Generator hours - when is it too much?

You probably should tell everyone the make and model of generator.
Onan for example will have longer life than "fly-by-nite" brand.
But even life expectancy of an Onan will vary by model.
That way you will get the best answers I believe.

That's really hard to answer. I have an old 2000w Honda that's close to 20 years old and probably has around 8000 hours. Also have a Coleman 3500w that's around 15 years old and close to 4000 hours. Then I have a Generac 4000w that is about 5 years old, less than 500 hours, and needed to be rebuilt.

All had the same maintenance done on them , except the Honda, which I got used when it was 4 years old.

I think older ones were just made better. I'd say just keep up good maintenance and storage practices and when it dies, it dies.

If you are talking about a generator you already own, as long as she starts up and runs fine, keep running her. The problem is most motors die from abuse and neglect long before they litterally wear out.

If you are talking about buying a used generator. I would look for moderate hours. A 10yr old generator with 3hrs on the clock has a high probability of being a problem due to neglect. Likewise a 2yr old generator with 10,000hrs has likely lived a long hard life.

I have not seen a properly maintained Onan wear out.

On the other hand, I've seen many 10+ year old motorhomes with 5 hours on the clock, which almost certainly means a carb replacement, not to mention that the oil in the genset is likely sludge, and the windings are likely corroded and worthless.

If I had a choice between a model with thousands of hours on the generator (and the owner has done basic Onan upkeep like oil/air filters), I'll take that any day over a genset that has not been run since the PDI when the rig was new.

A couple of months ago, I replaced a fuel pump on an Onan Marquis 7KW that's installed on a mobile tire service truck. The generator has 17,000+ hours on it without a major overhaul.

As others have stated, I would want a genset that has been run (preferably consistently over its lifetime). Hard to be sure that was the case, but a 5+ year old genset with very low hours would likely not make my list. For high hours on a cheap genset I would be concerned period, but would likely draw the line at 100-200 hours if that could even be known. Quality gensets are another matter. If I believed the unit was properly maintained and run up to temperature consistently, then I would not be overly concerned with several thousand hours on the clock.
Commercial gas gensets that are run hard (long) easily last 10000+ hours.

Thanks for the guidance so far. I am looking to possibly purchase an older motorhome so I do not know yet what generator it might have so am looking for good "rules of thumb" to guide my process. I have seen postings of 10+ year old motorhomes with generator hours less than 50 ...

funpilot wrote:
Thanks for the guidance so far. I am looking to possibly purchase an older motorhome so I do not know yet what generator it might have so am looking for good "rules of thumb" to guide my process. I have seen postings of 10+ year old motorhomes with generator hours less than 50 ...

Best idea might be to listen to it start and run, measure the output--volts and cycles. Beyond that, it is probably a crapshoot.

Properly maintained and following manufacturers recommendations todays generators like Onan, Kohler, and many others will probably give you dependable service for as long as you need it to. Again with good maintenance they are very durable machines.

I purchased my 1995 vintage motorhome in 2013. It was a monument to neglect and abuse as evidenced by the fact that I developed a bearing knock in its 460 V8 at about 62K. Its 7K Onan had 1,136 hours on it and didn’t run well. I changed the oil and both the oil and air filters, replaced both spark plugs and wires, a circuit board, and took apart and cleaned the carburetor. For a total cost to me of about $200 it now runs great and appears to be reliable.

I suppose what I’m trying to say is that there’s hope, even for a severely neglected generator, if you start out with a good make to begin with.

Steve