Vibration woes again

[Davew]

Why not just get a slightly longer bolt, double rubber washer it, and not tighten it all the way down? Tank will still be attached, just won't be clamped down as firmly as normal, and shouldn't vibrate?

yeah I just tried a rubber washer again this morning which did make a bit of difference.  might try the combination of that and my drilled out tank bracket.  so frustrating trying to figure it out!!