This manual covers the All-Terrain Vehicle, a 1990 model. Engineered for performance and reliability, the 350 features a 347 cc, 2-stroke, liquid-cooled, parallel twin engine with dual Mikuni carburetors, a 6-speed transmission, and a wet, multiple-disc clutch. Its robust chassis is equipped with independent double wishbone front suspension and a swingarm rear suspension, both offering significant travel, complemented by dual hydraulic disc front brakes and a hydraulic disc rear brake. The vehicle is designed for demanding off-road use, offering a thrilling and capable riding experience. This Service Manual, written in English, provides comprehensive guidance for the diagnosis and servicing of the 350. With over 320 pages, it details essential maintenance procedures, including lubrication, cooling system care, and tune-up specifications such as spark plug type and gap. It also covers technical specifications for the engine, transmission, chassis, suspension, and electrical systems, along with troubleshooting advice. This resource is invaluable for owners, mechanics, and technicians seeking to maintain the optimal performance and longevity of their 1990 350.