The Polaris Sportsman 400 / 500, manufactured in 2004, is a versatile All-Terrain Vehicle (ATV) designed for both recreational riding and demanding utility tasks. Known for its rider-forward seating position, robust engine options available in 400cc and 500cc configurations, and capable suspension featuring Independent Front Suspension (IFS) and a swingarm rear, the Sportsman excels in various terrains. Its Variable Transmission (PVT) with engine braking enhances control, while optional On-Demand All-Wheel Drive provides superior traction. The heritage in ATV innovation is evident in the Sportsman line, which has consistently been recognized for its durability and performance in its class, making it a popular choice for farmers, hunters, and recreational enthusiasts. This comprehensive manual serves as an essential guide for the maintenance and repair of your 2004 Polaris Sportsman 400 / 500 ATV. It covers all critical aspects of the vehicle, including complete engine overhaul, transmission repair, electrical system diagnostics with detailed wiring diagrams, suspension and steering system servicing, and brake system maintenance. The manual also provides in-depth information on fuel and cooling systems, body and frame, routine maintenance procedures, and troubleshooting guides for common and potential issues. With factory-level repair and diagnostic information, rebuild specifications, and instructions for component replacement, this resource empowers owners and technicians to effectively maintain and repair the ATV, ensuring its optimal performance and longevity.