This workshop repair manual covers the Kohler K91, K141, K161, and K181 gasoline engines. These single-cylinder, L-head (Valvular) air-cooled engines are known for their robust design and reliability across all production years. The K91 engine offers approximately 3.0 horsepower from its 340cc displacement, while the K141, K161, and K181 variants provide increased power outputs of approximately 5.0, 7.0, and 8.0 horsepower respectively, with corresponding displacements of 540cc, 700cc, and 820cc. These engines are engineered for demanding applications where consistent performance is essential. This comprehensive English-language manual provides extensive information for maintaining and repairing your Kohler engine. It details all workshop procedures, factory diagnostic information, electrical diagrams, torque settings, fluid capacities, and all maintenance procedures. Furthermore, it includes in-depth instructions for engine rebuilding and component replacement. The manual is designed to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of their Kohler K91, K141, K161, and K181 engines.