"almost any motor will perform just fine on a 25:1 ratio. Any motor built after around 1965 will run just fine on 50:1 (20 ml oil on 1 Liter or 2.5 ounces of oil for each gallon of gas) mix. For your 2-stroke outboard, be sure and use only 2-cycle outboard oil, with an NMMA (National Marine Manufacturers Association) certified rating of TCW3.. How to mix 2 stroke fuel. Once you've landed on the ratio you need actually do the mixing. Always store, handle and mix outboard engine fuel in a well ventilated space, ideally outdoors and away from any source of ignition of chance of contamination, i.e. not on the ground of some dusty car park!
Most outboard motors require a 50:1 ratio. How to Create the Oil Mix. Pour the correct amount of 2-stroke oil into a clean gas can. Add the correct amount of gasoline. Stir or shake the container to mix the oil and gas. Use the mixture within 30 days or add fuel stabilizer to extend the shelf life. 2-Stroke Oil Mix Calculator. What Octane Is in Mercury 4 Stroke Outboard? The best option for Mercury 4-stroke outboard fuel is going with the 87 octane. This is highly suggested for some other types of outboard motors like Yamaha as well. Likewise, you can also use the octane 87 fuel even if you have the 2-stroke Mercury engine motor.