My newly purchased F6B is producing the sound that I never heard before from regular goldwings that I owned previously. This one is making more rumbling sound (somewhere in the front area) as if there's a hole somewhere in the exhaust pipe. Is F6B is supposed to make that extra sound or is there a problem with my motorcycle? The bike is like brand new (only 2k miles), all stock and no mods whatsoever. Please advise, thanks.