I need a source to buy a NON RATTLING gas cap for my 2003 Anniversary Edition 883 sportster. Got to have a vented gas cap that won't rattle. I took a punch and pinched original cap from from underneath...stopped the rattle...but created a vacuum problem leading to collapse of vacuum tube to petcock. Discovered all this after EXTENSIVE work to carbuerator, to no avail. Any and all comments on where to find cap or on vacuum issue are greatly appreciated... KEEP THE RUBBER SIDE DOWN.