This manual covers the BMW R90, a classic air-cooled boxer twin motorcycle produced around 1983. Renowned for its robust build quality and the distinctive character of its horizontally opposed engine, the R90 series represented a significant step in BMW's motorcycle lineage, offering both the R90/6 and the sportier R90S variants. These machines were engineered for touring capability and reliable performance, establishing a strong reputation against competitors of their time through their advanced engineering and enduring design.

This comprehensive service and repair manual is designed to assist owners, mechanics, and technicians in maintaining and restoring the BMW R90. It provides detailed information on a wide range of systems, including engine overhaul, carburetor tuning, ignition, lubrication, and cooling systems. Coverage extends to the gearbox, clutch, final drive, chassis components, suspension, steering, brakes, and the complete electrical system. The manual includes procedures for routine maintenance, diagnostic troubleshooting, and complete rebuilds, ensuring the longevity and optimal performance of this iconic motorcycle.