This workshop service repair manual covers Kohler K91, K141, K161, and K181 series single-cylinder, air-cooled, 4-stroke gasoline engines. These engines, designed for various applications, are known for their robust construction and reliable performance. The K91 and K141 models offer approximately 7 HP with a displacement of 14.1 cu in (231 cc), while the K161 provides approximately 8 HP with a 16.1 cu in (264 cc) displacement. The K181 model delivers approximately 9 HP from its 18.1 cu in (297 cc) displacement. This manual is intended to provide comprehensive information for maintaining and repairing these dependable engines. The purpose of this English-language manual is to offer detailed guidance for all aspects of engine servicing. It includes step-by-step instructions for DIY servicing, teardowns, repairs, overhauls, and adjustments, supported by exploded views, diagrams, illustrations, and pictures. Owners, mechanics, and technicians will find detailed technical information, specifications, and accurate adjustment procedures to ensure optimal engine performance and longevity. This resource is designed to be an indispensable tool for anyone working with these Kohler engine models.