Briggs & Stratton 31R907-0006-G1 500cc 17.5 Gross HP Engine with 1-Inch by 3-5/32-Inch Length Crankshaft Tapped 7-16-20-Inch Cast iron cylinder sleeve and dual element air filter for extended engine life Float carburetor for consistent, easy starting Patented linear balancing system provides smoother performance 9 amp/electric & rewind back-up start CARB Compliant