The '88 6HP I have has had a 50:1 mix since it was new and still works fine.
Just use a good quality oil.
The fuel to oil ratio for a 2000 model, 15 hp Yamaha outboard would be 50:1. Roughly 1 pint of 2 cycle oil to 6 gallons of fuel.
The fuel to oil ratio for a 1988 model, 8hp Johnson outboard, would be 50:1, six gallons of fuel, to one pint of two cycle oil.
An 1986 model Yamaha outboard requires a 50:1 ratio, roughly one pint of 2 cycle oil, to six gallons of fuel.
A non oil injected, 1990 model, 2 stroke Yamaha outboard requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
The 1997 model, 6 hp Yamaha outboard, requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
Carborated
The fuel to oil ratio, for a 1988 model Suzuki outboard is 50:1, roughly 1 pint of 2 cycle oil, to six gallons of fuel.
If operating the outboard, without the oil injection system, use a 50:1 ratio. This is roughly one pint of 2 cycle oil, to six gallons of fuel.
The non oil injected model 60 hp Yamaha outboard requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
100:1
The 55 hp model Yamaha requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
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