This manual covers the Trail Blazer 400 for the 2003 and 2004 model years. Designed for recreational trail riding and off-road exploration, the Trail Blazer 400 is a capable All-Terrain Vehicle (ATV) known for its balance of performance and maneuverability. A respected manufacturer in the ATV industry, has a legacy of producing innovative off-road machines, and the Trail Blazer line has historically been a popular choice for riders seeking an engaging experience. This vehicle typically features a liquid-cooled, 2-stroke engine, an automatic transmission with a Continuously Variable Transmission (CVT), and hydraulic disc brakes, providing a robust platform for various terrains. This comprehensive workshop service manual provides detailed repair and overhaul procedures for the Trail Blazer 400. It covers essential systems including the engine, transmission, fuel system, ignition system, lubrication system, exhaust system, and electrical system. The manual includes step-by-step instructions for routine maintenance, component removal and installation, assembly and disassembly, and engine and transmission rebuilds. It also references special tool numbers and utilizes WARNING, CAUTION, and NOTE symbols to convey critical information, ensuring that owners and technicians have the accurate and reliable data needed to maintain and repair their vehicle effectively.