[gearhead]

My first thought is it would have a diaphragm type fuel pump working off crankcase pulses, assuming the gas tank is relatively close. I would look for an online repair manual to be sure about what type pump. If its 12volt you may be damaging it.
If you know of a full service RV shop maybe visit them and ask.
I've found that having an independent shop doing repairs is much better than the dealer. Find one that is an Onan authorized warranty shop. Cultivate a relationship with an independent shop. Most dealers seem to not want to do repairs anyway.