GT33 33cc 2-Stroke Gasoline Engine w. SilencerO. S. Engine GT33 2 Stroke Gas Airplane Engine When it comes to gasoline aircraft engines, the GT33 is in a class of its own. It has the muscle to swing larger props, and it stands out for many other reasons, too. The GT33 runs more quietly than comparable engines while exceeding their output, and it starts easily with electronic ignition that accepts many battery types. Once again O. S. has produced a gasoline powerhouse for the serious pilot!