This workshop service repair manual covers Mongoose 50, Mongoose 90, KXR 50, and KXR 90 models from 2004 through 2014. These ATVs are known for their reliable 4-stroke, air-cooled engines, available in 49.5 cc and 86.5 cc displacements, paired with an automatic CVT transmission. Designed for recreational use and targeting younger riders, the Mongoose and KXR lines are recognized for offering value-oriented performance. The vehicles feature dependable chassis, braking systems, and essential lighting, making them suitable for various off-road activities. This comprehensive manual provides in-depth guidance for all service and repair procedures. It includes detailed step-by-step instructions, clear illustrations, and diagnostic information for the engine, transmission, drivetrain, fuel, ignition, electrical, cooling, braking, suspension, and steering systems. Owners and technicians will find essential maintenance schedules, troubleshooting flowcharts, technical specifications, torque values, and wiring diagrams. The manual is designed to empower users to perform routine maintenance, complex repairs, and adjustments, ensuring the longevity and optimal performance of their ATV.