Briggs Stratton 19N132-0051-F1 306cc 1450 Series Horizontal Engine, 3/4-inch x 2.51-inch Crankshaft, 3/16-inch Key, 3/8-24 Tapped, Direct Replacement for 20S232-0063-F1.
Briggs Stratton 25T237-0045-F1 420cc 21.0 Torque 2100 Series Gas Engine, 1-inch x 3-31/64-inch Crankshaft, Tapped 7/16-20, 1/4-inch Keyway, Electric Start.