Briggs and Stratton 28N707. The Briggs and Stratton 28N707 is a 465 cc (28.38 cu·in) single-cylinder air-cooled four-stroke internal combustion gasoline engine, manufactured by Briggs and Stratton. The B&S 28N707 engine has an OHV (overhed valve) design and a vertical PTO shaft. This engine is equipped with float type carburetor and an Messages. 666. Aug 21, 2013 / Adjust Valves on 19.5 B&S Single Model# 31P6770140B1. #3. Finally got the oil pan lined up with the governor, camshaft, oil pump shaft after several tries only to find it was in a bind due to the pressure on the crankshaft pushing it into the bind. Had to remove the oil pump cover to visually align the drive shaft XOWGzM.