Honda's first attempt at a 750 dirt tracker. Started out as a CX500 road bike, and with a large amount of work the engine was totally reconfigured, turned 90 degrees, converted to chain drive and bored and stroked. The motor was installed in a proper dirt track frame but all that work resulted in only one win. Apparently five were built. Still, the stage was set for the next project, the much more successful RS750.