first buy one lol. now remove the tank and carb from the engine. put it on a bench, now remove the screws holding the carb to the tank and remove the carb, the diaphragm and gasket will probs come off with the carb, clean the tank wher the carb meets it. now peel off the gasket/diaph from the carb noting which one goes on which side, and where the spring is. now clean off the carb, then making shaw the spring is where it came from, reassemble. combine this repair with a new plug and it will be like a new mower. from my experience this fixes 9 out of 10 briggs.
Andy Lee
June 2009