This manual covers the KTM 125 SX, 250 SX, 125 EXC, and 250 EXC off-road motorcycles produced in 2002. These liquid-cooled, two-stroke, single-cylinder motorcycles are engineered for high-performance motocross and enduro disciplines, featuring advanced WP suspension and robust chassis designs. Known for their competitive edge and reliability in demanding off-road conditions, KTM models of this era have a strong heritage in racing and are celebrated for their powerful engines and responsive handling.

The purpose of this official factory service manual is to provide comprehensive guidance for the maintenance, diagnosis, and repair of these vehicles. It details procedures for engine disassembly and assembly, fuel and ignition systems, cooling and lubrication, clutch, gearbox, and the power valve system. This manual includes specific torque values, clearances, wear limits, and troubleshooting steps, enabling owners and technicians to ensure optimal performance and longevity of their KTM off-road motorcycles.