1/2 pint of oil for each gallon of gas, or 16 to 1. This is also true of most OMC engines from the 40’s and 50’s. My 1955 Johnson 5.5 takes a 16:1 per the cowling instructions, and I would think that this would also be true of the ’57. Running a lean oil mixture will cause more damage to the motor than the lack of smoke will benefit.
"Outboards seem to multiply exponentially..........I find that for every finished project, there are two more waiting to be completed."
