The Yamaha Majesty 400 ABS, produced between 2004 and 2005, is a maxi-scooter designed for both urban commuting and longer touring journeys, offering a comfortable ride, ample storage, and the reliability synonymous with engineering. Its powerful 395 cc liquid-cooled engine, coupled with an automatic CVT transmission and a standard Anti-lock Braking System (ABS), provides a blend of performance and safety. The Majesty 400 is characterized by its spacious under-seat storage, capable of accommodating two full-face helmets, and a robust build that has contributed to a reputation for quality and durability in the powered products market. This comprehensive service manual, written in Italian, provides detailed guidance for the maintenance and repair of the Yamaha Majesty 400 ABS (YP400). It covers a wide array of systems, including the engine, automatic CVT transmission, chassis, ABS braking system, and electrical components, with in-depth procedures for everything from routine maintenance like oil changes and filter replacements to complete engine overhauls and component disassembly. The manual includes hundreds of images, diagrams, and electrical schematics, along with diagnostic troubleshooting steps and precise torque specifications, making it an indispensable resource for owners, technicians, and mechanics aiming to preserve the optimal performance and longevity of their vehicle.