Onan Generator

If it were me I would buy a used one - plenty of low hour onans available - my next choice would be rebuilt which will save you 3K. That's assuming that your current Onan is actually caput.

Will the engine turn over, or is it seized?

A generator engine just does not die without some prior symptoms. Was it using a lot of oil when you last used it? Did it seem to take a long time to get it started when cold, indicating low compression?
If the engine was running fine and just shut down, it may be something as simple as a clogged/leaking fuel line. Low oil shutdown, etc.
As suggested, take it to a QUALIFIED shop and have then do a complete diagnosis of the issues and then make a decision as to what needs to be done.

You are looking at about $5500 to buy a new onan. I would call a few independent Gen shops and ask what they would charge to either rebuild the engine or just short block the engine. Gensets have 2 sections. The ENGINE and the GEN part. Usually, a qualified shop can rebuild or replace just the engine for less than $2000. Saving you $3000. Onan Gensets are designed to be rebuilt, unlike the disposable ones you get at HD or Lowes or even Harbor Freight.

Sorry it was Northern Tools not harbor Freight. The generator was running for about an hour and just stopped. Under no particular heavy load. I personally changed the oil and filter on a regular basis.

I looked at Harbor Freight webpage and saw 19 generators but no Onan of any kind.

I think I'd get one more opinion somewhere else before I spent any money on it.

Did you change the oil and filter on a regular basis?

How exactly did the generator "stop"? As already asked, was this shop an Onan/Cummins facility? I'm assuming since this is on a class A motorhome that the generator is at least 5000 watts, with a screw-on oil filter. Perhaps this shop just looked at the houmeter & just assumed shot because 3200 hours is unusually high for a gas Onan. We need more info about the generator and the symptoms of it shutting down. But 3200 hours doesn't seem excessive/worn out to me, even on a gasser!!!

Depending on the model of generator the engine is likely shot. If it is the Onan KY series (generally 4000 watt and under), they have a typical service life of around 2,000-2,500 hours. If it is the 5,600 watt or larger gasoline models they tend to last somewhere in the 3,500 - 5,000 hour ballpark, assuming regular oil changes and maintenance.

As to what to do, if it were mine I would be shopping for a pull out Onan, lots of RV generators get very little use, therefore it is fairly easy to find a 15-20 year old pull out Onan from a coach that is being scrapped that is the same as your old one for $750-$1,200 in good running condition, or often half of that if it has issues like gummed up carburetor or a bad control board.

DothanAntelope wrote:
Harbor freight has a 7k Onan for 5100 dollars. 115 dollars to deliver.

Harbor Freight sells Onan generators?

Was it an ONAN dealer that said the motor was shot.