This workshop manual covers the Westerbeke FOUR-230 and SIX-346 Diesel engines. These diesel engines are engineered for reliability and performance, with the FOUR-230 featuring a 3.78L displacement and the SIX-346 offering a larger 5.65L displacement. Both models are designed for demanding applications, emphasizing robust construction and efficient operation. This comprehensive service repair manual in English provides detailed information for maintaining and repairing your Westerbeke diesel engines. It includes step-by-step instructions, detailed illustrations, diagrams, and pictures for various procedures such as engine overhaul, disassembly, assembly, and specific system repairs including fuel, cooling, and marine transmission. The manual also offers troubleshooting guidance and essential specifications, including tightening torques, making it an indispensable resource for DIY enthusiasts and experienced mechanics alike.