Briggs & Stratton 7.75 TP Professional Series Engine ES 25mm x 3-5/32 Vertical Shaft #121S07-0062 (11P905-0826) 25mm x 3-5/32" shaft, tapped 3/8"-24 with 1/4" keyway 12volt electric start, no alternator Ready Start, no choke- no priming. Fixed speed throttle design