c. 1910s to 1920s Associated 4 HP Engine

 This engine (serial #413204) was made by the Associated Manufacturers Company in Waterloo, Iowa. Initially called the "Farm Hand," the Associated 4 HP engine became the "Four Mule Team" portable engine in 1915. Weighing about 1,000 pounds, this engine was rated at 400 RPM. It cost $130 with the magneto.

Notes

C. H. Wendel. American Gasoline Engines Since 1872. Edited by George H. Dammann. Sarasota, FL: Crestline Publishing Co., 1983, p. 35.