2004 VN1600 Mean Streak with 31,000 miles and very well kept. I have a noise from the #1 (front) cylinder head that sounds like a loose valve. I will get an occasional small backfire when I let off the gas and the idle fluctuates 50 rpm up and down. This came on very gradually. Since there are no adjustments to be made to the valves I was wondering if it could be the front cam chain tensioner. Any ideas before I take it in to my Kawa dealer?