bought this mower new last fall... used about a dozen times. Sta-bil ized the fuel last winter. Started up and ran fine for two or three mowings, and now won't start, despite it "almost" starting on occasion. It's one of those 190cc Briggs & Stratton "no choke / no throttle" engines. Starting fluid seems to have no effect.
Replace the spark plug. Some of the newer engines have a special plug that requires a .020 gap and has a habit of fouling out. Since 2012 they have been using a special plug only available from Briggs dealers ( I know) and will cause a misfire if the wrong gap and plug is used.
