I have a 2003 FLHTCi with about 40,000 miles and a big bore. I replaced the cam tensioners and put in the upgrade kit (+ a set of 203 cams) over the winter. Cost about Can$1500. I did it as preventative maintenance just like replacing the timing belt on many of todays cars. When it was opened up there was no wear on the cams. However, I have a friend whose cams were pretty well shot at a similar mileage. There doesn't seem to be any rhyme nor reason. Only real problem i have had with the bike is a failed clutch replaced under warranty although the seat back rubbing on the top box makes me spit.