After 17,000 miles I noticed a loud CLUNK when I hit a pot hole or rough section in the road. First thought, steering head/triple tree bearings going bad. Place my hand on the steering neck and hit a bump. The gas tank was loose. I had the 8 deg injectors replaced with the 25 deg injectors and the gas tank wasremoved for access. When the tech replaced the tank, he mixed up the mounting bolts. Apparently, the rear bolt is a little longer and will bottom out in the acorn nut and not tighten correctly when put in the front mount. A simple swap of the bolts and the tank is tight and the clunking gone.