Re: Mark 25 fuel oil mix

[billw]

quote Cheetahgod:

There is a yellow oil in my mark 25 lower unit. Is it supposed to have grease instead ?

Like Dave said, it was supposed to have a thin grease, but NOT regular automotive grease. 99% of old Mercury lower units out there today don’t have the seals or shaft surfaces capable of holding in oil. Consider yourself gifted to find one that WILL hold gear oil. I reseal all mine and use 90W oil all the time. It works fine and is very easy to change fresh after each use, which in my case is once about every eight years. If you choose to keep using oil, just remember to check it and change it after each use. (You should be doing that with grease, too, anyway, given the history of old Mercury lower units.)

Long live American manufacturing!