Two-strokes still going strong among four-stroke pioneers

The sound changed, the mood changed and for a while it seemed that the sport would make a wholesale change. When four-stroke engines punched their way back into motocross at the turn of the century Yamaha were at the forefront with their innovative YZ400F; an iconic motorcycle that Doug Henry achieved distinction with victory in AMA Supercross but also Andrea Bartolini thanks to 500cc World