ROK is a 125cc single-cylinder 2 stroke engine by Vortex, with reed valve admission in the crankcase.
It is mixturelubricated and liquid-cooled with integrated water pump.
It has got a 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.