This Service Repair Manual provides comprehensive guidance for the Mercury Mariner 25hp 4-stroke Bigfoot outboard motor. Engineered for reliability and performance, this outboard motor is designed to meet the demands of various marine applications. Its robust construction and advanced 4-stroke technology ensure efficient operation and durability. The Bigfoot series is known for its enhanced torque and thrust, making it ideal for heavier loads and challenging water conditions. This manual covers all essential aspects of maintaining and repairing your Mercury Mariner outboard motor. It includes detailed procedures for routine maintenance, such as lubrication and tuning, as well as in-depth technical guidance for gearcase service and tilt and trim systems. With clear, step-by-step instructions, zoomable illustrations, and exploded views, this resource empowers owners and technicians to perform diagnostics, troubleshooting, and repairs effectively, ensuring the longevity and optimal performance of the engine.