Mower Won't Start

I have a Sears Craftsman Self-Propelled 22" mower. It has a Briggs&Stratton 700 Series, 190cc engine. I've owned the mower for 4 years and it has always started with just a pull or two on the starter handle. I tried to start it for one final cut a couple of weeks ago and could not get it to start. Pulled the plug and checked the gap, it was ok. Checked the filter, it was a little dirty but not bad. Took the filter off and sprayed starter fluid right into the intake. It would try to start, sputter and then quit. Did this several times, no success. Also I've never let gas sit in the mower over the winter. I've always run the gas out before storing. I also use fresh gas each season.
Looking for help and ideas as to what I can do next to get the mower to start.
Thanks for any help!

Mower Won't Start