The Suzuki GSXR400, also known as the GSX-R400 GK73A, represents the second generation of this iconic sportbike, produced in 1987. This model is part of Suzuki's renowned GSX-R lineage, celebrated for its racing-inspired design and performance. Featuring an inline four-cylinder, liquid-cooled 398cc engine, it delivers approximately 55-60 PS and is equipped with a 6-speed constant mesh transmission and a wet multi-plate clutch. Its engineering emphasizes agility and responsiveness, making it a capable machine for sport riding. The GSXR400 is built upon Suzuki's legacy of innovation in sportbike technology, offering a blend of power and handling that defined its era. This comprehensive service repair manual provides detailed information for the Suzuki GSXR400 (1987). It covers all essential aspects of service and repair, including in-depth maintenance procedures, troubleshooting guides, and diagnostic support. The manual details the engine mechanicals, fuel and ignition systems, transmission, suspension, brakes, electrical system, cooling system, frame, and bodywork. It also includes procedures for disassembly, assembly, cleaning, and reinstallation, along with technical specifications and fluid requirements. This resource is designed to assist professional technicians, experienced DIY mechanics, and owners in effectively maintaining and repairing their GSXR400, ensuring optimal performance and longevity.