1994 Mercury 90hp leaks oil

[starcraftlegasea]

I am looking at purchasing a 1994 90hp mercury outboard. The only problem it seems to have is that when the motor is trimmed all the way up it leaks oil out of the powerhead. The guy I'm buying it off of says that he thinks it is coming out of the oil tank inside of the engine but he is sure. Does this sound like a big problem? Should I simply mix my gas and oil together and not worry about using the oil injection system?

 

[starcraftlegasea]

Re: 1994 Mercury 90hp leaks oil

Should I forget about buying the engine if it has this problem?

 

[P51D]

Re: 1994 Mercury 90hp leaks oil

It may be leaking from the cap for the engine mounted reservoir. The cap can crack and leak. With the cap screwed on moderately tight, look and feel for a horizontal crack towards the top of the cap. When mine cracked, it was pretty obvious where the leak was. New cap is about $40 - $45.

There is also a recent post about oil lines getting brittle and cracking, which can lead to loss of lubrication and a blown engine.

I would first try to determine where the leak is.

 

[Texasmark]

Re: 1994 Mercury 90hp leaks oil

I bought a used '02 90. Had the same problem. Investigation revealed that the seal on the oil cap was leaking because the previous owner had stripped the threads on the oil reservoir cap by being careless when replacing it.

A new seal and cap solved the problem and they were not very expensive from my local Merc dealer.

Mark