The 1985 Suzuki GSX-R400, chassis code GK71B, represents the first generation of Suzuki's iconic GSX-R sportbike lineage. This air-cooled, 398 cc, 4-cylinder motorcycle, powered by a DOHC engine, was engineered for performance and sport riding, establishing the benchmark for the sportbike category. Its design emphasized race-replica styling and dynamic handling, featuring dual hydraulic disc brakes at the front and a single disc at the rear, complemented by telescopic front forks with adjustable preload and a monoshock rear suspension. With a 6-speed transmission and a wet, multiple-disc clutch, the GSX-R400 delivered an exhilarating riding experience. This comprehensive service and repair manual provides detailed instructions for the maintenance and repair of the 1985 Suzuki GSX-R400. It covers all essential systems, including engine, fuel, lubrication, cooling, electrical, chassis, braking, and suspension components, offering step-by-step procedures, troubleshooting guides, and technical specifications. The manual is designed to assist owners and professional technicians in performing everything from routine maintenance, such as oil changes and spark plug replacements, to complex engine rebuilds and suspension servicing. Its professional quality, extensive diagrams, and detailed illustrations ensure accurate and efficient work, empowering users to maintain their vehicle with confidence.