This service repair manual provides comprehensive guidance for the YANMAR MP Series Diesel Engine Fuel System, covering models 3MP2, 4MP2, and 4MP4. These diesel engines are engineered for robust performance and reliability, designed for demanding applications requiring efficient fuel system operation. The manual addresses specific engine models including 3MP2 (3TNV82A/84(T)/88), 4MP2 (4TNV84(T)/88), and 4MP4 (4TNV94/98(T)106(T)), ensuring precise service for each variant. The purpose of this manual is to serve as an indispensable resource for maintaining and repairing the YANMAR MP Series diesel engines. It details essential procedures such as disassembly and assembly, fuel injection pump and governor system service, fuel charge pump, injection nozzle maintenance, pump timing, cleaning, inspection, and injection testing. Technical specifications, tightening torques, and lists of required measuring instruments and service tools are included, along with troubleshooting guidance and clear illustrations featuring exploded views. This manual is designed to assist owners, mechanics, and technicians in performing accurate and effective service.