125-200cc Flywheel lightening

Hey guys, I am wanting to lighten my stock flywheel on my 2013 Wr125 and am wondering if anyone else has done it before, if so how much weight did you take off and how much of a difference did it make to the throttle response?
I am also wondering if anyone knows the weight of the 2013 cr125 flywheel? As I am wanting the throttle response of a cr125 without having to do the complete ignition swap. Thanks