This manual covers a range of motorcycles from the early to mid-1980s, including the Z400F-F2, Z500F, Z550F, GPz400, and GPz500 models, spanning the production years of 1983, 1984, and 1985. These models represent a significant evolution in Japanese sportbike design, with the GPz series offering enhanced aerodynamics and performance. Known for their inline-4 cylinder, four-stroke engines, these bikes typically featured DOHC configurations and were available in 400cc and 500/550cc displacements, often equipped with multi-carburetor fuel systems and air or oil cooling. The legacy in performance motorcycles is evident in these models, which were celebrated for their handling and power in their era. This comprehensive Workshop Service Repair Supplement Manual provides essential information for maintaining and repairing these classic motorcycles. It details procedures for engine, chassis, and electrical systems, including scheduled maintenance, disassembly and reassembly, and troubleshooting. Key areas covered include engine rebuilds, carburetor synchronization, valve adjustments, brake system servicing, and electrical diagnostics with detailed wiring diagrams. The manual is designed for DIY enthusiasts, independent repair shops, and owners, offering in-depth technical specifications, torque values, and clearances necessary for accurate work, ultimately aiming to help preserve the performance and longevity of these iconic machines.