Fuel in the oil 2005 4 stroke

[Zygmunt]

I have a 2005 Mercury 75 hp 4-Stroke. After last winter I took the boat out a couple times and when i checked the oil i noticed that there was more oil than there should be. I started to worry that there was water in the oil. When i opened the oil drain, i noticed that it wasn't water but fuel in the oil. I took the engine to the dealer and they couldn't find anything wrong with it. They suggested that i change the oil and try to run it. I took the boat out last sunday and used the motor for about 2-3 hours. The next day when i checked the oil, it was about half an inch higher than it was before and i noticed the smell of the fuel in it.

Any idea what could be causing this?

P.S. I bought the engine brand new, broke it in properly, and it has about 30-40 hours on it.

I'd appreciate any ideas that could help me solve this problem.

 

[JB]

Re: Fuel in the oil 2005 4 stroke

Howdy,

Welcome to iboats.

Check out the article on 4 strokes "making oil" in the Engine FAQs.

 

[Zygmunt]

Re: Fuel in the oil 2005 4 stroke

Thanks for the advice JB, but that thread mostly deals with water in the oil, and I know what causes that. But my problem isn't water in the oil, it's fuel. When I drain the oil, some fuel comes out first, and then fuel mixed with oil. I can smell a strong scent of fuel. Last fall I had water in the oil from condensation, and I know what that looks like. This is a different problem altogether.

 

[wildbill59]

Re: Fuel in the oil 2005 4 stroke

Take a serious look at the fuel pump diaphragms