This manual covers the Yanmar 4LHA Series Marine Diesel Engines, including models such as the 4LHA-STE, 4LHA-STZE, 4LHA-STP, 4LHA-STZP, 4LHA-DTE, 4LHA-DTZE, 4LHA-DTP, 4LHA-DTZP, 4LHA-HTE, 4LHA-HTZE, 4LHA-HTP, and 4LHA-HTZP. These inline 4-cylinder engines feature a 2.377 L displacement, direct injection fuel systems, and are turbocharged, with intercooling for 'Z' models. Designed for marine applications, they are known for their compact design, robust construction, and reliable performance, typically delivering between 160 and 200 horsepower. This factory service repair manual provides comprehensive guidance for owners, mechanics, and technicians. It details essential maintenance procedures, including engine oil capacity and recommended service intervals, fuel filter replacement, and impeller maintenance. The manual also offers a thorough troubleshooting guide for common issues and diagnostics, along with technical specifications for engine configuration, aspiration, cooling systems, and transmission options. This resource is designed to ensure the optimal performance and longevity of your Yanmar 4LHA Series engine.