1500 hours is a joke. I've got chonda powered generators with well in excess of 5000 hours on them,and 16 Honda powered air compressors,2 of the compressors are my originals I bought almost 10 years ago,made in japan. They've got in excess of 10000 hours and 1 of them is closer to 15000 hours.
None of them has had the head off. I use tc-w3 in the fuel,and mos2 every second oci.
Summertime I use Walmart 5 gallon pails,15w-40,and winter I use Walmart 5 gallon pails of 5w30.
I change the oil every second Saturday,or every 100 hours,whichever comes first.
My retailer is in awe as to why my small engines never require service. I use the cheapest oil I can buy,and the only real difference between me and other crews is the use of mos2.
I had the oil alert fail on a 3500 watt generator years ago,however the engine had already run a steady diet of mos2.
So my guess is it ran without oil for at least a full working day before it locked up. I got the call that the generator was seized.
I got there,removed the pull cord,used a 3' pipe wrench to break it loose,and poured in about 2 quarts of transmission fluid(all I had in the truck)
I ran it in the transmission fluid for a few minutes while I went to the co-op and bought oil.
Did 2 quick drain and fills,running the engine at full throttle,the first drain mud came out,the second the oil was black but not gritty.
Filled it up with 15w40 and told the guys to get back to work.
That generator is still in service,consumes no measurable oil between changes,and still gets mos2 every second oil change.
Not bad for an engine that was siezed.