This document serves as a comprehensive service repair manual for the 2004 Majesty YP400S, a maxi-scooter known for its blend of comfort and practicality. Engineered by a manufacturer with a strong heritage originating from Japan, this model offers a robust 395cc four-stroke, liquid-cooled engine with fuel injection, delivering approximately 27.5 HP. Its design prioritizes rider convenience, featuring ample underseat storage and an integrated braking system for enhanced safety. The Majesty YP400S was positioned within the maxi-scooter segment, competing with models like the Suzuki Burgman 400 during its production era. This workshop manual provides detailed information essential for maintaining and repairing the Majesty YP400S. It covers a wide range of critical areas, including general information, technical specifications, periodic checks and adjustments, and in-depth procedures for the chassis, engine, cooling system, fuel injection system, and electrical system. The manual includes troubleshooting guides, maintenance schedules, and specific fluid recommendations, all presented with step-by-step instructions and clear diagrams. This resource is designed to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of their vehicle.