I have a Toro zero turn mower model 74203 serial 990223 that stalls a few seconds after it starts. I replaced fuel filter, problem persisted. I then rebuilt and cleaned carb and problem persisted. I then replaced the carb completely and problem persisted. So then I changed out the fuel pump but again it didn't help. Mower has recently had a full tune up with new plugs and filters. I have no idea what to do next. Any direction would be greatly appreciated.