All four stroke motors use straight gasoline or benzin. Only 2-stroke engines use a gas (benzin) + oil mix. Even some later model 2-stroke engines run straight gasoline and have a pump that mixes the oil with the gasoline. Most 2-strokes built after the mid-70's have the pump. You can easily by examination of the throttle cable. If it's equipped with a pump, the throttle cable will split from one cable on down to two cables where it enters the engine. Read your owner's manual.