The Rotax VME is a reed valve direct drive 100cc kart engine (ICA) from Rotax that succeeded the Rotax VMD in 1997. It was the last air cooled Rotax 100cc direct drive reed valve engine. Since then, Rotax have shifted focus towards the Rotax FR125 Max TaG engine and discontinued their 100cc line. An attempt at a last liquid cooled 100cc was done in 1999 with the Rotax VMF but these engines never gained popularity.
The Rotax VME was known to suffer connection rod breakage at high rpm somewhat more often than similar engines of the competition, hence oftentimes it was run with an IAME conrod (not always legal). Apart from this, the Rotax VME is widely regarded one of the best ever air cooled ICA engines. These engines use a right hand side ignition and a closed crankcase half on the left. This construction uses an engine sprocket that is locked against the ignition rotor. These sprockets are difficult to source, but can possibly be machined from standard sprockets.