Originally Posted by chboone
If you do have the correct cap and have a vacuum in the tank the cause maybe the vapor recovery system is malfunctioning.
I have tested the problem as it may relate to the gas cap. I tried 3 different caps, and the problem remains the same. However, if I remove the cap, the generator runs fine. Further testing also shows that within 3 minutes after replacing the cap while both the RV and generator have been running without problems for 10 minutes or so, the generator will begin to starve for fuel and die.
It looks like you may have nailed it.