Ya, at least on our 6.5, had to pull the generator to access the regulator.
I do not know access on yours.
Once out, should be easy to identify the regulator and find an overhaul kit.
The problem with ours was the orientation of this very good, widely used regulator-- laying on "its side". If installed vertically like in propane powered vehicles the longer hydrocarbon chain contaminants just pass on through and are burned. Installed horizontally, they just collect. Again, this is on the older series liquid LP Onans-- yours may be completely different.