The Suzuki Eiger 400, model code LT-A400, represents a capable and reliable All-Terrain Vehicle (ATV) designed for a variety of demanding tasks and recreational pursuits. Produced across multiple model years from 2002 to 2007, this first-generation ATV is available in both 4x2 and 4x4 configurations, identified by chassis codes LT-A400 and LT-A400F respectively. The Eiger 400 is powered by a liquid-cooled, 376 cc single-cylinder engine featuring SOHC technology, delivering an estimated 23-25 horsepower and robust torque suitable for navigating challenging terrain. Its engineering quality is reflected in its durable construction, including a sturdy frame, selectable 4WD on applicable models, and efficient liquid cooling, all contributing to its reputation for dependability in its class. This comprehensive factory service manual provides in-depth guidance for the maintenance, repair, and servicing of the Suzuki Eiger 400 ATV. Covering all trim levels and model years from 2002 through 2007, the manual details essential procedures for engine mechanicals, transmission and drivetrain systems, electrical components, chassis and suspension, and braking systems. It includes routine maintenance schedules, detailed troubleshooting guides, step-by-step repair instructions, technical specifications, and critical wiring schematics. This resource is invaluable for owners and technicians seeking to ensure the optimal performance, longevity, and safety of their Eiger 400, enabling efficient and effective upkeep.