Going to cut the grass or the first time this year. Before winter I drained the gas and pulled the cup off the bottom of the carb and emptied all fuel. I put in some old gas and it started and ran for a few minutes and died. I got new gas filled it up. Pulled the carb off and sprayed it with carb cleaner. It would not start. I pulled the plug. And cleaned it. I checked for spark and there is one but not blue more yellow. Any ideas on the spark or what else it could be? I need to mow the yard so I can go turkey hunting.