I think I can hear what your talking about but its not very distinct on the vid. It actually sounds pretty normal. I notice my old NV1000 sounds different from time to time. Have you checked for a blown seal/oil in the blower housing and intake? A bad seal usually leads to bearing contamination and then failure. But running our belt too tight can cause bearing failure as well. Typically you get a high pitch scratching or shrieking sound though. Yours just sounds like noisy gear lash in the blower. Nothing to concerning from what i can hear on the vid except maybe your blower has finally broke in ...and not broke

 

So the distinct whistle sound turning into more of a whine is nothing to worry about? The noisy gear lash could be because I had my camera so close to the charger too.

 

Man, those 928 parts look awesome. Thanks for the word on those.

 

No I really don't think so. Mine sounds like that too and has for as long as I can remember. As I mentioned, check for bad seal/oil leakage in the exit of the blower to intake, if it’s dry then don't worry about it.