My 05 WG with 26K miles sounds like I'm running a turbo when coming to a stop. I pull the clutch in and the whistle sound stops. The clutch seems ok. Looking for ideas on what this could be.

 

only on decel? when downshifting?

did you adjust your primary chain or final drive belt recently?

my bike has a whine when the primary chain is too tight, and a kinda..."buzz whine" when the final drive belt is.

 

Check your drive belt...a lose drive belt will make a loud whirling sound on deceleration.

 

I have adjusted the primary chain and put new back tire on this year. I will check both these two possibilities today.

 

Well I first loosened up drive belt and did test run. That didn't stop what sounds like a faint siren behind me. I then re-adjusted the primary chain and that has stopped the noise!
Thanks for the tips on what to check.