This workshop service and repair manual covers the Yanmar SY Series marine engines, specifically the 6SY and 8SY models. These engines are engineered for reliability and performance in marine applications, offering robust solutions for various operational needs. The manual provides detailed information for maintaining and repairing these high-quality marine propulsion units, ensuring their continued optimal function. This comprehensive English-language manual, spanning 306 pages, offers step-by-step instructions and technical details for a wide range of maintenance and repair procedures. It includes sections on safety, general service information, periodic maintenance, and in-depth coverage of the engine, fuel system, cooling system, lubrication, turbocharger, starter motor, alternator, and EMS. Troubleshooting guidance and numerous illustrations, including exploded diagrams and photos, are provided to assist owners, mechanics, and technicians in effectively servicing their Yanmar SY Series engines.