This manual covers Yamaha 25BMH and 30HMH outboard motors. These engines are known for their robust engineering and reliable performance, making them suitable for a wide range of boating applications. While specific production years are not detailed, this guide is designed to assist owners and technicians with the maintenance and repair of applicable models. The 25BMH offers 25 horsepower and the 30HMH delivers 30 horsepower, both typically featuring 2-stroke configurations and carburetor-based fuel systems, ensuring efficient operation for their intended use. The purpose of this comprehensive Factory Service/Repair/Workshop Manual is to provide detailed guidance for the upkeep and servicing of your Yamaha outboard motor. It includes step-by-step instructions, highly detailed exploded pictures, and diagrams to facilitate understanding of all maintenance, service, diagnosis, and repair procedures. Key areas covered include general information, specifications, periodic checks and adjustments, fuel system, power unit, lower unit, bracket unit, electrical systems, and trouble analysis. This manual is an essential resource for ensuring the longevity and optimal performance of your Yamaha 25BMH or 30HMH.