This manual covers 450 EXC, 400 EXC, and 520 SX models produced between 2000 and 2003. These high-performance off-road motorcycles are renowned for their power, agility, and exceptional capability in enduro and motocross applications. Built with a focus on off-road competition and trail riding, models from this era are celebrated for their robust engineering, reliable performance, and winning heritage.

This comprehensive workshop service manual provides in-depth information on all aspects of service, maintenance, and repair for these models. It details engine assembly and disassembly, fuel and electrical systems, transmission, chassis components, brakes, and bodywork. The manual also includes essential troubleshooting guides, diagnostic procedures, and technical specifications, making it an indispensable resource for owners and technicians seeking to maintain and optimize their motorcycles.