This manual covers the Mercury Mariner Marathon outboard motor, a powerful and reliable marine propulsion system designed for a variety of watercraft. Engineered for performance and durability, this 25 HP outboard motor is built to provide exceptional service in demanding aquatic environments. Its robust construction and efficient design ensure consistent power delivery and smooth operation, making it an ideal choice for recreational boating, fishing, and other marine activities. The Mariner Marathon series represents a commitment to quality and user satisfaction, offering dependable performance that owners can count on. The purpose of this Factory Service Repair Manual is to provide comprehensive guidance for the maintenance, repair, and servicing of your Mercury Mariner Marathon outboard motor. It details essential procedures, technical specifications, troubleshooting steps, and safety precautions necessary to keep the motor in optimal working condition. This manual is an indispensable resource for owners, technicians, and mechanics, offering the in-depth information required for effective upkeep and repair, ensuring the longevity and peak performance of the 25 HP engine.