To further inspire the research and development of four-stroke motocross racing technology, the American Motorcyclist Association (AMA), America's leading motorcycle sport governing body, increased the allowable displacement limit for four-stroke powered machines in the 125 and 250 AMA Supercross and Motocross championships. Due to the low relative power output of a four-stroke engine compared to the then-dominating two-stroke design, the displacement limit of a four-stroke power motocross bike was raised to 250cc in the 125 class and 550cc in the 250 class.