Ah. Ok. Unless folks install an hour meter on these smaller inverter generators, any hour usage statement is a SWAG.
But seeing as how you are so interested, I'll give it a shot
We boondock most of the time, and in the Southwest we RV every month of the year. AVG run time per day is 5 hours unless it's summer. We try to use hookups in the summer due to the heat, but always have at least a couple of trips where we run both generators 24 hours a day.
Before retirement, estimating only boondock trips, I get about 400 hours a year for 8 years. Now most of that is split between the 2 EU2000is, so roughly 1600 hours per generator.
After retirement, it has at least doubled, so 800 hours for 3 years is about 1200 hours per generator.
Grand total of an estimated 2800 hours per generator over 11 years. Again.... a SWAG.
After playing with these numbers, appears I change the oil/plugs about every 200 hours which is double the recommended, but it is synthetic so I figure I'm good. Plus the oil always looks good coming out (not too dark and smells ok). Spark plugs are always clean.
I was getting concerned about the lifetime of Honda 2000s until I read posts of folks in Alaska and on sail boats, using them for 10,000 to 20,000 hours. So I should easily have at least another 11 years on these!