This document provides comprehensive information for the Mercury Mariner outboard motor, produced between 2000 and 2005. Designed for reliable performance, these early 2000s models are known for their robust engineering and dependable operation. This particular manual focuses on the 90 HP variant, featuring a 4-stroke, water-cooled engine with a displacement of approximately 1.5 liters, available in 3 or 4-cylinder configurations. It utilizes unleaded gasoline, a CDI ignition system, and a Forward-Neutral-Reverse gear case, making it suitable for a variety of boating applications. This Factory Service Repair Manual is your essential guide to understanding, maintaining, and repairing your Mercury Mariner outboard. It covers critical aspects including detailed maintenance procedures for routine service, such as oil changes and spark plug replacement, as well as component-specific tasks like water pump impeller service. Technical specifications, troubleshooting guidance, and electrical system details are also included. By following the instructions and recommendations within this manual, owners and technicians can ensure optimal performance, longevity, and safe operation of their Mercury Mariner motor.