Briggs & Stratton Lawn Mower Engine Problem

My lawn mower was sputtering for a while then died and now it won't start. I have changed the oil, air filter, and cleaned the carburetor. It has a Briggs & Stratton 124T02-0161-B1 engine on it. I have a link to a video of my trying to start it up, which I thought might be useful.

Problems Starting Briggs & Stratton Engine on Lawn Mower - YouTube

Thank you for your help.

 

First I would remove the spark plug and re-connect it's wire. Place the spark plug so the metal hex part or tip (where it sparks) is touching bare metal on the engine. Give the cord a good hard pull while looking at the plug. Do you see it spark?

If you do not see a spark you could have a bad spark plug, coil or spark plug wire. If you do see a spark then put a teaspoon of gas into the cylinder through the spark plug hole and reinstall the spark plug. Give it 5 or 10 good pulls on the cord. Does is fire or run for a second? If it does sputter or run a bit you probably have a carburetor problem and I would remove it from the engine, disassemble and give it a thorough cleaning.