Always has been hard to start first thing in the morning. It started on Sunday ran for a couple of swipes and stopped. Haven't been able to restart. Checked fuel pump, fuel filter, checked carb (needle valve, float, emptied bowl and refilled it), checked plugs. One time when checking plugs I had no spark. Checked other plug, no spark. Thought maybe parking brake button went bad, but spark started again. But still no start. Maybe bad sensor or something, PLEASE help. Thanks in advance.