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Hoffer

Lower unit question for the experts

6 posts in this topic

Ok, so last year before storage - I changed the lower unit oil and did the fogging etc...

I stored the engine in the upright position with the holder in place.

I just took the boat out of storage and it was very dirty and dusty. I brought it to the hand car washer and washed it all down - inlcuding spraying alot of water around the engine area.

The I brought it home and put it in the garage and lowered the engine down for the first time.

Quite a bit of water leaked out - I imagine from the wash. However, in the water there was a pretty mottled amount of oil as it collected on the garage floor. I also noticed a little heavier oil - not so much water - but more oil from the area right around the bottom point of the skeg. The water and the mottled oil seem to come from right inside the propellar area - right on the back where it is round just below the washer that holds the prop in.

So....is this anything to be concerned about?? I am thinking the water must have come from the wash - but I wasnt expecting to see any oil coming out with it. I do know that about half way up the motor on the back side there are these vents. I think alot of water got into those vents during the wash. maybe it then trickled down and picked up some oil?

So...any advice or comments is greatly appreciated!!

(I should add its a 2003 mercury 75 HP. Non 4 stroke.

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The oil is the fogging oil. It couldn't drain out the exhaust since you had the motor tilted up.

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I guess that makes sense - but didnt think you would see that much oil from just spraying some fogging stuff....

and what about the oil that was dripping by the skeg?? where does that come from?

I am just wondering if there was a lower unit issue...but when I changed it - there wasnt any water in it - and I filled it right back up with new lower unit oil- so I wouldnt think there would have been an issue?

It just kind of surprised me.

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I'd have to agree with Dave. However, if you need to be re-assured your lower unit isn't leaking you can always do a quick air test and find out for sure.

Hook a REGULATED air line to your lower unit. Slowly add air until you hit about 8 pounds or so. (Some lower unit tests may be at higher pressure but I figure if it holds at 8 pounds it will hold at 15 pounds.) Shut the air valve feeding the lower unit. Then go away and have a sammich and a beer. Come back later and if it's still holding 8 pounds, you arn't leaking. If you still question weather it's good you can walk away for the night. Come back the next morning and if it's at 8 pounds, it's not a leaker.

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I guess that makes sense - but didnt think you would see that much oil from just spraying some fogging stuff....and what about the oil that was dripping by the skeg?? where does that come from?

Mine does this every year after fogging; comes out the exhaust, out the prop and travels down and back down off the skeg. Check you lower end fluid if you're not sure.

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Hey guys - thanks for the input. I like the air regulator idea - but dont have anything like that at home...

I will try to run it later this week and am hopeful things willbe just fine. Its just good to get some reasurance - and to know that others have this same thing happen....

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