This manual covers the Mercury Mariner, a 4-stroke outboard engine with 40 HP, manufactured between 1999 and 2003. Designed for reliable performance, the Mariner is engineered to meet the demands of various marine applications. Its robust construction and efficient power delivery make it a dependable choice for boaters seeking consistent operation on the water. This comprehensive service manual provides detailed information essential for the maintenance and repair of your Mercury Mariner. It includes step-by-step procedures for routine servicing, troubleshooting common issues, and understanding technical specifications. By following the guidelines within this manual, owners and technicians can ensure the longevity and optimal performance of the engine.