This manual covers the 2019 Alterra 450, a versatile All-Terrain Vehicle (ATV) designed for recreational trail riding, light farm work, and general outdoor activities. Known for its ruggedness and value, the Alterra 450 is equipped with a 443cc, 4-stroke, single-cylinder EFI engine and a Continuously Variable Transmission (CVT) with selectable 2WD/4WD. Its robust chassis, hydraulic disc brakes, and comfortable ergonomics contribute to its reliable performance and rider safety. This mid-size utility ATV competes effectively in its segment, offering a balanced combination of power, handling, and durability for enthusiasts. This Service Repair Manual in English provides comprehensive guidance for maintaining and repairing the 2019 Alterra 450. It details diagnostic procedures, mechanical repairs for all major systems including the engine, drivetrain, suspension, and brakes, as well as electrical systems and body components. The manual includes essential maintenance schedules, fluid specifications, and troubleshooting guides, along with complete wiring diagrams. Its factory-level detail empowers both owners and professional technicians to perform routine maintenance, diagnose issues accurately, and undertake complex repairs, ensuring optimal vehicle performance and longevity.