All Monsters of the long first generation, pre-2007, feature Ducati’s desmodromics with either a two-valve air-cooled or a four-valve water-cooled mill. Displacement ranges from the 600cc M600 mini-Monster to the 998cc S4RS Testastretta beast. Fuel injection appeared on the M900ie in 2000, along with a minor styling update across the board. Ducati mixed and matched components like crazy, so that the smaller, cheaper Monsters got lower-end brakes and suspension, while the bigger bikes received the better stuff from Brembo, Marzocchi and Showa. High-end models got standard Öhlins kit.