This manual provides comprehensive technical information for the motocross models manufactured between 1994 and 2004. These highly regarded machines are known for their potent two-stroke engines, advanced suspension systems, and competitive performance on the track, reflecting a strong heritage in off-road racing. The KX line consistently earned accolades for its aggressive power delivery and agile handling, making it a favorite among professional racers and enthusiasts alike. This service repair manual is designed to assist owners, mechanics, and technicians in maintaining and repairing these performance-oriented motorcycles. It covers all major mechanical, electrical, and chassis systems, including detailed procedures for engine overhaul, carburetor tuning, suspension servicing, and electrical system diagnostics. With comprehensive coverage of maintenance schedules, repair instructions, troubleshooting guides, and precise technical specifications such as torque values and clearances, this manual is an essential resource for ensuring the optimal performance and longevity of your KX125 or KX250.