The YZF-R1, model code RN09, represents a pinnacle of sportbike engineering from its 2004 production year. As the flagship superbike, it embodies a design philosophy focused on cutting-edge performance and rider-centric handling, building upon a rich motorsport heritage. This model features a high-revving, 998cc inline-four engine, a lightweight aluminum Deltabox frame, and advanced suspension geometry, all contributing to its reputation as a formidable machine in its class, comparable to other high-performance sportbikes of the era. This comprehensive workshop service and repair manual provides in-depth technical guidance for the YZF-R1 (RN09) 2004 model. It covers all essential systems, including the engine, transmission, chassis, brakes, and electrical components, detailing scheduled maintenance, troubleshooting procedures, and complete repair instructions. With expert-level detail, including diagnostic flowcharts and specific torque values, this manual is an indispensable resource for owners and technicians seeking to maintain, diagnose, and repair the vehicle to optimal performance standards.