Hello, thanks for allowing me into this forum. I have a Yard Machines lawn tractor that I purchased through Home Depot about four years ago. I have a 1 acre yard that I cut about once per week. Years 1-3 were great. No issues. I always run non-ethanol fuel. I change the oil, oil filter, air filter, spark plug regularly. For the last few months the tractor starts just fine and runs great for about 20 minutes. Then the tractor will sputter a few times and then cut out. It will then not re-start easily for an hour or so. I replaced the battery last year and again today but the problem still exists. It starts and runs great for 15-20 minutes then sputters and stops. Any help would be GREATLY APPRECIATED. Thanks Joe