Originally Posted by
nitroal
make sure you have your motor square to the spur. if it is crooked, it will be louder and wear the gears faster.
On Xray 808/ xb9 the spur/bell gear are not supposed to be square to each other, make it square and you get mesh problems, the way it's designed, even states a warning in the manual.
With using paper you can still get it too tight or loose, you have to look what the paper looks like when you take it out, if the paper has been broken its too tight if the crinkles the gears make are soft edged, it's to loose, also is good to listen after meshing it also, get a ear for what sounds right.