This manual covers the 2005 KTM 400 LC4 and 660 LC4 models, renowned performance dual-sport motorcycles built for enthusiasts and off-road riding. These Austrian-made machines are characterized by their robust LC4 single-cylinder engine, celebrated for its torque and versatility, and high-quality WP suspension components designed for exceptional off-road capability. The lightweight yet strong trellis frame further enhances their agility and performance. The LC4 platform represents a mature iteration of KTM's long-standing heritage in producing powerful and capable motorcycles.

This comprehensive workshop service manual provides detailed, dealer-level information for all repairs and maintenance procedures for the 2005 KTM 400 LC4 and 660 LC4. It covers every aspect of the vehicle, from engine overhaul, transmission, chassis, and suspension to brakes, electrical systems, and bodywork. Included are step-by-step repair instructions, diagnostic procedures, troubleshooting guides, and essential technical data such as torque specifications and fluid capacities. This manual is an indispensable resource for owners, mechanics, and technicians seeking to maintain and repair these performance motorcycles effectively.