The Yamaha YZF-R6 is a Yamaha 600 class sport bike motorcycle, first introduced in 1999, updated in 2001, 2003, 2006, 2008, 2017, and revised in the years in between. The YZF-R6 was introduced in 1999 as the super sport version of YZF-R1 super bike, and as a companion to the more street-oriented YZF600R sport bike which continued to be sold alongside the R6. The motorcycle featured Yamaha's completely new engine design capable of producing over 108 hp (81 kW) while stationary. The R6 was the world's first 600cc production four-stroke motorcycle producing over 100 hp (75 kW) in stock form. The YZF-R6 has been revised several times since its introduction. Starting with the 2003 model, when the R6 became fuel-injected.