What is the gas-oil mixture for a 650 Mercury outboard engine?

6 ounces of two-cycle oil for every 1 gallon of regulargasoline. 12 ounces per 2 gallons, 30 ounces per 5 gallons, etc. Too much oil for cause the engine to smoke. Do not use premium gasoline. Never use any gasoline additives containing a lead substitute. The old outboards were designed to run on "white gas (unleaded). Always use a gas stabilizer added to the oil/gas mix for times when motor won't be used for a while. Keeps the gas from "going bad" and gumming up the fuel system. STA-BIL is a popular brand and sold everywhere.