The Hirth 2704 and 2706 are a family of in-line twin cylinder, two stroke, carburetted aircraft engines, with optional fuel injection, designed for use on ultralight aircraft and especially two seat ultralight trainers, single seat gyrocopters and small homebuilts. It was manufactured by Hirth of Germany. The series is out of production and were replaced by the Hirth 3202 and 3203 in May 2002.