The RS125 Came with 2 types of engine from 1996 to 1998 Aprilia fitted the Rotax 123 type engine, and from 1998 to present day they fit the Rotax 122 type engine.. Aprilia RS 125 Con Rod Kit Moto RRT Con Rod Kit To Fit The Aprilia RS 125 All Years 1994-2013 Both The Rotax 122 Type Engine And The Rotax 123 Type Engine..