The YANMAR 4TNE94/4TNE98/4TNE106 series represents a line of reliable diesel engines designed for demanding applications, primarily in forklifts. These engines feature a SOHC valve mechanism, liquid cooling, and direct injection fuel systems. Variants include naturally aspirated versions for the 4TNE94 and 4TNE98, and a turbocharged option for the 4TNE106T, offering displacements of 2.3 L, 3.3 L, and 3.9 L respectively. Their robust engineering ensures consistent performance and durability in industrial environments. This workshop and service manual provides comprehensive guidance for the maintenance and repair of the YANMAR 4TNE94/4TNE98/4TNE106 engines. It covers essential areas including general information, troubleshooting, inspection and adjustment procedures, and detailed breakdowns of the engine body, lubrication system, cooling system, fuel injection system, governor, turbocharger (where applicable), starting motor, and alternator. The manual is intended to assist owners, mechanics, and technicians in effectively maintaining the operational integrity and longevity of these engines.