The 450 Mark 3, including the Mark 3 Desmo variant, represents a significant offering, produced between 1967 and 1970. This model is recognized for its Italian engineering prowess and distinctive Desmodromic valve actuation system, a hallmark of the brand. Designed for riders who appreciate performance and classic motorcycle heritage, the 450 Mark 3 embodies the spirit of sporting motorcycles from its era, offering a unique blend of power and handling characteristic of its renowned reputation. Its robust construction and iconic design make it a sought-after machine for enthusiasts and collectors alike. This comprehensive workshop service repair manual provides detailed guidance for the 450 Mark 3 models from 1967 to 1970. It covers all essential aspects of maintenance, repair, and troubleshooting, including in-depth engine disassembly and reassembly, gearbox servicing, electrical system diagnostics with wiring diagrams, and maintenance of the chassis, suspension, braking, and fuel systems. With step-by-step instructions, hundreds of illustrations, and clear procedures for routine maintenance, tune-ups, and complex repairs, this manual is an indispensable resource for owners and technicians aiming to preserve the optimal performance and longevity of their 450 Mark 3.