ROK is a 125cc single-cylinder 2 stroke engine by Vortex, with reed valve admission in the crankcase. It is mixture-lubricated and liquid-cooled with integrated water pump. It has got a self-generating digital ignition and an integrated electric starter, which the battery is dedicated to. It is provided with a balancer shaft, which reduces the vibrations. A centrifugal dry clutch makes it possible to keep the engine on even when the kart is still.
