This manual covers the KTM 400 LC4 and 660 LC4 models, produced between 1998 and 2003. These motorcycles are part of the renowned LC4 engine family, known for their robust single-cylinder performance and versatility in dual-sport and enduro applications. KTM, an Austrian manufacturer with a strong motorsport heritage, engineered these bikes to offer a distinctive thumper character and significant torque, making them capable on a variety of terrains. The LC4 platform has a long lineage, and these specific models represent key iterations within that development, competing in a segment that valued ruggedness and performance.

This comprehensive factory service and repair workshop manual provides detailed information essential for the maintenance and repair of your KTM LC4 motorcycle. It covers all major systems, including engine mechanicals, fuel and ignition systems, transmission, suspension, brakes, and electrical components. The manual offers step-by-step procedures for routine maintenance, component rebuilding, and troubleshooting, along with critical technical specifications, torque values, and wiring diagrams. Its purpose is to equip owners, mechanics, and technicians with the knowledge needed to ensure the optimal performance, reliability, and longevity of these specialized machines.