The Yamaha WR450F is an off-road motorcycle made by Yamaha Motor Company. It currently has a 450 cc (27 cu in) liquid-cooled single-cylinder engine. First offered in 1998 at 400cc, it shared many components and design concepts with the YZ400F motocross model.
It is basically the YZ450F detuned slightly for more controllable power, with a headlight and lighting coil, softer suspension, a kickstand, lower noise specifications, larger radiators and lower emissions. The WR in the name indicates a wide-ratio gear box common to most enduro or trail bikes and stands in contrast to the close-ratio gearbox essential to a motocross racer. Over the years the WR has benefited from the advances made in the YZ motocross version gaining displacement and advancements such as an aluminum frame and improved suspension.