Brute with B&S 7.25 EXi Series Won't Start

We purchased a Brute walk behind mower with B&S 7.25 EXi Series mower Saturday, 5/7/16. Filled with fresh gas purchased less than 2 hours before and correct amount of oil before first use. Fired up first try and used less then 30 minutes and put away in shed.

My wife went to use it a few days later and it fired up second time. The motor just would not restart after being stopped briefly. Tried usual suggested trouble shooting fixes, like check/replacing air filter. Also checked/replaced spark plug. The carburettor smells like it's getting gas. Tried a small shot of quick start, and other then backfiring a few times not much else happened. The pull cord seems to resist an unusual amount. When it does pull, motor turns over and does not start. After the spark plug which was installed in the mower when it was first run was removed and inspected it looked blackened.

Again I put it together and set it up according to the included instructions letter for letter. I'm not very happy with this product. We spent $300.00+ on a lawn mower that now flatly refuses to start after being used less than 45 minutes.

Does anyone have any suggestions?

Best Regards

Joe D

Brute with B&S 7.25 EXi Series Won't Start