This operation manual pertains to the Yanmar SKE Series marine diesel engines, designed for reliable marine propulsion. These engines are engineered to deliver robust performance and efficiency in demanding marine environments, reflecting Yanmar's commitment to quality and durability. This manual provides comprehensive guidance for the operation and maintenance of your SKE Series engine, ensuring its optimal function and longevity. The purpose of this manual is to serve as a definitive resource for all aspects of your Yanmar SKE Series marine diesel engine. It covers essential operational procedures, including pre-use checks, preparation, starting, during-operation monitoring, and stopping. Furthermore, detailed maintenance information, such as air venting and periodical DIY checks, is provided, along with a scheduled maintenance schedule. This guide is intended for owners, operators, and technicians to facilitate proper usage and upkeep, ensuring the continued performance and reliability of the engine.