this is my first time and I'm a little nervous, so here goes. My 2000 road king fuel injected, screaming eagle slip ons and K&N air cleaner, has developed a low grade knock or rattle. It is only noticeable at idle, which after warming up is borderline low. The noise comes from the front part of the engine, but I can't seem to pinpoint it. I had the cam chain tensioners replaced 9 months ago and have 28,000 miles on it. Can you offer any help to a first timer?