Re: mixture of fuel
from oldmercs.com
Q. What is the proper fuel to oil ratio for my old outboard?
A. The currently preferred fuel is the mid grade (89 octane). All post World War II non-racing Mercs (except KB-4's) can operate safely on a 50 to 1 fuel/oil mixture using modern TCW 3 oil. Racing models and the KB-4's should not be run leaner than 25 to 1.