Congrats on your RV purchase, I hope it treats you well!
The Onan microquiet 4.0KY genset is very durable. With proper care and maintenance it should last around 5,000 hours! I use the same model in my trailer and its been very reliable. It requires some routine maintenance, but nothing crazy. Your owners manual has excellent schedules for maintenance, I recommend you take a look at them.
On my machine, I change the oil every 100-150 hours, there is no oil filter. Change the air filter as needed, probably once per season. Change the spark plug once per season as well as the fuel filter, which is located on the fuel pump inlet fitting. I also check the valve lash and adjust it once per year. I average about 500 hours per race season on the machine.
Good luck to you
