500 is nothing. Some of my older rental units (08 and 09 model years) are pushing over 1,000 hours. I wouldn't think twice about 500 hours.
One thing I have found about Onan gensets and that is there is no correlation between number of hours and maintenance required. I've had gensets with 200 hours need major work. I've had gensets with 2,000 hours that ran perfectly with only oil changes. I've had 700 hour gensets that crapped out all together.
The oil level switch was removed back in late 90's, as speculated due to oil slosh problems causing false shut downs.
King Willy! Haven't see you around here in ages! I still remember the tip you gave me long ago. I substituted a spring hanger for the almost rigid one on the Onan's exhaust pipe in my old class B. It made a huge difference in vibration and interior noise. Thank you, sir!
That started me to realizing that most Onans aren't installed as well as they could be by RV makers. Now I have a 2800 running at nearly full load at 56 db(a) 23' from the exhaust. I've only fudged a very little on Onan's installation guide. It's all due to a train of thought that you set moving some years back. Again, thank you!
Jim, "Floggings will continue until morale improves."
'06 Tiger CX 'C Minus' on a Silverado 2500HD 4x4, 8.1 & Allison (aka 'Loafer's Glory')
I hope they get more than that. My 20 year old John Deere tractor has over 1,000 hours on the meter and still running like the day I bought it.
That is a tractor... but your $199 lawn mower is different.
By way of compare, a marine power plant on a commercial vessel, operating at cruising speed (not maximum, but say 80%) is good for roughly a year or about 9,000 hours before a cylinder need to be overhauled.
Or say 10,000 hours.
3,000 hours is a heck of a lot --- when you think in those terms.
Typically manufactures of small engines sell at least 3 grades:
"Junk" grade of 100 hours or so.
Light duty commercial of about 2,000 to 3,000 hours, like the Honda GX line.
Serious heavy duty commercial is 5,000 hours and up.
Only when you pay real money do you get the 10,000 hour engines.