Be aware that they are typically not run in TaG classes. As far as I know, this motor is not approved by WKA, IKF, SKUSA or TAG USA. As a result, you may find limited opportunity to run it.
Fall Winter 2014 Ocala Gran Prix opened Rok Classes for all ages so new Rokker owners could go race but its not a TAG approved engine yet . We join same race together (Rotax/TAG/ROK) but different classes. Rok Master Weight Limit Rok Cup Usa: 380Lbs , Rok Master @ OGP : 405lbs