This workshop service repair manual covers the Polaris Xpress 300 and Sport 400 ATVs manufactured for the 1998 and 1999 model years. These ATVs, known for their robust two-stroke, fan-cooled, single-cylinder engines, offered reliable performance for recreational and utility use. The Xpress 300, with its 299 cc engine, and the Sport 400, powered by a 398 cc engine, both feature automatic CVT transmissions and are equipped with hydraulic disc brakes for effective stopping power. A brand with roots dating back to 1954, was recognized during this era for its growing presence and innovation in the ATV market. This comprehensive manual provides complete service and repair procedures from A to Z, intended for ATV owners and independent repair technicians. It details maintenance schedules, troubleshooting guides, and step-by-step repair instructions for all major systems, including the engine, transmission, drivetrain, suspension, braking, steering, and electrical components. Covered maintenance includes oil changes, filter replacements, and lubrication, while repair sections address everything from basic component adjustments to complete engine and transmission overhauls. The manual aims to empower users to perform maintenance and repairs efficiently, potentially saving costs and ensuring the longevity of their vehicles.