BMW is currently the most successful provider of large motorcycles in the German market. The most important model series from the Bavarian manufacturer is, as it has been for many years, the R series with its characteristic boxer engine. Among the motorcycles equipped with this engine, the Enduro version designated GS regularly leads the registration statistics. This book presents the R 1200 GS and its siblings R 1200 RT, RS, and R in their current version with a liquid-cooled DOHC four-valve engine in detail and provides everything the owner needs to know for maintenance and repair: - a detailed description of maintenance procedures - the correct techniques for removing and installing individual parts - measurements, torque specifications, fluid capacities - colored wiring diagrams. The DOHC boxer engines introduced here, used since 2010, are the first with liquid cooling.