Im going to go out on a limb here and assume the worst.

I know we have loads and loads of intellegence on this board..Ive seen the pics from the Expo :lol:

So the whistle has a Hz property, It tends to run in cycles. It starts quiet, quiet >= to 1700 rpm and begins to cycle at about 2000 on (a bit louder) My concern is that there could be a bearing that is about to peace-out on me. Has anybody had a bearing commit suicide..maybe you can describe the sounds you heard prior.

One last question, I know honda (type-r in particular) is known for tappy valves, but could the whistling be due to high cycle pinging (made up that term)

Thanks
Dev