When doing the initial intake testing, we found that the 120 Volt generator was creating 224 Volts AC and the engine was over-revving at 5500 RPMs.
The initial suspicion was a failed governor system. Upon closer inspection inside the engine of the crankshaft and governor, we found that the crankshaft has been weakened by excessive heat and the connecting rod bearing is failing as well.
Final problem: Locked throttle plate in the carburetor. Failed Pilot Valve.