When they was new: 100:1 but i run my motor on 50:1 and it works well!
24:1
A 25hp Evinrude, 1972 year model, requires a 50:1 fuel, to 2 cycle oil, ratio. One pint of 2 cycle oil, to six gallons of fuel, is just a bit richer than 50:1, and a good mix.
25hp
freeze plug on top of engine.
Around 150 to 200
An Evinrude 25hp outboard, 1985 year model, requires a 50:1 fuel, to 2 cycle oil ratio. This is roughly one pint of 2 cycle oil, to six gallons of fuel.
50:1
1972 25hp
used points 0.020 new points 0.022
Model number E25TELCSA, is a tiller electric start, 20" shaft, 1980 year model, 25hp Evinrude outboard.
I use the QL77JC4 Champion plugs with a 0.030in gap.