The YZF-R1S and YZF-R1SC, produced between 2003 and 2004 under the RN09 generation, represent a pinnacle of superbike engineering. These models, known for their inline 4-cylinder, 4-stroke, liquid-cooled engines with 5 valves per cylinder and 998cc displacement, deliver exhilarating performance characteristic of a rich motorsports legacy. Designed for performance-oriented sportbike riders and track day enthusiasts, the YZF-R1 of this era revolutionized the liter-class segment with its advanced chassis, aerodynamic bodywork, and impressive power output, rivaling contemporary machines from major manufacturers. This comprehensive Workshop Service Repair Manual is designed to guide owners, mechanics, and technicians through all aspects of maintaining and repairing the YZF-R1S/SC models. Spanning over 450 pages, it covers every system in detail, from complete engine overhauls, fuel and cooling systems, transmission, brakes, suspension, and electrical systems to frame and bodywork. The manual includes detailed step-by-step instructions, torque specifications, troubleshooting guides, and comprehensive wiring diagrams, ensuring that all maintenance and repair procedures are carried out correctly and efficiently.