Onan 2500 LP Generator Acting Up (again)

While this most likely is not your problem, I am putting this out there in the hopes of helping someone else. When I purchased my 2009 Lance 845 the Onan RV QG 2500LP generator with 40 hours total run time would start very hard and would not run smooth. I pulled it out of the camper and started playing with and figured out if I shut the propane bottle almost all the way off, it would smooth right out. I tested the gas pressure and it was right where it was suppose to be. I checked out all of the fuel system and I could not come up with anything wrong. Then one day I was looking through the parts listing I noticed it showed a little door that covered the air filter access opening and that made me wonder, as mine was not there (up until that point I did not even know there was suppose to be a cover there) Anyway to test it out I covered the opening with duct tape and the generator started and ran perfect. Well evidently that door has to be there as the air filter area sits in the cooling air flow and the air flows acts as a sort of supercharger and leans the mixture down just enough to make it run properly. I was able to order a new door from Onan.

I wasted a ton of time trying to figure out that simple problem.