The Yamaha DT125, encompassing the DT125RE and DT125X variants produced between 2002 and 2008, represents a robust line of motorcycles renowned for their versatility and enduring performance. Building on extensive heritage in motorcycle manufacturing, these models are designed for a range of uses, from general trail riding to more specialized applications, reflecting the evolution of the DT series. Their engineering prioritizes reliability and a responsive riding experience, making them a popular choice for riders seeking a capable and dependable machine. This comprehensive workshop repair service manual provides detailed guidance for the maintenance, repair, and diagnostics of all Yamaha DT125RE and DT125X models. It covers essential systems including the engine, drivetrain, chassis, and electrical components, offering step-by-step repair instructions, routine maintenance procedures, and troubleshooting guides. Designed for owners, independent repair shops, and technicians, this manual aims to facilitate efficient and accurate servicing, ensuring the longevity and optimal performance of the vehicle.