Why is riding lawnmower not restarting
Have a Craftsman Riding Lawnmower, Briggs Straton 21.0HP. Mowed almost all of 1.6 acres stopping twice over a few hours. Tried to restart 20 minutes later, nothing. Have replaced the following:
1. Installed new Starter
2. New Spark Plug
3. New Fuel Filter
4. New Safety Seat Switch
None of the above have helped.
Put gas in rag on breather intake and started a bit then stalled and would not restart. Changed Fuel Pump, took Carburetor off, cleaned inside/out with brake parts cleaner, still wouldn't start. Replaced Fuel Pump, started briefly, checked fuel regulator and was working properly.
Please reply with all troubleshooting tactics.