This manual covers the 2001 Yamaha WR400F/WR426F, a high-performance off-road motorcycle renowned for its robust build quality and exceptional 4-stroke engine performance. Building on Yamaha's extensive legacy in off-road competition, these models were engineered for demanding terrain, offering a potent combination of power, durability, and agility. The WR400F and WR426F represent significant advancements in their era, designed to deliver reliability and capability for enthusiasts and competitors alike.

This comprehensive service and repair manual provides detailed information essential for maintaining the peak performance and longevity of your Yamaha WR400F/WR426F. It covers a wide range of topics including routine maintenance, troubleshooting, diagnostics, and detailed technical specifications. With step-by-step instructions for component disassembly and reassembly, torque specifications, and wiring diagrams, this manual is an indispensable resource for owners and technicians seeking to perform servicing and repairs effectively.