The Grizzly 350 and 400 series All-Terrain Vehicles (ATVs), identified by model codes YFM350 and YFM400, represent a robust line of 2WD utility vehicles produced between 2003 and 2012. Engineered with a renowned commitment to reliability and durability, these ATVs are designed to tackle a wide range of terrains and tasks. They feature air-cooled, 4-stroke engines with displacements of approximately 348cc for the 350 models and 386cc for the 400 models, paired with an automatic Continuously Variable Transmission (CVT) system, often referred to as Ultramatic. These vehicles are well-suited for recreational trail riding, farm work, and light-duty hauling, offering a balance of power and maneuverability. This comprehensive factory service manual provides in-depth coverage for the Grizzly 350 and 400 models from 2003 through 2012. It serves as an essential resource for owners and technicians, detailing full service, repair, and troubleshooting procedures. The manual covers all major systems, including the engine, fuel, ignition, transmission, drivetrain, suspension, brakes, steering, and electrical systems, along with frame and body components. Within its hundreds of pages, you will find step-by-step instructions for scheduled maintenance, routine inspections, engine and transmission overhauls, carburetor adjustments, and electrical diagnostics, all supported by detailed photos and diagrams to ensure accurate and efficient upkeep of your ATV.