Mower Engine Got Drenched With Oil

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The oil cap on top of my push mower's 6HP B&S engine "unlocks" with a quarter turn has an attached dipstick. Apparently, the oil cap unscrewed and lifted while mowing under some shrubs. This evidently caused oil to spray out the open fill port, onto the underside of the open dipstick cap, and back down onto the engine. Hot oil drenched the motor, entered the rotating screen, and even pooled a bit on the mower deck. The air filter is covered and didn't get sprayed. I didn't notice the problem until excessive smoke started spewing out the muffler. A bit of smoke rose from the top of the engine as well. I only noticed the loose oil cap after allowing the engine to cool. Luckily, the oil level remained in the dipstick's crosshatched area, as it was slightly overfilled to start. The next day, I wiped down the mower (difficult to clean the rotating screen) and started the engine. Smoke began puffing out the muffler within seconds. Is this a problem, or should I just let it run and spew smoke?
 
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16,675
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NH
Heh, I did the same thing just the other day. I don't think I got the dipstick on properly--it has two tabs to lock down on, and I think I only got one. I'd run it and ignore it. Any oily will just burn off eventually. If worried, run it for a bit in the backyard where no one will see it.
 
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Florida, Cape Coral
I did the same thing with my riding mower and lost about a 1/2 quart all over the engine and inside the cowling. I cleaned up with some oil cleaner and a hose wash. The mower still smoked for a while. Just check the oil level and mow.Remind self to double check the oil fill cap. :)) Ed
 
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texas
You would not believe what the youtube guys have tried to intentionally kill at B&S lawn mower engine. empty oil and run dry. pour shampoo in the oil chamber. sand down the carb, sand in the crank case. SUGAR in the crank case. Yes they run like crap but that don't die. You probably have oil in the carb that is mixing with the gas. it will take a while to burn off but it will eventually. If not, you wont be the only one pushing a smokey lawnmower. To make you feel better, use your art class skills and make a giant cigar to mount to the top of the engine to justify the smoking.
 
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WA
Originally Posted by Slick17601
Run it till she blows!
I haven't seen a B&S 6hp blow, a Tecumseh shoot the rod out of the block yes but not a B&S. For that reason I'd top off the B&S, it takes about 20 oz. from dry to full, & just run it. Till you're too old to cut grass with a push mower.
 
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Originally Posted by danez_yoda
You probably have oil in the carb that is mixing with the gas.
Oil may have entered the carburetor by spilling on top of the engine and the rotating screen?
Originally Posted by jeepman3071
Just wash the engine with a garden hose, it will burn off the rest.
I wiped down the engine exterior, but smoke puffs out the exhaust. Why would that be expected in this scenario?
 
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Originally Posted by Brian123
You probably still have some oil on the outside of the muffler, did you take the plastic cover off the mower?
Yes, I removed the plastic cover, wiped the engine, muffler, etc., but I didn't spray it with water as some recommend. The smoke is actually puffing out the exhaust, which I found alarming.
Originally Posted by Brian123
You probably have oil in the carb that is mixing with the gas.
How may oil have entered the carburetor?
 
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NH
There is a feed for oil vapor to go into the engine. If it looks like the one I have, it can be seen once the air filter is removed, just a port going off to somewhere (never pulled apart an OHV B&S yet). Why it would now be sucking oil is beyond me--I still think it's got oil trapped in the exhaust somehow, like it pooled in there.
 
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Thanks for the info everyone. I'm still not sure why the smoke is actually puffing out the exhaust, rather than just burning off the exterior surfaces. But the consensus seems to be that it's safe to operate, so I guess that's what I'll do.
 
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Houston, Texas
LOL! This happened to me once. Tipped the mower over too far and I guess oil got in the muffler. It smoked white for the first couple minutes. Only takes about 10 seconds for the muffler to get hot enough to burn the oil. It was smoke free for the first 10 seconds and me thinking something was wrong shut it off, did this about 3 times before realizing what happened. And when I say smoke I mean you can't see the neighbors house anymore. lol Took about 5 minutes to clear up.
 
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Originally Posted by motor_oil_madman
...Took about 5 minutes to clear up.
I allowed the engine to run and it did clear up in about 5 minutes. The problem seems to be resolved. Thanks everyone.
 
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