Re: Fuel:Oil Ratios

[Leon]

quote Mumbles:

I have he same list Tubs posted in my ’80 Parts Guide but I strongly disagree with a few things on it. First, I would never run an AD or pre ’61 CD motor on anything less than 16:1 because of their rod bearing design. The same goes with the three horse JW-JH series of motors although they will live on 24:1 mix. At least they got the TN right at 16:1 as it needs the extra oil to seal itself.

You might notice that lots of these 50:1 motors from the sixties and seventies have vanished but there’s still lots of motors in use from the fifties and forties. I wonder if it has something to do with the little bit of extra oil added to the mix?

I completely agree here. The little 3 horse needs the 16:1 because there isn’t any needles in it, except the later ones having the top crank bearing on needles.
Oil is the cheapest thing you’ll ever put in an outboard