speed not increasing

hi dear friends
i have this file.ngc which is used to produce a workpiece in series.
my issue is that speed does not increase . even when i change #4 parameter in file,ngc
i tested g0 and g1 in mdi and machine moves in 4800mm/min speed without any problem but when i run this file.ngc code, speed is limited to 130 roughly 

i changed z steps from 0.05 to 0.1 and it increased speed but it is lower than what i want and what it should be.