Jump to content

Have some oil leaking from what i believe is drain holes on my 90 HP Mercury.


Recommended Posts

Ok maybe someone can explain to me what is going on here. Im going to post some pictures up to show this a little better. Small puddles of what looks like 2-stroke oil is coming out of little port hole above the lower unit oil fill plugs, and also leaking out of little hole behind the water intake on lower part of motor. No clue whats going on here.Its not a ton of oil. about half dollar size came out of hole back by the prop, and about twice that amount came out of hole by the lower unit oil check plug.

 

I have one more picture but im just having a problem loading it. Its the picture of where oil is leaking from that little hole back by the prop. Please any help here and an understanding of whats actually going on would be great. Thanks a bunch

post-155404-0-00738400-1403804290_thumb.jpg

post-155404-0-04953800-1403804406_thumb.jpg

Link to comment
Share on other sites

That is fine. No problem. Here's why.

Often ,not all the oil mixed into your fuel gets burnt in the cylinders. This happens specially at low RPM. This oil goes out the exhaust into the water. Oil is lighter than water. The exhaust housing in your lower unit is usually mostly under water and water is inside of it. At low RPM the exhaust gas does not have enough pressure to blow the water and crud all out and some stays floating on top of the water inside the exhaust housing. When you pull the boat, the oil and crud sticks to the inside of the housing and slowly comes down and seeps out through a vent hole.

That is the oil you see seeping out.

It is always a good idea to check you lower unit oil to see if it is at the right level or mixed in with water

Edited by rolmops
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...