Briggs & Stratton 9P702-0116-F1 550e Series 140CC Engine Tapped with 3/8-24-Inch 3/16-Keyway and 7/8-Inch Diameter Optional Ready Start starting system with no prime, no choke, no worries, just pull for power Dual-sealing air cleaner for improved debris resistance and longer life Lightest engine in its class by 30% for easier maneuverability Acoustically-engineered muffler for quiet operation and excellent tonal quality Less vibration for more user comfort and enhanced engine life