Mach 3 and spindle calibration

I know there are several forum posts on this but none of them has helped me. So here is my setup.
I am running the CNC4PC C11G board as PWM converts to analog voltage. I am running MACH 3 I also have the LMS belt drive option on my X2 mill which is a DC motor no VFD.

At top end i am getting like 4600 RPM. So I ahve tried the trick of setting my max pulley to 1000 then get the MAx RPM and insert that into MAx pulley and call for a speed of 2300. When I do this my speeds are higher than 2300. I have built a hall effect sensor on my spindle and maybe my speeds are not reading accurate there.

Any other trick you guys have to make this closer to correct?