So my Goldwing sounds and runs amazing, EXCEPT when I really get on it (in any gear)> It sounds like a loose belly pan or something (only it doesn't have an aftermarket one). It's like a metallic rattle or vibration of some sort. Smooth, even acceleration does not produce the sound. Any ideas? This is my first Goldwing, so I'm not sure if this is normal or not, but I doubt it.