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kevfish1

Motor grease milky

15 posts in this topic

OK, I changed the oil in the lower unit of my 75 HP Mercury outboard today and the oil was Milky colored. I had not changed the oil for app. 2 years. Is this normal? Or is there a problem? What would be the possible problems if this is not normal. I know you are suppose to change this every fall incase there is some water in there

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OK, I changed the oil in the lower unit of my 75 HP Mercury outboard today and the oil was Milky colored. I had not changed the oil for app. 2 years. Is this normal? Or is there a problem? What would be the possible problems if this is not normal. I know you are suppose to change this every fall incase there is some water in there

I'm guessing you got some water in there.

The problem is that if you leave water in the lower unit and your boat is not stored in a heated garage it could freeze and crack your lower unit.

I'm not a motor expert but i picked one up many years ago from someone that had that same problem and i needed a new lower unit

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I'll second that, I don't know much overall about motors but if the lower unit lube is milky you got water in there. Drain and replace. Like tackle junkie said if there is water in there and it freezes you are looking for a new lower unit.

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There are a couple of ways that water can get in.

When you change the oil, get new rings for the

two bolts too. They don't last forever

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Sounds like you have a seal going out. If you leave your boat in the water or sitting on a lift with the lower unit in the water all summer, I would get it replaced if the gear oil is milky. Milky means water got in! frown

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I should add that the washer on the plug was gone. I must have not put it on the last time that I changed the lube. The bolt was tite. Could enough water to make it milky have gotten in because of the washer missing??? Also I went up town to replace the washer and All I could find was rubber O-rings. The original was a flat rubber washer??????

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if you had it on a boat lift all summer with the lower in the water its understandable to have some water in it not having the washer on the plug didnt help... i wouldnt worry about it unless the oil gets white as paper then fix it.. just rember to drain all the oil in the winter and change peridocily in the summer.. both my engines have leaked for 10 years and still run like a top

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It was not white as paper but was more of a brown tinged white. The boat is kept in the garage and used app 6 times a year

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I would install new washers on both fill and vent screws and run it then check it next time when you get back from using it, and make sure you change the fluid in the fall before winter. If it does get milky again take it in and have it repaired while it is still a cheap fix.

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would just using it one time for a few hours be enough to check for water?????

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It depends on how big the leak is, but it would give you an indication.

The risk here is that the water froze over the winter and pushed a seal out. But, if it was missing the washer it's possible that's all it is, and you got lucky.

I would get the correct washer - a marine dealer should have them on hand.

marine_man

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I agree with twostroke 100%. my old johnson was full of water and missing its two washers on the drain screws. I refilled, added the washers and then ran it. no water since.

this is good reason to change it in the fall and check it at least once during the season.

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I would change the oil, replace the fill screw washers and use it a couple of times, then check the oil again. Like the advice above, this time of year a little water in the oil won't ruin anything right away.

If you do this test and it gets milky again, pull the prop and check for fishing line wrapped around under the prop. It can wind up and damage the seal, allowing water to get in. Pretty easy to fix so it should not be very expensive.

DO NOT leave milky oil in the gearcase over the winter. The water will separate out and can crack your gearcase.

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water can also get in through the shift linkage...

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My 4 stroke Merc will collect moisture in the gear oil in the winter if its stored outside for an extended period. Mercury told me that can happen.

I change my oil before winter to make sure no moisture is in there. Again in the spring I pull the plug to check the gear oil again.

Gear oil is cheaper than a cracked lower unit.

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