Water in the Lower Unit

[Daze Off]

Just winterized the boat motor 75hp Merc and found that water had infiltrated the lower unit at some point - any idea what kind of repairs are required and how much they might set me back? Never had this happen to me before....

Daze Off

[mtreno]

ouch - there is only one cheap long shot way i know of out of this one. bad seal on the plug - other than that your talking about a new lower unit.

[marine_man]

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other than that your talking about a new lower unit.

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Not neccesarily... it could be as simple as the prop shaft seal got some fishing line wrapped around it, cutting the seal. It'll require replacing, but way cheaper than replacing the entire lower unit.

I'd say replace the lower unit oil to cover you until spring for sure... if you're in the mood and a little handy take the lower unit off and into the dealer and have them take a look at it. They'll pressurize the lower unit and figure out which seal(s) are leaking.

Double check your plugs, both top and bottom to make sure they've got a gasket on them (and only one).. other than that I'd say it's time for a trip into the dealer.

It can wait till spring since you've replaced the lube, but if you take it in now you won't have to deal with it in spring.

marine_man

[eurolarva]

If you are not up to the task yourself call around to marinas. I had Twin City outboard do mine for 200 bucks about 5 years ago but it had to be done over the winter. Marinas are real slow during the winter so you might get a better deal. Seal kit for that motor is about 30 bucks and a service manual is about 40 dollars. Good Luck

[ChuckN]

Ditto what eurolarva said.

[Daze Off]

Thanks guys - I am not handy with engines at all - it was a big undertaking to winterize it myself this year (with help from neighbor) - always had it done by shop in past so will be taking it to a shop - called the dealer where I bought it who indicated it could be as simple as the prop seal ($150 P&L). So will try that route first and hope for the best.

Weird part is that I thought I saw water emerging from around the sacrificial anti-corrosive plate while we were running the motor with the rabbit ears to fog the top. Did not look too closely as I had no real reason to at that point. I remember thinking it must've been side spray from the ears.

Daze Off

[blgoose]

I had the same problem this year with my 40 hp merc.Its wasnt just a little water more like a cup. No fishing line around the shaft either.I noticed the drain plug and fill plug had no rubber washer.I am hoping this is the problem.Is there supose to be a rubber washer? I know there's one on my 50 hp yamaha.

[Dave]

Make sure the rubber washer isn't just stuck to the lower unit after pulling out the plugs, too.

[Valv]

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Is there suppose to be a rubber washer? I know there's one on my 50 hp yamaha.

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Yes, you ahve to have a washer to seal, as mentioned check if it's stuck in the therad of the hole, if not you've probably found your problem, and remember there are 2 plugs with washer, the drain/fill (bottom) and the overfill (top).

[Rivernut]

Daze, I had the same with my 25 Mer. All it was, was a prop shaft. Get the kit and the repair manual and you're in business. Manual is a good thing to have around. You'll be able to handle it just fine. I should add that it's not a bad idea to pay a dealer to pressure test it first.

[rookie44]

if you run your motor with a broken or off balance prop,the seal can go out from shaft vibration also.

[Daze Off]

Excellent suggestion! Thanks!

Daze Off