Briggs & Stratton 12V352-0015-F1 Horizontal Vanguard Engine with 6:1 Gear Reduction, 203cc, 6.5 Gross Horsepower, 3/4″ x 1-13/16″ Crankshaft, 5/16″-24 Drilled & Tapped, 3/16″ Keyway, Recoil Start, Counter-Clockwise Rotation