YZ400F motorcycle

399cc / 55ps/9,000rpm

Displacement / Max output

Liquid-cooled, 4-stroke, DOHC 5-valve single

Engine type

2176 / 827 / 1303

Overall length / width / height (mm)

Thisis Yamaha's first 4-stroke production motocross machine developedaround the technology of the YZM400F factory machine that won six racesof the '97 500cc Motocross World GP and the final round of the '97 AMASupercross series. It has been developed with the goal of being nothingless than "the fastest 4-stroke motocrosser."
This model's newlydeveloped power unit adopts a lightweight, compact design with aliquid-cooled DOHC 5-valve single-cylinder format. A single-shaftbalancer is also adopted to reduce rider fatigue. FCR carburetors areadopted to achieve superior response.
The chassis structure shares the same basic structure and dimensions asthat on the YZ250 production motocrosser with its 24-year record ofproven competitive performance. Also adopted is a new semi-doublecradle frame incorporating an integrated oil tank that uses thedown-tube and the interior of the gussets as the oil tank to ensuresufficient ground clearance.
In its many other features, like the suspension and brakes, the samecomponents as those on the YZ250 are used to ensure the sameoutstanding performance characteristics and competitiveness.
In this way the YZ400F is answering the needs of the 500cc World GP,where 4-stroke machines are drawing increasing attention, and the U.S.market where users have been hoping for the appearance of 4-strokecompetition machines.

YZ400F