QuestionQUESTION: Hi, I have an Oil in air filter Problem on a Briggs and Stratton 16hp OHV Engine. Model 28Q777-0668-E1. I bought the TORO LAWN TRACTOR 1644HXL second hand, and when I rode it for the first time it blew a lot of white smoke after a couple of minutes of cutting, so bad I had to turn it off. So I drained the oil at the sump (could not take oil filter off) and refilled it with the proper Briggs and Stratton oil and replaced the air filter with a new one as the old one was covered in oil and needed to be replaced. I also replaced the spark plug as it was very black and oily. I then ran the engine for a while without the air filter on to hopefully get all the oil out from shooting up into the air filter out of the breather, and after about 5 minutes of the engine running in idle (with some throttle) i thought it was about time to try it out, and put the new air filter on and proceeded to cut the lawn.
This time there was no white smoke. Perhaps a little smokey but not much and I managed to mow all the lawn without a problem. When I finished after about 20 minutes, I parked the mower and checked the air filter to see whether oil was still shooting up into it from the breather pipe that goes into the motor. Not a great amount but enough to have liquid oil splattered on the roof of the air filter and covering about a quarter of the inside. Everything else on the mower works fine. Easy to start etc. Cuts great, but I am surprised at the lack of speed. I thought it would go faster but that could just be me not used to it as it is an automatic transmission. The mower has no oil leaks at all that I can see, and there is never any oil drips on the concrete. Please help me as I just want the oil to stop shooting up into the air filter out of the breather pipe which goes into the mowers engine. Thank you.
ANSWER: Did/does the oil smell like gasoline? Sometimes the carburetors leaks allowing gas to enter the engine crankcase thus thinning the oil. This will cause the engine to smoke.
Along with smoking, the valve breather valve can become sticky causing it to malfunction. Follow the breather tube to the valve breather. Remove and clean the valve breather with parts cleaner. Valve breathers are usually very inexpensive...it may be easier to replace the part (696126).
The valve breather should rattle like a baby rattle indicating the valve it not sticking.
Clean or replace the breather, check the oil level and see if there is a gas smell.
Let me know what you find.
Eric
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QUESTION: Hi, I finally got the valve breather off by taking the fly wheel off, and it all looked fine, so i cleaned the valve breather just incase, but I forgot to mention when the motor is running exhaust comes out of the oil filler tube if I lift the lid off. Does this mean petrol is getting into the oil? Also, when i looked down the valve breather hole, after i took the valve cover and valve off, I could see liquid of some kind. I presume this is oil and it is normal to see? Everything was crystal clean in the is area and seemed to work fine, so i don't think it's the problem. Thanks olly.
AnswerIf you have a vacuum gauge you can check to see if positive pressure exists in the engine. No one, that I know of, sell adapters for small engines so we make our own.
Purchase rubber cork from your local hardware store. The cork should fit snuggly in the dipstick tube. Drill, melt or use a rotary tool to bore a hole in the center of the rubber cork large enough to accept an adapter to connect your vacuum gauge tool. We use metal fuel line nipples. Silicone the nipple to ensure it doesn't leak.
Once made, insert the rubber cork and vacuum gauge in the dipstick tube and start the engine. You should have vacuum and very little positive pressure.
Let me know if this makes sense.
Eric
