This document pertains to the Monster S2R 800 Dark, a naked sportbike produced in 2006. As part of the second generation Monster lineup, this model embodies a legacy of performance-oriented motorcycles, characterized by its iconic minimalist styling, exposed steel trellis frame, and the distinctive Desmodromic valve actuation of its air-cooled L-twin engine. The S2R 800 Dark variant specifically features a matte black finish and was positioned as an accessible yet capable machine for enthusiast riders. Its engineering emphasizes rider feedback and a direct connection to the road, offering a potent blend of Italian design and exhilarating performance. This comprehensive workshop service repair manual provides detailed guidance for all mechanical and electrical aspects of the 2006 Monster S2R 800 Dark. Covering everything from routine maintenance procedures, such as oil changes and valve adjustments (Desmo service), to in-depth repair protocols for the engine, transmission, chassis, and electrical systems, this manual serves as an essential resource. It includes extensive technical specifications, troubleshooting guidance for common issues, and numerous illustrations to facilitate accurate diagnosis and repair, empowering owners and technicians to maintain the vehicle's optimal performance and longevity.