This manual covers the Cummins M11 Series Celect Engine, designed for robust performance and reliability in demanding applications. Engineered with precision, these engines are built to deliver consistent power and efficiency, making them a trusted choice for various heavy-duty uses. The comprehensive nature of this guide reflects the quality and advanced technology integrated into the M11 Series, ensuring optimal operation and longevity. The purpose of this manual is to provide detailed information for the maintenance, repair, and servicing of the Cummins M11 Series Celect Engine. It includes essential sections such as engine identification, disassembly and assembly procedures, fuel and lubrication systems, cooling, electrical equipment, and engine testing. With step-by-step instructions, technical specifications, diagrams, and illustrations, this resource is invaluable for owners, technicians, and mechanics seeking to perform tune-ups, regular maintenance, or complex repairs.