The 1984 model, 9.9 hp Mercury outboard requires a 50:1 ratio. This is one pint of 2 cycle oil, to six gallons of fuel.
1984.
A 25 hp Mercury outboard, serial number 6459040, is a 1984 year model.
50:1 Oil to gas ratio
How do I remove the lower unit from my 1984 50 hp. Mercury outboard motor?
A 9.8 hp Mercury outboard, serial number 6518104, would be a 1984 year model.
50:1 ratio 16 oz 2 stroke marine motor oil to every 6 gallons of gasoline this is most common I use this mix ratio in my 80 hp mercury spitfire
I have a 1984 90hp Mercury outboard and the fuel mixture is 50:1 which is one pint of 2 cycle motor oil for every 6 gallons of gas.
A 115 hp Mercury, serial number 6580904, is a 1984 year model.
A 75 hp Mercury outboard, serial number 6559291, is a 1984 year model.
If not using the oil injection system, a 150hp Mercury outboard would require a 50:1 ratio. This is roughly, one pint of 2 cycle oil, to six gallons of fuel.
The dry weight of a 1984 model Mercury outboard is 186 lbs.