from smokestack
The KW rating is usually limited by the engines power rating. With normal 3 phase generators, there is usually a 25 percent excess of copper and iron to allow the extra reactive current for motor operation, and some additional starting current. After all the reason 3 phase power is used is mainly for motors. Normally operating one of these single phase at the same voltage requires derating by 1.732 of the kva maximum current; the limit being coil current. By reconnecting the coils in double-delta, or low zig zag, the voltage becomes 120/240 and the coils limit the output to 66% of name plate rating. To make full use of the engine, our uncle having unlimited recources has wound his genetators with 50% larger coils than normally required, and thereby allowing full KW output on single phase operation. This also requires 50%extra exciter capacity. Hence the 52 amp at 120 volt capability of your machine. The military under rates their engines at least 20% but I'm not sure if the fuel is cut back. You can tell by loading it until the frequency begins to fall rapidly with load addition and the fuel arm is against the stop. If it belches black it is full fuel, if none or very light smoke, it is set back and you can set it up by adjusting the fuel stop screw. This same unit is rated a 6 Kw Civy. I dont believe given the oversize windings that you can hurt one of these units other than the obvious short circuit or low speed operation. These units also use magnetic amplifier exciter field power so they will start motors very well. But you must be carefull about under frequency operation. The high current combined with reduced cooling can overheat the windings, the field has a breaker so it should be OK. In answer to your question, there would be no benefit to any electrical chances in this machine.
maybe this link will help.
http://www.smokstak.com/forum/showthread.php?t=16340