Hi Ski and Joe,
You're correct, it is two separate 120 volt 'legs' connected together to produce 240 VAC. I read 120 volts on each generator, but not 240 volts across both. I'm going to split them up and put a 24 volt transformer on each output and connect that up to the scope. I suspect that when I split them I'm going to find out that only one is actually putting out 120 volts, and that it was feeding the other one through the transformer. If the other one is putting out less voltage out of phase that would explain it.

I have seen a lot of PTO generators before that produce 240 or 208 volts, and then drop this to 120 through a transformer, they are pretty common on farms in the U.S. but I've never seen one like mine before.

I'll let you know what I find next!
Thanks,
Jerry