Small gas or oil leak?

[artlawton]

Hello. I have a 2006 Merc 4-stroke 75hp outboard. I keep my boat on a trailer. When I launch, I notice a small slick around the motor. See photo. I know it's hard to see, but you may be able to see this "slick" in the water. This morning I changed my lower unit oil and did not see a sign of water in it. When the boat is on the trailer, I cannot find anything leaking. I don't see any change in my engine oil level, but according to my dip stick, there is more oil in the engine than there is supposed to be. Any suggestions would be appreciated. Thank you!...

 

[alldodge]

Wish I could advise but I do see the oil slick and if you are gaining oil you have water getting into the crank case. Oil floats to the top so you could have an inch of water on the bottom, and when you pull the dip stick out you only see oil. Hope a 4 stroke outboard dude shows up, but you do have water getting in the engine and I would suggest not running it until you can figure it out

 

[roscoe]

You could very well be "making oil."

A situation that some 4 stroke motors have, especially if used at slower speeds for extended periods of time, or in cold water conditions.


Basically, gasoline getting into the crankcase, and adding gas to your oil.
Seems to happen more if motor was not broken in properly.

As for the oil sheen on the water, could be a small amount of oil getting into your exhaust.


This could be normal for your motor. Or, you could have a worn or damaged piston ring, which would explain the gas getting into the oil, and the oil going out with your exhaust.

If it really bothers you, do a compression test, and a leak down test, on each cylinder.

Any idea how many hours are on this motor?



http://continuouswave.com/ubb/Forum4/HTML/001503.html


http://www.walleyecentral.com/forums/showthread.php?t=188971