The 450 SX-F and 450 SXS-F, produced in 2007, are high-performance motocross motorcycles renowned for their lightweight design, powerful engines, and agile handling. These track-focused machines, built with off-road racing heritage in mind, compete with leading models from other manufacturers and have a history of championship wins. They feature a 4-stroke, single-cylinder LC4-based engine with a displacement of approximately 449cc, liquid cooling, and a hydraulically operated, multi-disc wet clutch. The chassis is constructed from a chromoly steel trellis frame, providing a robust yet light foundation for the vehicle's performance capabilities. This comprehensive workshop service repair manual in English covers the 450 SX-F, 450 SXS-F, 505 SX-F, and 505 SXS-F models. It provides detailed information on engine disassembly, assembly, tuning, and diagnostics, including carburetor specifications and fuel system guidance. The manual also details transmission maintenance, chassis inspection, electrical system troubleshooting, and brake system servicing. With hundreds of pages of content, it serves as an authoritative resource for owners and technicians, offering procedures for routine maintenance, repairs, and troubleshooting to ensure optimal performance and longevity of the motorcycle.