This manual pertains to the Cagiva T4 350/R-E and T4 500/E models, dual-sport motorcycles produced during the late 1980s and early 1990s. These Italian-engineered machines are recognized for their rugged design and off-road capabilities. They typically feature robust single-cylinder, liquid-cooled engines, a 6-speed transmission, and a steel trellis frame, making them suitable for both on-road and trail riding. This comprehensive workshop manual provides essential information for owners, mechanics, and technicians. It covers a wide array of systems, including detailed procedures for engine disassembly, overhauling, and reassembly, as well as maintenance for the lubrication circuit, fuel system, ignition system, cooling system, exhaust system, transmission, frame, wheels, and brakes. The manual also includes troubleshooting guides, adjustment procedures, specific tool usage, and detailed torque settings and tolerances, ensuring proper diagnosis, repair, and upkeep of these vehicles.