The Yamaha Raptor YFM660, also known by its model designation YFM660R, is a high-performance sport All-Terrain Vehicle (ATV) produced from 2001 to 2005. This first-generation model established a benchmark in its segment, celebrated for its powerful 660cc liquid-cooled, four-stroke engine and agile handling, making it a popular choice for enthusiasts and competitive riders. Building on a heritage of innovation, the YFM660R featured a 5-speed manual transmission with reverse, hydraulic disc brakes for strong stopping power, and a robust chassis designed for performance riding. Its advanced features and engineering quality positioned it as a leader in the sport ATV market during its production years, known for its exhilarating performance and rider engagement. This comprehensive workshop service manual provides detailed guidance for the maintenance, repair, and overhaul of the Yamaha Raptor YFM660R for the model years 2001 through 2005. Covering a vast array of systems, including engine mechanicals, fuel and ignition systems, transmission, electrical components, chassis, brakes, and bodywork, this manual is an essential resource. It includes step-by-step repair instructions, troubleshooting guides, technical specifications, torque values, and safety guidelines. Whether you are an owner performing routine maintenance or a technician undertaking complex repairs, this manual equips you with the knowledge to ensure the optimal performance and longevity of your YFM660R.