How long have you gone without changing the oil in your small engines?
The oil related issues seem to be more prevalent with newer engines, especially the ones for generators.
There seems to be some type of sensor or something that is in newer generator engines that will actually not allow the engine to run if the oil is too dirty, which comes from age and usage.
To be fair, the longest I've used a given generator is probably 800 hours, which was an on-board onan in an RV. I prefer to run less expensive generators (like Champion) when I'm able for RV boondocking and try to save using the Onans.
I do have a 20KW generator that's due for service this year. It runs once a week for 15 minutes - total hours are around 500.
I generally change the oil after an initial 8 hour break in period (or whatever is recommended in that manual). In every case that I can think of, that first oil change contains a fair amount of very small metal, so I think that break in period is probably the most critical thing.
After that, I (generally) follow guidelines which can be as much as 100 hours run time.
I keep track of it by installing inductive hour meters (these wrap around the spark plug wire) and use a label maker on the generator to indicate the date/hours of last oil change.
One thing I don't do as well as I should: I do not change the oil annually if I haven't had run time... I've just got too many motors.
I think all of my generators have oil level switches, I don't know of one that has a switch for oil "dirty" - I'd expect that on something fancy and expensive like an Onan.
