This manual covers the 2007 450 SX-F, 505 SX-F, and 450 SXS-F models, representing high-performance motocross and supercross competition off-road motorcycles. These models are known for their powerful engines, featuring 450cc and 505cc displacement options, advanced suspension, and lightweight chassis designed for professional racing. Built with a renowned 'Ready to Race' philosophy, these motorcycles offer competitive performance against other leading brands in their class. The first generation of the SX-F/SXS-F series for this engine platform, utilizing the LC4 engine architecture, embodies dedication to off-road excellence. This comprehensive repair and workshop manual provides detailed guidance for the maintenance and repair of the 2007 450 SX-F, 505 SX-F, and 450 SXS-F engines. It covers a wide range of essential systems, including general information, routine maintenance, engine removal and installation, fuel system, lubrication and cooling, transmission, steering, shocks, bodywork, intake and exhaust, and the electrical system. The manual details procedures for diagnosis, repair, overhaul, adjustment, inspection, and troubleshooting, offering comprehensive rebuild guidance, precise torque specifications, clearances, and diagnostic charts. This resource is invaluable for owners, mechanics, and technicians seeking to maintain and repair these competition motorcycles to optimal performance standards.