02 Merc 90 oil leak

[Carolinafrank]

I've got an 02 Merc 2-stroke self oiler. Oil is leaking from somewhere and collecting in the boat well, especially when the motor is tilted over for trailering. I've taken it to two boat dealerships and got no satisfaction. Keep the level low, and don't think it's leaking out the top of the jug. Still leaks as much as ever. I really can't tell where its coming from. Has anybody else had this problem? The self-oiler seems to work fine. The leaks just aggravating.

 

[Bondo]

Re: 02 Merc 90 oil leak

Ayuh,... As with All leaks,....
The Only way to find them is to LOOK....

Take some engine cleaner,+ Clean it up real good,...
Then do whatever it takes for it to Leak, all the while watching for Where it's coming from...
When you find oil,.. Start working your way Up, til there's no more oil....
Usually the leak is at the upper most point....

 

[Faztbullet]

Re: 02 Merc 90 oil leak

The 75/80/90 was bad about this and leaked in 3 places:
1) Where oil level switch mounts in tank,the screw that retains it in tank
2) Vent on top of tank (#19299A1)
3) Gasket under snap cover (#27-8220612)

 

[mikeneal]

Re: 02 Merc 90 oil leak

I have a 1999 90HP merc and the oil tank neck was warped from previous owner over tightening the cap. Just gotta clean it up and trim it up with cowl off and look around.

 

[blackbox]

Re: 02 Merc 90 oil leak

the best way to repair the leak is to replace the oil tank and cap. also do not forget the little green air chk. valve and black cap.

 

[BEPPEQ]

Re: 02 Merc 90 oil leak

I'm not a mechanic, but am having the same problem. I too brought it into 2 mechanics and I got responses from: Its probably oil leaking from your carbs and "Maybe you spilled oil while filling the tank up".

So as suggested above I cleaned the crap out of the engine base and put white paper towel to see were it was leaking from. Well I found it, it was leaking from the oil injector. Now i just have to figure out how too fix it!

So give it a look, it just may be the same!

Bep

 

[jpetker]

Re: 02 Merc 90 oil leak

My oil cap leaks when the motor is tilted up and into the trailer position. This seems to be a design flaw by mercury as my dad has a 2001 120 HP with the same problem. Does any one else have a fix besides replacing the entire tank and cap? Does merc have a redisgned cap that fixes the problem? It is too the point where I will only fill my oil tank half way to keep from having oil every where when the boat is on the trailer.

 

[jpetker]

Re: 02 Merc 90 oil leak

any suggestions?