Was the rv parked through the winter with 25 gallons of fuel? If so, was the fuel stabilized with an enzyme fuel treatment https://www.goldeagle.com/tips-tools...ars-need-use/?
If not, then contamination is likely.
Check if the gasoline is old or contaminated. You can do this by removing representative fuel from the fuel tank into a clear glass container. In another container, pour some fresh gasoline and compare.
If the rv still operates run the engine until the fuel is down and change the fuel filter and check the fuel lines.
If you remove the fuel into appropriate storage containers dispose it at a hazardous disposal site.