The Yamaha WR400F, produced between 1998 and 1999, represents a significant entry in the off-road and dual-sport motorcycle segment. Evolving from Yamaha's successful YZ motocross lineage, this 396cc, liquid-cooled, 5-valve DOHC single-cylinder machine was engineered for potent performance and rugged durability. Known for its strong, torquey engine and capable chassis, the WR400F offered riders a potent package for trail riding and enduro competition. Its robust construction and focus on essential off-road capabilities made it a respected choice within its class, embodying Yamaha's heritage in performance-oriented off-road vehicles.

This comprehensive Factory Service Repair Manual and Parts Diagrams is designed to be an indispensable resource for owners and technicians of the Yamaha WR400F (1998-1999 models). Covering a vast array of systems including the engine, fuel, ignition, transmission, suspension, brakes, and electrical components, this manual provides detailed maintenance procedures, troubleshooting guides, and step-by-step repair instructions. With hundreds of high-quality illustrations, full-color wiring diagrams, and exploded view parts diagrams, it facilitates accurate identification, servicing, and repair. The manual's extensive coverage, presented in English, French, and German, ensures users have the factory-level technical information necessary to maintain their WR400F effectively.