And the answer is!
I just replaced the starter on my 06 C because the front armature bearing went bad and I learned a lot about it. The starter on the VTX is fully engaged in the primary gear train at all times. There is NO solenoid to extend or retract the actual starter gear when the start button is pushed. The noise you are hearing is the reverse direction of all the gears in the starter gear train which is triggered by the last comperssioin stroke of the motor after the ignition or kill swith is activated. Kind of a slight "backlash" if you will and it is very normal for this to happen.