This manual covers the YFM200 Moto-4 All-Terrain Vehicle (ATV), including sub-models YFM200N, YFM200DXS, YFM200DXT, and YFM200U, produced between 1985 and 1989. Known for its reliable single-cylinder, 4-stroke engine and solid construction, the Moto-4 was designed as a capable recreational ATV, embodying a heritage in motorsports. Its engineering focused on providing dependable performance for trail riding and general utility, making it a popular choice in its segment during the 1980s ATV development era. This comprehensive Factory Service Manual provides in-depth technical information for the maintenance, diagnosis, and repair of the YFM200 Moto-4. It details procedures for the engine, cooling system, carburetion, drivetrain, chassis, and electrical systems, offering step-by-step instructions, troubleshooting guides, and detailed illustrations. This manual is an essential resource for DIY mechanics, technicians, and owners seeking to maintain their vehicle's optimal performance and longevity, covering everything from routine servicing to complex component overhauls.