I finally got my 72 Combat running last night and took it out for a spin. Commandos don't take a back seat to any other bike as far as a great sounding exhaust note! While I was riding, it dawned on me that I had never heard a Commando actually fired up, although I've lusted after one since my first trip to a Norton dealer in 1969. Anyway, on to my question. The the bike starts, idles!! and runs well. Once it was warmed up I noticed a rapid tapping noise above around 2,500 rpm, which was loud enough to cause me concern. Now, that may be normal valve clatter, but I wouldn't know what normal sounds like. While holding any steady speed in any gear, the noise is really noticeable, but it disappears upon acceleration and in not noticable while at idle. Valve adjustment clearances are spot on for a Combat. I know questions about sounds are difficult to answer but I would appreciate any suggestions. Kinda sounds like tapping a pencil point on the top of a metal desk. I've spent months working on this baby and would hate to blow it up due to my ignorance. So, is it normal or abbynormal?