0skunkbaitBest Answer 11 years ago Ok, a lot of mopeds and other two stroke machines have a "mixer" for the fuel and 2-stroke oil. They usually have a seperate reservoir for 2-stroke oil, and a drip/injection/vacuum operated way to meter out the oil in the correct ratio. If the mixer is working, it's best just to use it. Put the fuel in the fuel tank, and the 2-stroke oil in the 2-stroke oil reservoir. But if the mixer has failed, you can premix the fuel and oil, like you would for a chainsaw, weed-eater, etc. Just measure carefully. You need to find out the correct ratio. Ratios usually run from 20:1 up to 50:1. If in doubt, go with 20:1 as it is safer for the life of your engine. If it's too rich, it'll smoke a lot and the plugs may foul. But if it's too lean, you will likely DESTROY your engine.