I have 72,000 miles on my '03 Roadking (Fuel Inj.) I checked my spring tensioners last fall. (60,000 miles?) They were worn by only maybe a 16th of an inch. Now I realize that you were asking about hydraulic tensioners but since you are a tech, I have a question for you.
I have developed a knock that is very noticeable at idle. Just a steady, fast knock. There is no effect on the performance of the bike. It is all stock and runs great. Hard to tell if there is a change once you are moving what with all the exhaust and wind noise. But my question is, If the tensioners are bad, would they knock like that? Just looking for a place to start. Thought maybe cam-bearings too. I took the stethoscope to search for it and it is just as loud down by the cams as it is at the top of the front cylinder. (It isn't very loud anywhere near the rear cylinder.) It is just as loud on the primary side also. I thought easiest first right? This weekend I was going to remove the primary cover and see if anything is going on with the sliding cam on the engine compensating sprocket. Was thinking that if that sprocket nut were loose, that sliding cam would be knocking around.
Just fishing for now. Going to try to get after it somewhat this weekend. Have you had a common problem that sounds like this that you have seen? Spring tensioners do that after they've gone? Do my thoughts seem reasonable?