The 400 SX, 450 SX, 400 MXC, 450 MXC, 400 XC, and 450 XC models represent high-performance off-road competition motorcycles from an Austrian manufacturer renowned for its racing heritage. These models, produced between 2000 and 2007, are powered by the robust LC4 4-stroke, single-cylinder engine, available in 400cc (approximately 373cc-398cc) and 450cc (approximately 435cc-449cc) displacements. They are engineered for demanding motocross, marathon cross country, and cross country racing, featuring powerful engines, strong steel trellis frames, and advanced suspension systems. These machines are built for performance and reliability in competitive environments.

This comprehensive workshop service repair manual, provided in English, is designed to assist owners, mechanics, and technicians in maintaining and repairing the specified models. It covers a wide range of critical areas, including complete engine overhauls, transmission servicing, chassis components, and the electrical system. Detailed procedures for regular maintenance, such as oil changes, filter replacements, and valve clearance checks, are included alongside in-depth repair instructions for engine, gearbox, suspension, and electrical systems. The manual also offers troubleshooting guidance for common issues, ensuring the optimal performance and longevity of these competition motorcycles.