So If you have a Twin Cam 1998-2006 they have hairpin style cam chain tensioners. These tensioners have issues. I know a few guys who have a tone of miles with no issues. I know way more guys with 30k or less and have had major issues. There is about 3 ways to get rid of this problem. Andrews makes a hydraulic tensioner conversion kit, S&S makes a gear drive kit, and H-D has a new Screamin' beagle kit. My kit of choice is the S&S gear drive set up. It is the strongest option. I'm not going to go into the reasons but this may not be a option if your pinion shaft runout is too much. It is also the most expensive, as they say you get what you pay for. Normally I never endorse Screamin Eagle products they only make a few things that are worth owning and there is almost always a better aftermarket option. However, there hydraulic upgrade kit is the cheapest and most cost effective way to go. If your budget is tight this kit is it. It comes with a new billet plate, the upgraded hydraulic tensioners and new high flow oil pump. You'll need extra bearing and gasket kit too. And about 600 bucks in special tools. Take it to a shop to get it done but get it done. Not really the garage style fix.
Here is the stock set up notice the spring style tensioner.
Old plate, old tensioners, this one only had 11,400 miles. you can see the wear and pitting on the shoe.
Here it is installed. The new tensioners are hydraulic and the tensioner material is improved. This will make it run a little quieter and smoother. A must do deal if you must have a1998-2006 twin cam. Oh yeh and if you have a 2007 or newer it has this upgrade even though our good friends at Harley swear this was never a problem.