The YANMAR 6LY2 Series Diesel Engine, encompassing models 6LY2-STE, 6LY2A-STP, and 6LYA-STP, represents a robust line of marine diesel engines designed for demanding maritime applications. These 6-cylinder, inline, turbocharged and intercooled engines deliver a power output range of 440-480 horsepower (328-358 kW) from their 6.5-liter displacement. Engineered for reliability and performance in marine environments, the 6LY2 Series features indirect raw water cooling and is built to YANMAR's high standards for durability and operational efficiency. This Workshop Repair Manual provides comprehensive guidance for the YANMAR 6LY2 Series Diesel Engine. It covers essential areas including general information, care and safety, routine maintenance, systems description, fault finding, and detailed procedures for the fuel, cooling, lubrication, electrical, induction, and exhaust systems, as well as the base engine. With step-by-step instructions and visual aids such as photos and illustrations, this manual is an indispensable resource for owners, mechanics, and technicians seeking to perform servicing, preventative maintenance, and troubleshooting to ensure optimal engine performance and longevity.