[MrFixr55]

Re the sparks, verify the condition of C33 and C34, the power line RFI filter caps on the generator. Verify the filters on the scope also if the scope is not grounded. If the caps in the generator are original, replace them with type Y safety caps or remove them. verify that there is no leakage from the power transformer or miswiring, solder splashes, grounding of one leg of the power cord, etc. Consider grounding the generator using a 3 wire cord. Use a 3 prong - 2 prong "Gozinto" (this gozinto that) if you must float the generator.

What is the frequency and voltage of the sine wave being displayed? is it 60 Hz, 400 HZ or something else? If it is 60 Hz and of high voltage, then it is from leakage and may be totally overriding the generator waveform.