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1994 Mercury 90HP Lower Unit Leak

D

droeders

New member
I just started my engine this past weekend for the first time in two years. I got it started, but the exhaust was smoking heavier than I remember it. Later in the day, I noticed some oil coming out of a port on the lower unit. It had leaked a small puddle on my driveway, so I cleaned it all up to see where the leak was coming from.

The attached pictures show the leak a couple of hours after I had cleaned it up. It's definitely leaking from the port at the top of the lower unit, and maybe in another spot (based on the two drip lines in the second picture).

Anyone have ideas of what might be wrong based on these pictures?

Thanks for any assistance!
-Drew
 

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Fairly common for a 2 stroke to leak oil there .------Especially after running on a hose.-----It may well be 2 stroke oil / fogging oil that leaks there.------Check lower unit for water in the oil.-------Or have lower unit pressure tested to make sure there are no leaks there.
 
Looks to me like un-burnt, residual 2 stroke oil from over-fogging, not gear oil. To be safe, remove the bottom gearcase drain screw to make sure there is only oil in the gearcase, not water. If you find water in the gearcase, (or low gear oil), pressure test the gearcase before you use the outboard. If the gear oil level is OK, use the outboard as you normally would, which should clear the fogging sludge from the exhaust housing.
 
Thanks to both racerone and bilge rat jim for the responses! I'll check the lower unit for water and the gear oil level.

This would be great news if it's only fogging oil or 2 stroke oil.
 
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