My motor says 100 to 1 right next to the fuel connection....
I have a 1988 25 hp LS Evinrude pull start and I weighed it at 123 lbs.Retired auto tech
The 25 hp Evinrude outboard has been designed to run a 50:1 ratio, for earlier models, and 100:1 for late model engines. Pre 1965 models run a 24:1 ratio.
The late model 25 Evinrude suggests operating on a 100:1 ratio. I prefer the old time tested 50:1 ratio, one pint of two cycle oil, to six gallons of fuel. I have never seen an outboard powerhead failure, due to running a 50:1 mix.
.G Argo Boat Company http://www.argoboat-ny.com
The 1979 model, 25 hp Evinrude requires a 50:1 ratio, one pint of 2 cycle oil, to six gallons of fuel.
50 to 1
For the 1990 model, 25 hp Evinrude outboard, use a 50:1 ratio, roughly 1 pint of 2 cycle oil, to six gallons of fuel.
Yes, a 25 to 1 oil mix is stronger than a 50 to 1 mix because it contains a higher ratio of oil to fuel. In a 25 to 1 mix, there is 25 parts fuel for every 1 part oil, while in a 50 to 1 mix, there are 50 parts fuel for every 1 part oil. This means that the 25 to 1 mix has a greater concentration of oil, providing more lubrication, which can be beneficial for certain two-stroke engines, especially under heavy load or high-performance conditions.
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.
A 25 hp Evinrude, model number E25RCNB, would be a 1982 year model.
25
Look up and see answer entered for "25 hp Evinrude". It is the same.