A-B1592828-AI ALTERNATOROne New Aftermarket Replacement Alternator Fits Briggs and Stratton (Fits Briggs & Fits Stratton) Engines This aftermarket replacement alternator fits a wide range of Fits Briggs and Stratton small engines used in lawn tractors, lawn mowers, and outdoor power equipment. As a complete alternator assembly, it converts mechanical energy into electrical energy to maintain battery charge and power the ignition system and accessories while the engine runs.