This comprehensive service repair manual covers the BMW R Series motorcycles, including the R80, R90, and R100 GS and R models produced from 1978 through 1996. These air-cooled, horizontally opposed twin-cylinder boxer engines are renowned for their durability and go-anywhere capability, making them legendary in the touring and adventure riding communities. The manual delves into the intricacies of these robust machines, providing essential information for maintaining their performance and longevity. This full factory service repair manual offers detailed, step-by-step instructions for a wide range of maintenance and repair procedures. It covers all major systems, including the fuel, cooling, engine, clutch, transmission, final drive, brakes, suspension, steering, frame, and electrical systems. With hundreds of photos and illustrations, this English-language manual is designed to assist owners and technicians in performing everything from routine maintenance and troubleshooting to complete engine overhauls and complex diagnostics, ensuring the continued reliability and optimal performance of your BMW R Series motorcycle.