At about 5400 miles I began to notice a rattle that seemed to be coming from the valves. I had the valves serviced and also had all the chassis bolts checked. When I got my bike back I still had this rattling sound. I began searching for the source and noticed while going down the road I could put my hand on the gas cap and apply slight pressure and the rattle stopped. I added an o-ring on top of the factory seal and the rattle stopped, after a 285 mile ride, the rattle returned. I checked the screws that hold the cap together, I tightened them. Has anyone else had this problem? Is there an aftermarket replacement cap? Is there a remedy without purchasing a new cap? Any help would be great.