This manual covers the 125 SX models produced between 1999 and 2003. Known as a potent 125cc two-stroke motocross competition machine, the 125 SX from this era is celebrated for its high-performance, liquid-cooled engine and the agile handling characteristic of steel perimeter frame, often featuring suspension components. These machines were developed with a focus on racing performance and have a strong heritage in off-road motorsports, consistently performing well in their competitive segment against other leading motocross bikes of the time.

This comprehensive workshop service repair manual provides factory-level detail for all maintenance, repair, and diagnostic tasks. It includes extensive coverage of the engine, transmission, suspension, electrical system, fuel and ignition system, brake system, clutch system, exhaust system, and chassis. Within its hundreds of pages, you will find detailed procedures for routine maintenance, complete engine and suspension rebuilds, carburetor adjustments, and electrical troubleshooting, making it an essential resource for owners and technicians aiming to maintain, repair, and optimize their 125 SX.