This manual covers the Yamaha WR400F and WR426F motorcycles produced in 2000. These high-performance off-road competition and enduro motorcycles are renowned for their lightweight, agile chassis and powerful liquid-cooled, 4-stroke, DOHC single-cylinder engines, designed to deliver strong torque across a broad RPM range. Building on Yamaha's extensive racing heritage, the WR series offers robust engineering and exceptional performance for challenging off-road conditions. The WR400F features a 397cc engine, while the WR426F boasts a 426cc displacement, both offering significant power suitable for demanding terrain.

This comprehensive factory service manual provides detailed information for owners, mechanics, and technicians. It covers all aspects of maintenance, troubleshooting, diagnostics, and tuning, from routine service procedures such as oil changes and air filter cleaning to complete engine and chassis overhauls. The manual includes step-by-step instructions, abundant illustrations, and critical torque specifications for engine mechanicals, fuel and exhaust systems, transmission, suspension, brakes, and the electrical system. It is designed to ensure the optimal performance, reliability, and longevity of your 2000 Yamaha WR400F or WR426F motorcycle.