This workshop service repair manual covers the International Harvester (IH) Cadet 81, a compact utility tractor designed for property maintenance and light agricultural tasks. Produced likely in the late 1960s to early 1970s, the IH Cadet 81 is known for its robust construction and reliability, typical of International Harvester's legacy in agricultural machinery. It competed with other compact tractors of its era and was built for durability, featuring a 2-cylinder, air-cooled gasoline engine and a manual gearbox. This tractor represents a practical and dependable option for homeowners and small farm operations. This comprehensive manual provides detailed service and repair information for the IH Cadet 81 tractor. It covers all major systems, including the engine, fuel, cooling, ignition, electrical, transmission, hydraulics, steering, and brakes. Within its pages, you will find routine maintenance procedures, troubleshooting guides, complete engine and transmission overhaul instructions, and guidance on repairing hydraulic and electrical components. Technical specifications, adjustment procedures, and identification of special tools are also included, ensuring that owners, mechanics, and technicians have the necessary resources to maintain and repair this reliable piece of equipment effectively.