This manual pertains to the 1990 Suzuki RG500, a high-performance motorcycle renowned for its racing heritage, derived from successful Grand Prix machines. Featuring a potent 498cc two-stroke, liquid-cooled V4 engine producing approximately 95-100 horsepower, the RG500 offers an exhilarating riding experience. Its engineering is characterized by a lightweight chassis, dual front disc brakes, and a 6-speed transmission, all contributing to its exceptional performance and handling. This iconic model, produced from 1985 to 1990, represents a significant era in sportbike technology and design. This comprehensive service repair manual provides essential information for owners, DIY enthusiasts, and independent repair shops. It covers a wide array of critical systems, including general information, periodic maintenance, engine, fuel system, exhaust, cooling, lubrication, chassis, and electrical systems, along with emission control information and wiring diagrams. The manual offers step-by-step repair instructions, detailed diagnostic procedures for systems like the fuel injection, and guidance on essential maintenance tasks specific to two-stroke engines, such as power valve cleaning and carburetor tuning. With dealer-level technical depth and numerous illustrations, this English-language manual is designed to empower users to maintain and repair their Suzuki RG500 effectively, enabling cost savings and ensuring optimal performance.