I acquired this engine some time ago. This is a Keystone 5 hp, 2-cycle vertical engine, serial no. 0100. The flywheels are 3 inches by 20-1/2 inches. The ignition system is an Atwater Kent timer, patent 1901. It took me five to six years to find a coil. This coil has five binding posts and has to have special wire for it. This engine was built by Rockwell Mfg. Co. in West Chester, Pennsylvania. There is a good picture in American Gas Engines Since 1872 on page 431. It’s a cutaway showing the intricate balancing system.
Howard L. Abrahamson, Duluth, Minnesota