This manual covers Kohler Aegis engines, specifically models LH630, LH640, LH685, LH690, LH750, LH755, LH760, and LH775. These liquid-cooled, horizontal crankshaft engines are engineered for reliability and performance, featuring electronic fuel injection (EFI) for efficient operation. This documentation is designed to provide comprehensive support for these robust power units. The purpose of this factory service manual is to equip owners, mechanics, and technicians with the necessary information for maintenance, diagnosis, and repair. It includes detailed step-by-step instructions, exploded diagrams, and troubleshooting guidance for all major engine systems, including air, fuel, cooling, lubrication, EFI, and electrical components. This English-language resource ensures that users can effectively maintain and service their Kohler Aegis engines.