Smell gas in oil.

[Ronnies1965]

I just changed the oil in my 1989 Sea Ray 220 OV. It has the Chevy 350 with Mercruiser outdrive. I bought the boat August of 2012 and it runs great...no problems. I wanted to do a tune up before this season just to know that it has been done. When I drained the oil I noticed it was thin, and I smelled gas in the oil. I have never experienced this before even with a automotive engine. Does anyone have any ideas on this...is it something I should worry about?

 

[Ronnies1965]

Thanks for the input. This engine has a little over 700 hours and runs great. Even though it runs fine I changed the plugs, wires, cap, rotor, ignition sensor, oil and filter just to know myself it had a fresh tune up. I was just curious since I had smelled the gas in the oil that came out when I changed it.

 

[hottoddie]

Could be one of 2 things. Fuel pump diaphram failed allowing gas to travel up the small plastic hose from the top of the fuel pump directly into the carb throat. The fuel pump can also discharge gas directly into the crankcase if diaphram has failed badly enough. Remove the small hose where it enters the front of the carb, if it has fuel in it the fuel pump has failed. Or carb is allowing too much fuel into intake manifold and is causing an overly rich mixture and needs a rebuild.

 

[Ronnies1965]

Thanks, I will check that out.

 

[blueeyeboatr]

a major issue that always get over looked on any tune up
is the replacement of th the PVC positive crankcase valve
easy to replace and cheap it allows the crank case to breath and cause
many mior issues if left un checked

 

[bjboater]

I was on the water and my oil pressure went way low. Shut down engine and checked the oil. I was over 2 quarts too full and smelled gassy. The fuel pump diaphram had failed and I was getting a steady stream of fuel into carb.