No need to go into how this happened. I should have caught it earlier. Ran my bike for 263 miles and discovered I was WAY down on oil. The bike took more than a quart to get it the dip stick back to the top line. Possibly another half pint or so down. Just barely registered on the bottom of the stick. The bike was run a number of times without problem, not in hot weather and not hard. It seems to be OK. A valuable lesson learned as to always check and not trust others. Opinions appreciated as to probability of damage and things to look for indicating same.