I have an Onan 5500 in my MH and it's been a real PITA. In the winter of 2011/12. I had cardiac surgery and couldn't get out to the rig to do the "once motnh" routine. The damned thing hasn't run since.
It will crank, but spits out great gobs of white smoke, backfires like crazy and quits about 5 seconds after I let go of the start switch. I'll have to take it to an Onan pro to get it sorted, as I've run out of ideas. It might be a while, as our RV lifestyle relies heavily on FHU sites. When we bought the rig at 8 years old, the generator had 48 hours on it. We've used it for real on two trips into Eastern WA in summer, when we need both a/cs. With that and "exercising" it, we've added 8 more hours in three seasons.
I have a stong suspicion that the problems are related to gasoline containing ethanol. Onan is very speific about not using it. Get real, guys. The generator draws from the vehicle's tank. I get about 8 mpg. Am I going to drive many extra miles trying to find gas stations with ethanol free fuel that costs 50 to 75 cents more a gallon? No way!
I'll get the generator fixed before we put the MH on the market when our travelling days are over. Until then it's just extra dead weight we're dragging around.
