Strange Whirring Sound

Learned collective…

I check started my VF yesterday for the first time in three months. It appears to have developed a whirring sound, variable with engine speed, that sounds like it’s coming from the vicinity of the clutch cover. I’ve not been able to determine if it’s the clutch end of the cover, or from the starter end.

It cranks perfectly with no apparent unusual noise if the kill switch is off; it also starts first push (not with the kill switch off, obviously).

The starter was replaced last year with a VFR750 unit if that’s important. There was no such whirring noise when the starter was first installed.

Any ideas what it could be?

Edit: I’m trying to add a video of the sound, but no joy.