[devrep]

So this is my new old motor. Did some googling around and read that some years they made the blocks out of Mercosil and that those motors should be run at a 40:1 oil ratio. Anything to this and what years would have had Mercosil blocks?

 

[HaMm3r]

Supposedly, blocks with Mercosil had serial numbers G202750 and higher. My 1999 25hp was Mercosil so I'd bet your 2001 is too. Always ran 50:1 in it.

 

[cutrunner]

A higher quality of oil will make more difference than a 10\1 difference in ratio

 

[devrep]

Roger. Thanks.

 

[RunningOnEmpty]

The older blocks used nikasil chrome plating on the bores. The Mercosil blocks started in 1994 If I remember correctly? I've owned both and always mixed the oil at 50:1 without any problems.