Briggs & Stratton 44Q777-3137-G5 724cc 27.0 Gross HP EXtended Life Series 1-Inch Diameter X 3-5/32-Inch Length Crankshaft, Keyway, Tapped 7/16-20 (Discontinued by Manufacturer) CARB compliant Overhead valve design for cooler operation and longer valve life Adanced debris management system with a dual seal, cartridge-style air filter provides maximum protection and extends engine life Full pressure lubrication with oil cooler and spin-on oil filter assures controlled lubrication for extended life CARB Compliant