I've watched this site for awhile now and have enjoyed the many and varied threads and now it's my turn to contribute. I know of a V rod that had a very intermittant rattle. The owner mentioned that almost from new once in a while he could hear a slight noise but it was so short that he couldn't say wether it was front, rear, left or right side of the motor. He couldn't make the motor make the noise it just happened under any conditions. Then after a couple of thousand miles the noise happened upon startup with a mechanic near by, the noise was coming from the rear cam chain tensioner. This tensioner uses a spring for initial tension and motor oil pressure when it's running. Following the manuals instructions the rear tensioner was removed and inspected. No problem there BUT there was something missing, NO OIL Drilling, so no oil pressure to assist the spring. The oil way should be at about the 3 o'clock position, you can see a bulge in the casting if viewed from the right side of the motor, I don't want to panic anyone but if you have similar symptoms it may be worth checking or it may be just a one off.