This comprehensive Yamaha DT250 DT400 Service and Repair Manual covers all aspects of maintenance, repair, and troubleshooting for your 1977-1979 motorcycle. This detailed manual, written for professional mechanics and technicians, provides step-by-step instructions and hundreds of high-quality illustrations and diagrams to guide you through every procedure. It includes everything you need to confidently perform repairs and service your motorcycle, from basic maintenance tasks to complex engine overhauls. With this manual, you'll have the same information and expertise used by professional mechanics, allowing you to diagnose and fix problems, and ensure your Yamaha DT250 or DT400 runs smoothly for years to come.

The Yamaha DT250 and DT400 were a pair of highly successful dual-sport motorcycles produced by Yamaha between 1977 and 1979. These machines were renowned for their versatility, offering a thrilling blend of on-road performance and off-road capability. The heart of the DT250 was a 249cc, two-stroke, single-cylinder engine, while the DT400 boasted a more powerful 399cc, two-stroke single. Both models featured a six-speed transmission, providing ample gear choices for both road and trail riding. The DT models were known for their lightweight and agile handling, thanks to their tubular steel frame and telescopic front forks with adjustable preload. The rear suspension consisted of dual shocks, also with adjustable preload. These bikes were exceptionally popular with riders seeking a machine that could tackle challenging trails and still deliver a comfortable and enjoyable ride on paved roads. The Yamaha DT250 and DT400 were not just powerful and capable motorcycles but also visually striking. Sporting a distinctive 70s aesthetic, they featured a bold, angular design with chrome accents and a large, two-piece headlight. The fuel tank, sculpted to offer excellent rider ergonomics, was fitted with a rubber tank pad, providing a comfortable grip for riders. The DT series also incorporated several practical features, including a comfortable, dual-seat setup, a large, easily-accessible luggage rack, and an innovative "dual-purpose" front fender that offered both off-road protection and a streamlined look for road riding. The Yamaha DT250 and DT400 are considered iconic models in the history of dual-sport motorcycles. Their combination of power, agility, and versatility made them highly sought after by enthusiasts of both on- and off-road riding. Despite being discontinued in 1979, these machines continue to be admired and cherished by motorcycle enthusiasts worldwide, serving as a testament to Yamaha's enduring legacy in the realm of dual-sport motorcycles.