USA YZ450F A WINNER RIGHT OUT OF the CRATE. 2015 Yamaha Motor Corp. the critics agree: the YZ450F is the one to beat. Motorcycles Motocross DX0117167431901500289 DX1 . Completely re-engineered just last year with new EFI engine an entirely new frame minimized body work and new suspension components providing for excellent mass centralization and class leading 450 power with 250-style handling...