This 1997 Yamaha YZM400F racebike campaigned in AMA Supercross and motocross by Hall of Fame racer Doug Henry.Today, four-strokes dominate professional motocross, but a little more than a decade ago, two-strokes were the only motorcycles that had ever carried a rider to a podium in an AMA national. Seeking to explore the possibilities of four-strokes, Yamaha built this 400cc prototype and asked Henry to race it in the 1997 Supercross and motocross seasons.
In the final round of the Supercross season in Las Vegas, Henry pulled away from the start and won the race. The change didn’t happen overnight, but that victory (and this motorcycle) marked the beginning of the four-stroke era in motocross.