This manual covers the Yanmar 4TNV98-YTBL and 4TNV106T-XTBL engine models, designed for industrial and construction equipment applications. Specifically, these engines are found in Gehl CTL60/80 track loaders and Mustang MTL16/25 track loaders, respectively. Yanmar engines are recognized for their robust engineering and reliability, ensuring consistent performance in demanding operational environments. This parts manual provides detailed information to identify and source components for these powerful engines. The purpose of this English-language Parts Manual is to provide comprehensive guidance for identifying and ordering replacement parts for the specified Yanmar engines. It features easy-to-read text, high-quality diagrams, and detailed exploded views to assist both do-it-yourself users and experienced mechanics. The manual covers a wide range of components, including the cylinder block, cylinder head, fuel system, lubrication system, cooling system, and more. Its detailed illustrations and comprehensive coverage facilitate efficient maintenance and repair, ensuring the longevity and optimal functioning of your equipment.