OK - here's what happened. CM400A 1979 with less than 3000 original miles. Did an oil change and adjusted valves on Saturday, as I has some valve noise (and I am not sure anyone had ever looked in there before). Ran great, no issues. On Sunday I met some friends for a charity ride and BBQ - did about 100-120 miles total between meeting up, coffee and the run itself, mostly back-roads under 50mph, except for the last 20 miles. The end of the run back to the BBQ was on the highway - I was at 65mph steady for that last part - everyone else left me in the dust, (thanks guys - but that's a different rant.) and I pulled in about 5 minutes after everyone else. But when I pulled off the highway and slowed, the bike ran rough and hesitated a bit. I assumed the old girl had enough - I parked it at my buddy's garage and had a few adult beverages, got a ride home and came back for her the next day. 20 minutes of back-roads to get home and when I do - there is a very distinct ticking noise at idle now. Checked the oil and it was a bit on the low side, but just at the bottom mark, so I topped it off and drove around the block. The ticking is still there, but less now. I am going to check the valves again tonight to make sure I didn't mess up something, but could a relatively short high speed ride like that do serious permanent damage? What should I be looking for?