The YJ125S, produced in 2003, is a lightweight scooter designed for efficient urban commuting, offering a blend of fuel economy and user-friendly operation. Building on a legacy of reliable and performance-oriented vehicles, this model is characterized by its practical design and accessibility within its market segment, competing with other commuter scooters. Its engineering emphasizes stability and rider comfort, making it a dependable choice for daily transportation needs. This comprehensive manual provides detailed guidance for the full service, repair, maintenance, and restoration of your YJ125S. Covering all major systems including the engine, transmission, fuel, electrical, brakes, and suspension, it offers step-by-step instructions, troubleshooting procedures, and essential technical specifications. This resource is designed to empower owners and technicians alike, enabling them to maintain the vehicle's optimal performance and longevity, thereby reducing reliance on external service centers.