I just bought a 98' Itsaca, Spirit, 22 footer. The idle when the generator runs is not constant. The spark plug has been changed, gas has been drained, and the idle is still up and down. When the appliances are on it seems to run the best, but when I shut some of them off, the idle on the generator starts going up and down and as if it wants to shut off. The guy I bought it from says that is just they way it runs since it is small, 2.3 KW.