This manual covers the 400 LC4 and 660 LC4 models from 2003 onwards, renowned for their powerful liquid-cooled, four-stroke, single-cylinder LC4 engine architecture. These motorcycles, built with Austrian engineering heritage, are designed for demanding off-road, enduro, supermoto, or adventure applications, offering robust performance and a distinctive riding experience. The LC4 engine, a cornerstone of the lineup, has undergone decades of refinement, with the models covered here representing a significant iteration focused on reliability and power delivery, suitable for both spirited riding and long-distance journeys.

This comprehensive service repair workshop manual provides detailed, model-specific information for all maintenance and repair needs. It covers every aspect of the vehicle, from routine maintenance procedures like oil changes and valve adjustments to complete engine overhauls, transmission servicing, and electrical system diagnostics. The manual includes detailed schematics, torque specifications, troubleshooting guides, and step-by-step instructions, empowering owners and technicians to maintain the integrity and performance of their 400 LC4 or 660 LC4.