More than likely a blown piston. Pretty common on those if the waterpump update has not been done. You cannot see the pistons through the exhaust on that motor.
The flywheel is bent it is junk now. That's what happens when you hit them with a sledge. You cannot have 120 volts with a 12 volt battery. Have you checked the lanyard switch? Ignition switch?
What Rev sensor? Any over Rev protection on that motor would kick in at around 5300 rpm. Get a factory manual and read it front to back. Or find a dealer familiar with the 2+2 motor. Dog clutch has nothing to do with your problem. Get a manual
