We have had Onans on the last 5 MHs and yes their have been times when they didn't seem to want to settle down and run evenly. Doubt if it was anything we did to cause it. I always figured it more or less a combination of the quality of gas and the load. Also, once I changed the inline gas filter, another thing I had fuel line problems. Spent a small fortune trying to cure that one, even changing the fuel pump and having the full 75 gal tank drained and flushed. It was a collapsed fuel line about a foot from the tank. Changed plugs in the Onan once. Outside of that, sorry can't help