This service repair workshop manual provides comprehensive information for the Yanmar 6LYA-UTE and 6LYA-STE engines. These internal combustion, inline 6-cylinder diesel engines are equipped with fuel injection equipment and a water cooling system, along with a reduction and reversing gear transmission. The manual details the engine's intake and exhaust systems, lubrication system, and electrical system. Yanmar engines are recognized for their robust engineering and reliability, making them a trusted choice for various applications. The purpose of this English-language manual is to guide owners, mechanics, and technicians through the maintenance, repair, and troubleshooting of the Yanmar 6LYA-UTE and 6LYA-STE engines. It includes step-by-step instructions for general servicing, complete disassembly procedures, and diagnostic guides. With hundreds of pages, accompanied by numerous photos and illustrations, this manual covers essential areas such as brake repair and suspension component replacement, ensuring the vehicle's optimal performance and longevity.