What type of fuel does the genset and MH use? Gasoline or diesel? I am assuming gasoline, but if it is a diesel, don't take any advice for a gasser.
The first thing that comes to mind... is the fuel tank near the quarter tank level? The port of the generator for fuel is a quarter tank, so if it gets lower than that, the engine will still run, but the genset would run dry.
If it were a gasoline generator and gas engine, I'd probably dump some Berryman's B-12 or another additive in the tank just to see about helping with varnish on the carb. If the rig sits around for a while and the generator is unused, I'd also consider tossing a fuel preservative in the tank on a fillup just to prevent varnish from happening.