This Service Repair Workshop Manual covers the YANMAR 12LAK-STE2, 12LAKM-STE2, and 16LAK-STE1 marine diesel engines. These engines are engineered for demanding marine applications, offering robust performance and reliability. This manual is designed to provide comprehensive guidance for the servicing, repair, and troubleshooting of these specific diesel engine models, ensuring optimal operation and longevity. The purpose of this manual is to serve as a definitive resource for all maintenance and repair needs. It details a wide array of procedures, including step-by-step instructions, exploded diagrams, and essential technical specifications. Owners, mechanics, and technicians will find this English-language guide invaluable for performing all repairs, routine servicing, and diagnostic work, ensuring the YANMAR marine diesel engines remain in peak condition.