"Richard Riley" wrote

It had an engine that I thought - at first glance -
would make a terrific Ultralight engine. 4 stroke, about 50 lbs and
50 HP. Then I found out that it had a TBO of 55 hours.

If it ran at 35 or 40 HP, what would the TBO be? If it were 200 hours, it
still might be a good ultralight engine.
--
Jim in NC