This Service Repair Manual covers the YANMAR SY Series Marine Engine, including models 6SY-STP2, 6SY655, and 8SY-STP. Engineered for reliability and performance, the SY Series represents YANMAR's commitment to quality in marine propulsion. This manual is designed to provide comprehensive information for the service, maintenance, and troubleshooting of these engines, ensuring optimal operation and longevity. The scope of this manual encompasses complete disassembly of the machine, offering step-by-step instructions and highly detailed exploded pictures and diagrams. It is intended for use by owners, mechanics, and technicians alike, providing the same level of detail found in professional service shops. This English-language manual is an essential resource for maintaining and repairing your YANMAR SY Series Marine Engine.