two-cycle engine [two-stroke engine]

Also referred to as a two-stroke engine, a two cycle engine is an internal combustion engine that requires two rotations or strokes of the piston to complete a revolution. Gasoline is fired by a spark plug, and this forces the piston downward. While the piston completes its first stroke, air and fuel are forced into the crankcase, forcing the piston back up, thus completing the second stroke and the engine revolution. Each revolution of the engine creates a single boost of power. Two-cycle engines are used in small, low-powered tools and vehicles with smaller engines, such as motorbikes or boat engines.