On Nov 11, 5:18 am, "Albrecht via MotorcycleKB.com"
>> Stay informed about: fzr 1000 rumbling noise coming from exhaust
> I wouldn't entirely rule out a burned exhaust valve, but it's easy to detect.
> Just idle the engine and hold a credit card behind the muffler opening. The
> credit card will get sucked back against the exhaust hole every time the
> piston in the cylinder with the burned valve goes down on the intake stroke.
> The credit card will make a flapping sound.
And that is why "you da man."