This workshop service repair manual covers the Briggs & Stratton Vanguard Twin Cylinder OHV Engine, designed for robust performance and reliability. While specific production years are not detailed, this engine series, including codes like 351400, 380400, 351700, and 380700, features an Overhead Valve (OHV) design and mechanical governor system. Its twin-cylinder configuration and carbureted fuel delivery are engineered for efficient operation across various applications. This comprehensive English-language manual is intended for DIY persons, professional technicians, mechanics, and workshops. It provides detailed guidance on safety, maintenance, adjustments, troubleshooting, and repair procedures. Key sections cover engine disassembly, fuel and lubrication systems, ignition, starters, and internal components such as crankshafts, pistons, and connecting rods. The manual includes clear, step-by-step instructions, zoomable illustrations, exploded views, and component breakdowns to facilitate accurate diagnosis, service, restoration, and rebuilding of the engine.