Johnson and Evinrude outboards use the engine model number, rather than the serial number, to determine the year model of the engine.
Mine is same year and HP and it is 50:1
A Johnson outboard engine, model number RDE19M, would be a 1957 year model, 35 hp outboard.
A Johnson outboard, model number J35BALCSM, would be a 1980 model, 35 hp engine.
70 kg
A 90 hp Johnson outboard, model number J90PLEEB, would be a 1999 year model.
The fuel to oil ratio for a 1977 model, 35 hp Johnson, is 50:1. This is roughly, one pint of 2 cycle oil, to six gallons of fuel.
Your 15 hp Johnson is a 1982 year model.
A 3 hp Johnson outboard, model number J3BRESR would be a 1990 year model.
A 25 hp Johnson, model CJ25RWK, is a 1989 year model, commercial outboard.
A 35 hp Mercury outboard, serial number OC132923, would be a 1990 year model.
A 35 hp Mercury outboard, serial number OB201519, would be a 1987 year model.
The Johnson outboard part with serial number VJ30ELETA was a 30HP model. This model was manufactured in 1993. The 35HP model serial numbers are J35RETA and J35RLETA.