remove the blower housing and pull off both kill wires.
Check that the fuel shut off solenoid is working.
Now go mow.
If the problem goes away then you have a problem with the electrical system.
Now put back one of the kill wires and tape the other terminal to prevent accidential grounding.
IF the mower plays up then you have a wiring problem
If it does not play up the diode between the coils is bad.