karts use small 2-stroke or 4-stroke engines. 2-stroke kart engines are developed and built by dedicated manufacturers. Comer, IAME (Parilla, Komet), TM, Vortex, Titan, REFO, Yamaha and Rotax are manufacturers of such engines. These can develop from about 4 hp to 7 hp for a single-cylinder 60 cc unit to 90