This workshop service manual covers the Mercury Mariner 40 HP outboard motor, a 4-cylinder, 2-stroke engine designed for reliable performance on the water. With a 700cc displacement and carbureted fuel induction, this outboard motor is engineered for efficiency and power. Its water-cooled system and CDI ignition ensure consistent operation in various conditions, making it a robust choice for recreational and professional marine applications. This comprehensive manual provides detailed information for technicians responsible for the maintenance and repair of the Mercury Mariner 40 HP outboard motor. It includes essential procedures for lubrication, service schedules for annual maintenance, spark plug replacement, and gearcase lube changes, along with specifications for its 2.00:1 gear ratio and outboard drive system. By following the guidelines within this manual, users can ensure the longevity and optimal performance of their Mercury Mariner outboard motor.