This workshop service manual covers the Mercury Mariner Marathon, an outboard motor designed for marine propulsion. Featuring a 3.0L gasoline engine and a water-cooled system, this model is part of the Marathon Series. Its robust engineering is built for reliability in demanding marine environments, offering dependable performance for various watercraft. This comprehensive manual provides essential information for maintaining and repairing the Mercury Mariner Marathon. It details procedures for scheduled maintenance, lubrication, and covers the electrical system, including its CDI ignition. The manual serves as a vital resource for owners, mechanics, and technicians, ensuring the longevity and optimal performance of the outboard motor.