Right now generator is at 50 Hz, its designed freq, but I've also adjusted the freq to 60 Hz, while down adjusting the total voltage. The odd voltage ratios continue without change. Not sure if I understand your second question. With the two windings tied to neutral, each measures about 165 v, while across the outer wires, total is 240 v. I've tried connecting a simple incandescent bulb to each line, and it is very, very bright--as about to burn out--confirming the measured RMS ac voltage--much higher than the expected 120 v. I've also connected a 240 v water heater across the outer leads, with significant load on the diesel engine, and the coil heats up appropriately. I've had a couple of engineers suggest the only solution will be to assume the generator is a "delta" unit, and use a transformer with a secondary with center tap, and so get around the high voltages when neutral is used.