The Yamaha TZ125, model code TZ125G1, is a high-performance racing motorcycle produced between 1990 and 2005. Engineered for competition, this two-stroke, single-cylinder machine typically features a 124cc displacement and delivers power in the range of 30-40 HP, making it a formidable contender in its class. With a focus on agility and rider control, the TZ125 is built upon an extensive heritage in motorcycle racing, embodying a commitment to performance and reliability on the track. Its lightweight design, estimated to be under 100 kg dry weight, combined with a precise 6-speed sequential gearbox and a responsive chassis, ensures a thrilling and competitive racing experience. This comprehensive workshop repair service manual provides in-depth coverage for all TZ125 models, engines, trims, and transmission types from 1990 to 2005. Written in English, it serves as an essential resource for owners, mechanics, and racing teams, detailing scheduled maintenance, routine service, and step-by-step repair procedures for every major system, including the engine, fuel, cooling, drivetrain, chassis, and electrical systems. The manual offers professional-level diagnostic and troubleshooting guidance, ensuring the optimal performance and longevity of your TZ125. Its digital format allows for easy navigation, printing of specific sections, and zoom functionality, providing access to critical information.