Kevin Schwantz won the 1993 world championship in a season marred by the tragic end to his rival Wayne Rainey's career. Schwantz started the season strong with four wins by the midpoint of the season. With three races remaining, Rainey had battled back to take the championship points lead while Schwantz nursed a wrist injury. At the Italian Grand Prix, Rainey had just taken the lead and was pulling away when he fell. He suffered serious spinal injuries and would never walk again. Rainey's accident marked the end of an era of American domination in Grand Prix racing.
Newcomers Daryl Beattie and Alex Barros took their first wins (Barros after twice crashing out of the lead) while Mick Doohan struggled to recover from his serious leg injuries.Freddie Spencer made one more comeback attempt but crashed in two of the first three rounds.Honda entered factory test rider Shinichi Itoh on a third bike with development parts, rumored to include electronic fuel injection, as he was noticeably faster in a straight line that the other Honda riders. When Itoh broke the 200 mph barrier at Hockenheim, it gave credence to these rumors. Officially, all three bikes gained the injection system at the same time