ultralights the engines have totally different overhaul philosophies.
you are trying to compare apples, pears and oranges.
yes they are all fruit but none are the same.
I would not ever change my Continental O-200A to any other engine.
it is totally absolutely trustworthy.
btw TBO is a meaningless concept in privately owned cat B aeroplanes.
the engines are run on condition.
overhauled parts are for schmucks. real engines work on replacing worn bits.
I have sitting beside me 4 new O-200 cylinder assemblies. for $5200 I get new pistons, new rings, new wrist pins, new cylinders, new heads, new valves, new valve guides, new valve springs, new retaining clips. what I carry over from the old cylinders are the bits that don't wear hardly at all. rocker assemblies and such.
there is a flying school in florida that ran either lycomings or continentals on condition. with very regular flying one engine was run for over 4,000 hours.
dont believe the dinosaur rubbish. it will take you down the garden path.