This manual covers the KTM 400 LC4 and 660 LC4 models from 1998. These motorcycles are known for their powerful single-cylinder engines, rugged construction, and versatility, often utilized in enduro and supermoto applications. The LC4 platform, developed by KTM, a company with a strong Austrian heritage in off-road motorsports, is recognized for its robust performance and torque, making it a capable machine for demanding riding conditions.

This comprehensive service and repair manual provides detailed information for maintaining and repairing your KTM LC4. It covers a wide range of systems including engine mechanicals, lubrication, cooling, fuel, ignition, exhaust, transmission, drivetrain, suspension, brakes, wheels, tires, electrical systems, and frame/bodywork. Procedures range from routine maintenance and troubleshooting to complete engine and gearbox rebuilds, suspension servicing, and electrical diagnostics, ensuring your vehicle remains in optimal condition.