The bike is a 1983 XL600r with 12 k miles on it. It jumped time on the previous owner who said it was the tensioner. I just reasemebled the motor with the old parts and some new parts. Cam gears look good, chain looks good, tensioner seamed to be working. I just tore it back down due to back fireing, popping, no idle, high idle, hard starting and at WOT it would pop, and stall until I let up. Great power when no symptoms show. I purchased a new wiesco cam chain, and have a newer tensioner. In addition, I noticed that the exhaust lobes were pitted and am finding out how hard it its is find 1983 cams. I could have it hard welded and ground but that is a future plan if this does not work. I used a diamond hone and removed .003 from the lobes and then buffed them out. The lobes are still with in spec at 1.216 and spec is 1.213 for ex. I was care full to keep the same profile . Take a look at the video of the chain fit the the upper gear and the lobes and give me some thoughts. this is my first bike other than a hodaka 80 in 1984.