I just recently bought a brand new2012 Suzuki Boulevard S40 last month. The bike has 10 miles on it. I noticed when I first took it out for a spin that when I start to decelerate, I hear a high pitch humming/whirring noise coming from what I think is the engine. This is my first motorcycle and it just doesn't sound right to me(I'm maintenance savy and car engine savy.) Just wondering if this is normal because it is brand new, and if the noise will stop once I break it in some more. Any help is very much appreciated. Thanks.

 

Hi. I just got an s40 (2018) and have the same problem. Did you resolve your problem?
Thanks.
Lolocowboy