The original Briggs and Stratton engine was a
2.4 liter, single cylinder, OHV, 4-stroke design with a bore of 70 mm and stroke of 90 mm. This engine had a compression ratio of
3.3:1 and developed about 80 HP. The later 3-cylinder models used in lawn mowers had a bore of 58 mm and a stroke of 81 mm.