Re: '68 Johnsonn FD-22M 20Hp Proper Fuel/Oil Mix???
OMC made the change on that in 1964, Bob. All pre-1964 outboards were to use 24:1 and all 1964 and later outboards were to use 50:1.
In the last 48 years we have discovered that the outboards that still used "friction" bearings should stick with 24:1 and those that use "frictionless" (ball and needle) bearings can do with 50:1.
I believe that your FD-22M is okay with 50:1.
However, remember the rule. More oil than needed is pretty much harmless. Less oil is usually fatal.
