About: 2si 690

The 2si 690 is a family of in-line three cylinder, liquid-cooled, two-stroke, dual ignition, aircraft engines that were designed for ultralight aircraft. The basic engine was originally designed and produced by JLO-Motorenwerke of Germany and was later acquired by the AMW Cuyuna Engine Company of Beaufort, South Carolina and marketed under the Cuyuna brand name. Later the engine was marketed by Cuyuna under the Two Stroke International (2si) brand. Cuyuna no longer markets engines for aircraft use although the 690 is still in production as an industrial and marine engine.