The ratio is 50:1.
(There are 128 ounces in a gallon so for every gallon of fuel you will used approximately 2.56 ounces of oil. (128 x 6 gal = 768 oz, 768/50 = 15.36) so for 6 gallons of fuel used 1 pint (16 oz) of oil.)
Merc's use a 50:1 mix
The 1979 - 1980 model, 115 hp Mercury outboard, requires a 50:1 ratio. One pint of 2 cycle oil, to six gallons of fuel.
A 115hp Mercury outboard boat motor has a fuel to oil ratio of 50 to 1. This translates to 16 ounces of 2-cycle oil to every 6 gallons of fuel.
40:1 ratio
the ratio is 50:1 3oz per gallon
Mercury outboards prior to 1966 use a 24:1 fuel to oil ratio.
Mercury outboards, 1966 and up, require a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
50:1
The 65 hp Mercury outboard is designed to operate on 87 octane gasoline mixed with 2 cycle oil at a 50:1 ratio. This is roughly one pint of 2 cycle oil, to six gallons of fuel.
The 1977 model, 20 hp Mercury outboard, requires a 50:1 fuel to oil ratio.
A 175hp Mercury outboard requires a 50:1 fuel to oil ratio.
50:1