Check fuel flow out of fuel pump. Check for functional operation of anti-after fire carburetor solenoid. Pull fuel line after fuel pump back to tank, remove cap, and blow back through to tank.
I do not have any service information but those symptoms are typical of a bad electric connection or in particular with JD's a failing relay or relay holder
For starters remove the kill wires form he magneto and see if the problem goes away
This will isolate the problem to safety switches in the mower or engine failures
