The Yamaha TT350 and TT350S are dual-sport motorcycles produced from 1985 to 2000, renowned for their reliable air-cooled engines, robust chassis, and capable off-road performance combined with street legality. These models represent a commitment to producing dependable and versatile machines, offering a balanced experience for riders tackling varied terrains. With a 4-stroke, single-cylinder engine displacing approximately 347cc, featuring SOHC and CDI ignition, the TT350 series provides a solid foundation for both adventure and everyday riding. Its heritage is rooted in extensive experience in motorcycle engineering, particularly in the dual-sport segment, positioning it as a capable alternative to contemporaries like the Honda XR and Suzuki DR series. This comprehensive service repair workshop manual provides detailed information for the Yamaha TT350 and TT350S models spanning the years 1985 through 2000. It covers all essential aspects of maintenance, repair, and troubleshooting, including complete engine overhaul, transmission service, fuel system maintenance, electrical system diagnostics, suspension and brake servicing, and frame and bodywork. The manual offers step-by-step instructions for routine maintenance, disassembly and assembly procedures, and in-depth technical specifications. Its purpose is to empower owners, mechanics, and technicians with the knowledge required to effectively maintain, diagnose, and repair these motorcycles, ensuring optimal performance and longevity.