install a clean air filter.
open carb and open main jet and the tube to which main jet is fixed . it is called emulsion tube . google image it.
clean it thoroughly .. with thin wire or guitar string.
now close your carb.
open 1 rottion the air fuel adjustment screw form fully closed position. ( one rotation is 360 degrees .. i.e if the opening of the screw is like this / rotate it once so the opening is again at / this is half rotation .. give another turn this is one rotation)
now open the idle adjustment sufficiently.
strt the bike .. and adjust the idle slightly higher then normal . say normal pa jitni hothi ha uss sa ziada idle rpm pa set karo.
now tweak the air adjustment screw .. rotate it counter clock wise in increments of 1/8th rotation .. and wait 10-15 seconds . if rpm increases give another small twist .. do this continuoulsly until at one point ( which will be less then at most 2 rotations and .. mostly will be one and a half rotaion) .. you get the highest rpm .. and after giving further rotation the rpm wil drop..
the place where you got most rpm is the best idle air fuel mixture setting .. at that settings you get most complete burn of fuel. .
mostly its set to between 1 and one and a half .. issi range ma kahien idle position hothi ha..