This manual covers Yamaha outboard engines from the 2004 model year, encompassing a wide range of models from 2.5 HP to 300 HP. Yamaha is renowned for its engineering quality and reliability, and this service manual provides comprehensive details to ensure your outboard operates at peak performance. It is designed for owners and technicians who value precision and durability in marine propulsion systems, offering in-depth information for a variety of specific outboard models. The purpose of this manual is to provide detailed instructions for the maintenance, repair, and troubleshooting of your Yamaha outboard engine. It includes general information, specifications, procedures for periodic inspections and adjustments, and in-depth guidance on the fuel system, power unit, lower unit, and electrical systems. With step-by-step instructions and high-quality diagrams, this manual is an essential resource for anyone looking to perform their own repairs and maintenance, saving time and money while ensuring the longevity of their Yamaha outboard.