Yamaha Motocross Machine History from 1970 through 2017 This is a video showing Yamaha's motocross models from 1970 through 2017. It starts with the GYT-converted enduro models in the early seventies, moves on to the introduction of the YZ models in 1974 (and the eventual deprecation of the lower-performance MX ones), on into the era of four-strokes and fuel injection. Models shown include the YZ50, YZ60, MX80, YZ80, YZ85, MX100, MX125, YZ125, MX175, YZ175, MX250, YZ250, YZ250F, YZ360, MX400, YZ