Ben, thanks for that info, as I said, you will get differing replies !!
As for the genny you have, I would strongly advise against using it at all, except in the case that you remove the battery from the van and charge it on its own.
It really is not worth the risk and cost to try and run the 2 stroke generator through the van systems.
They need very regular servicing and as it is unlikely to be a voltage regulated with sine wave technology unit, if it falters or starts to run out of fuel it WILL put somewhere around 290v or more into the van!! and the electronics in the van, especially your distribution box and charger unit will get damaged, probably irrepairably.