Well, I'd suggest changing the oil and filter, again, after running it for a short time, to flush out any remaining metal bits floating around inside. Your best bet may be to take it to your mechanic, and ask their opinion as to what to do. If the whirring noise is constant, and obvious, they may be able to give some diagnosis based on that, and their experience. If there has been a recall on that bike, they can check, and perform any factory fixes recommended, as well.
If metal is grinding metal to dust, it will get worse, and the particles will cause additional wear on other parts of the engine. It should be checked out, as this is not normal, as far as I know, for any bike. Best of luck! Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII