[leawilson]

I have a 1996 6x4 Gasoline powered Gator. The engine is a Kawasaki. Recently we started to feel it being underpowered, and lacking the impulsion it once had. Then it started blowing blue smoke. We did a compression check, and that seems fine. Changed the spark plugs. We then checked the motor oil, and smelled gasoline in it. We are changing the oil, but wondering... under what conditions could gasoline actually get into the engine oil? Any ideas? Any help would be greatly appreciated!

 

[xcopterdoc]

There can be several reasons for gas in the oil.
Could be carb issue. Engine starts running rich, all of the fuel isnt burned and it ends up in the oil. Another carb issue could be a leaking needle or needle seay. Allowing gas to get into the cylinder after shutdown and leak past the rings into the oil.
The most likely way is what is called "short tripping". Short trips here and there, never really getting the engine up to operating temp for any period of time. All internal combustion engines will get gas in the oil. But running them at temp for a while will allow the fuel to evaporate out. Also over time, plugs get old and dont fire as good as they once did. Theres some more unburnt gas getting into the oil.
If you notice it being way over full on the dipstick, its likely a carb problem. A slow increase in oil level or just the smell of gas in oil, I would vote for short tripping.
On a closing note, make sure that thermostat is operating properly. One that is stuck open will never let the engine fully warm up. If you havent ever changed it I would do so, along with a coolant change.

 

[leawilson]

Thank you very much! The short tripping could be it. The Gator is used on a farm for cleaning stalls, so often time the engine gets started and then they move it forward and turn it off again. I'm wondering if that is contributing to the problem. I really appreciate your help!

 

[vanderrt]

Xcopterdoc doesn't it sound more like rings mainly because of the loss of power although I know that gas washing down the cylinders can cause blow-by and loss of power also.

 

[marcust90]

it could be washed out rings but there has to be a reason Y the rings washed out vanderrt so there is were xcopterdoc is coming from but there is a very good possiblity that is the main problem.

 

[catchtwine]

This seems to be a problem and I came across the answer from Deere. They basically state that this is a normal result for "short tripping" short runs where the engine doesn't reach operating temp. The fuel doesn't fully burn it combines with condensation and finds it way to the crank case. If the engine would reach operating temp for a significant amount of time, the condensation would steam and the fuel would vapor both going back into the carb through the case vent to be re burned. I have put my 20yrs as a mechanic to the test on this. If the carb had adjustments this problem could be adjusted out. I am toying with idea of removing the cooling fan (air cooled). Short tripping is the nature of the usage we experience and changing the oil every 10hrs is ridiculous. Its about the only way I can think of hitting operating temp faster. I don't think I will have to worry about overheating to much in "my conditions".