The Yamaha XS360 and XS400 series, produced from the late 1970s through the mid-1980s, represent Yamaha's successful entry into the middleweight parallel-twin motorcycle market. These standard and cruiser-style motorcycles, powered by air-cooled, 4-stroke parallel-twin engines with SOHC valvetrain, offered a blend of reliable performance and accessible engineering, making them popular choices for new riders and enthusiasts. Known for their mechanical simplicity and distinctive styling, these models provided a solid foundation for commuting and light touring, competing effectively within their segment against offerings from Honda, Kawasaki, and Suzuki.

This comprehensive factory service manual provides detailed guidance for the maintenance, repair, and troubleshooting of Yamaha XS360 and XS400 motorcycle variants, covering engine codes such as 2M6, 14E, 15R, 4A0, 4A1, 4D5, 4H7, 1U2, and 1U6. Within its approximately 300-500 pages, owners and technicians will find in-depth information on engine systems, fuel delivery, transmission, electrical components, brakes, suspension, and frame. The manual includes essential maintenance schedules, fluid specifications, diagnostic procedures for common issues like carburetor problems and electrical faults, and step-by-step repair instructions, ensuring the longevity and optimal performance of these classic Yamaha machines.