far.

I'd say, become familiar with what the mfr. says for checking the dipstick, warm up the oil, drain well, and put in the measured mfr. requirement of oil. Then check dipstick.
KohlerKrap
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All goid advice and greatly appreciated and imwas just wondering if anyone knows why this didnt happen back right after i did the oil change and it has run for 14 weeks while i was out of town. Why now?
Birken Vogt
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Maybe it was just high enough that the crank was barely touching it and took time to introduce air to make it into whipped cream? And it only ran short cycles until you had a real outage and it had enough time to get out of hand?

Maybe it was down low but as it got hotter it expanded to the point the crank was whipping it?

Maybe the breather valve where the hose originates has had some kind of failure?

Very strange to be sure.
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