This manual covers the D3 Marine Engine, Generation B, a robust 5-cylinder marine diesel engine designed for a variety of maritime applications. Known for its engineering quality and reliability, the D3 series offers multiple power variants, including the D3-110i-B, D3-130i-B, D3-160i-B, D3-190i-B, D3-130A-B, D3-160A-B, and D3-190A-B. The 'i' designation signifies an inboard sterndrive configuration, while 'A' denotes an auxiliary drive suitable for sailboats, highlighting the engine's versatility. This comprehensive Service Repair Workshop Manual in English provides essential information for technicians and owners alike. It details a wide range of topics, including safety guidelines, general engine information, step-by-step repair instructions, the use of special tools, engine overhaul procedures, disassembly and assembly processes, component-specific repair guidance for critical parts like the engine block, cylinder head, crankshaft, pistons, lubrication, fuel, cooling, and exhaust systems, as well as fault tracing and electrical system diagnostics. The manual's detailed content, supported by exploded views, pictures, and diagrams, ensures effective maintenance and repair of the D3 Marine Engine.