The 1985-1987 Yamaha Tri-Z 250 (YTZ250) represents a significant model in Yamaha's performance ATV lineage, building upon earlier designs with a potent two-stroke, liquid-cooled 236cc engine. This model is recognized for its sporty handling and powerful performance, making it a notable entry in the early performance ATV market. Its engineering quality and reliability, hallmarks of Yamaha's manufacturing, ensure a robust and capable machine for enthusiasts and riders. This comprehensive factory service repair manual, written in English, provides complete information for the maintenance, troubleshooting, and repair of the Yamaha Tri-Z 250. It covers all essential systems, including the engine, transmission, brakes, electrical system, and suspension, detailing procedures from general maintenance and lubrication to complex component replacement and diagnostics. The manual includes critical technical data, torque specifications, and detailed diagrams, making it an indispensable resource for technicians, mechanics, and owners dedicated to preserving the optimal performance and longevity of their Tri-Z 250.