FS1 forum

"Torque Induction"
The mechanical revolution came with the RD ("Race Developed")models of 1973, available in 125, 200, 250, and 350cc displacements. All shared the same style and an innovation that would become widely developed: automatic intake valves(but still using ports controlled by the piston skirt)that inspired the mysterious "Torque Induction" motif on the the side panels.This technology, which involved a total of seven intake and exhaust ports, was mostly a matter of publicity but was, however, always used on the 250 and 350 catalogue racers. The RD200 developed more power below 4000 rpm, and apart from the cylinder heads, the engine was new (though the crankcase joint was still verticle). The model was made until 1980 with annual updates: new, angular lines in 1978 and alloy wheels in 1979. It was one of the last bikes in Japan to be fitted with a front disc brake. That was in 1975, although it was only available in 1976 in some export markets.