It is a brushless model.
When you say gear mesh do you mean the cogs underneath the plastic cover?
If is I checked that they lined up ok when I readjusted the slipper clutch
The noise is most notable at low speeds but u can still hear it at high speed too just not as bad.
K i started a youtube acct so i could add the video that way, hopefully this link will work:
http://www.youtube.com/watch?v=7HqvPWCkGpY