Merc 25hp Outboard; milky oil

5outta6

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Joined
Apr 12, 2010
Messages
16
What are the most likely causes for milky oil?

thermostat?


Any info on the cause of milky oil will be greatly appreciated.
 
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5outta6

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Apr 12, 2010
Messages
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Re: Merc 25hp bigfoot; milky oil---thermostat???

Re: Merc 25hp bigfoot; milky oil---thermostat???

bump
 

Buddaorf

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Apr 13, 2010
Messages
12
Re: Merc 25hp Outboard; milky oil

If its Milky oil in your lower unit. Caused by water mixing with your oil. Its most likey a seal that has gone bad. Probably need to do a rebuild of the lower unit. Not too hard just take your time if you plan on doing it your self.
 

5outta6

Cadet
Joined
Apr 12, 2010
Messages
16
Re: Merc 25hp Outboard; milky oil

If its Milky oil in your lower unit. Caused by water mixing with your oil. Its most likey a seal that has gone bad. Probably need to do a rebuild of the lower unit. Not too hard just take your time if you plan on doing it your self.

I should have mentioned the milky oil is in the engine oil ( 4 stroke bigfoot).
Lower unit is ok.
 

oldgradywhite

Petty Officer 1st Class
Joined
Sep 7, 2007
Messages
232
Re: Merc 25hp Outboard; milky oil

These 4 strokes seem to have a problem "making oil" oil levels rise. What I would do is get a spoon full of that oil and put a lighter under see if to boils if it does its water.
 
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