The Yamaha TTR225 is a versatile dual-sport motorcycle produced from 1999 to 2004, renowned for its user-friendly nature and reliability, making it an excellent choice for beginner riders and recreational trail use. This first-generation model features a 4-stroke, air-cooled 223cc engine, a 5-speed manual transmission, and a steel diamond frame, all contributing to its accessible performance and dependable operation. With its manageable power delivery and suitability for various terrains, the TTR225 has earned a reputation for being a forgiving and capable machine, often praised in enthusiast communities for its robust build and straightforward design. This comprehensive factory service repair manual provides in-depth information for all Yamaha TTR225 models manufactured between 1999 and 2004. It covers a wide array of essential topics, including detailed maintenance procedures, step-by-step repair instructions for all major systems such as the engine, fuel, drivetrain, chassis, and electrical components, as well as diagnostic and troubleshooting guides. The manual is designed to assist professional technicians, mechanics, and knowledgeable owners in maintaining, repairing, and optimizing their TTR225, ensuring its longevity and optimal performance through factory-level insights and clear, detailed instructions.