Fuer die History-Freunde folgt hier ein netter Link:
Few motorcycles have dominated a period of racing in the ultra-competitive arena of 500cc Grand Prix (now MotoGP) like the Yamaha YZR500 of the late Eighties and early Nineties.
The V4 two-stroke machine took Wayne Rainey to three World Championships in 1990, 1991 and 1992 as Yamaha dominated premier class racing.
http://www.yamaha-racing.com/history/headline.asp?PressID=760