50:1
The required fuel/oil ratio for the 98 model, 25 hp Mercury outboard is 50:1. This is roughly one pint of 2 cycle oil, to six gallons of fuel.
An 1985 model, 25 hp Mercury outboard requires a 50:1 fuel, to 2 cycle oil ratio.
40:1 ratio
Mine is a 2000 model and it has an NGK R BPR7HS10
50:1 is what I use
The 1981 model 9.8 hp Mercury outboard requires a 50:1 ratio, this is roughly 1 pint of 2 cycle oil, to 6 gallons of fuel.
The 1973 model, 7.5 hp Mercury outboard requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
The 1978 model, 115 hp Mercury outboard requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
The 1995 model, 25 hp Mercury outboard requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
A 9.9 hp Mercury outboard, serial number OB235459 is a 1988 model.
A 9.9hp Mercury outboard, serial number OB120743, is a 1987 year model.
A 35hp Mercury outboard, serial number A184641, 1985 year model.