This manual covers the 450 Mark 3, produced between 1967 and 1970. Renowned for its performance-oriented engineering and the innovative Desmodromic valve system, the 450 Mark 3 represents a significant part of heritage of powerful single-cylinder motorcycles. This model is appreciated by collectors for its historical importance and engineering prowess, offering a robust riding experience characteristic of legacy. This factory service repair manual in English provides comprehensive guidance for the maintenance and repair of the 450 Mark 3. It details procedures for all major systems, including the engine, fuel system, clutch, transmission, brakes, suspension, steering, frame, and electrical components. The manual includes step-by-step instructions for routine maintenance, troubleshooting, disassembly, and reassembly, alongside critical technical specifications and hundreds of illustrations, making it an essential resource for owners and technicians alike.