The 1975 model, 70 hp Chrysler requires a 50:1 ratio. This is 3 oz. of 2 cycle oil, to each gallon of fuel.
50 to1
50:1
All Chrysler motors built after 1969 use a 50:1 mixture
Chrysler outboards produced after 1966 require a 50:1 fuel to oil mix.
50:1
40:1
50:1
The 1975 model, 45 hp Chrysler outboard, requires a 50:1 ratio, roughly one pint of 2 cycle oil, to six gallons of fuel.
From 1975 when I owned a mac 3 it was fine at 25 to 1 regards
The 1975 model, 9.9 hp Johnson outboard requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
50:1 they say i got the same engine as you. 50:1 does the trick.