ENGINE OIL CASTOR KART 100 ROCK OIL 1LRock Oil Castor Kart 100. Air cooled 2 stroke Kart engines present a unique and difficult challenge. The difficulties are caused by the high revs up to 20,000 rpm causing extreme inertia loads on the bearings and a mean piston speed that without complete lubrication would create intense temperatures leading to an oil breakdown and eventual seizure. Castor Kart 100 contains a high proportion of synthetics. Benefits: Reduced carbon deposits, resulting