This service repair manual covers Yamaha, Mercury, and Mariner 4-stroke outboard engines manufactured between 1995 and 2004, encompassing a wide range of models from 2.5 to 225 horsepower. These engines are recognized for their robust engineering and reliable performance, making them a popular choice for various marine applications. This comprehensive guide provides detailed information to ensure the optimal operation and longevity of your outboard engine. The purpose of this manual is to provide owners, technicians, and mechanics with the necessary information for the maintenance, repair, and troubleshooting of these outboard engines. It includes extensive coverage of tools and techniques, tune-up procedures, timing and adjustments, fuel and electrical ignition systems, and detailed repair instructions for various components such as the lower unit and gear case. With step-by-step operations, real photo illustrations, and diagrams, this manual serves as an indispensable resource for keeping your engine in peak condition.