The screw isn't touching the stop. That is because the stock linkage doesn't allow the governor control arm to move through its full range of motion.
There are 3 things to do to improve this.
1 - adjust the length of the rod from the pivot linkage to the governor arm (by bending it, or cutting and welding it) so that the pivot linkage is more "sideways" and less "up and down". This way the pivot linkage moves the rod more through its range of motion.
2 - the long arm of the pivot linkage that the rod to the governor is attached to should be made longer. Cut it, piece in about 1/2" to 3/4" of material, and weld it back together. This again will make the pivot push the rod more with less pivot motion.
3 - drill a new hole in the governor control arm a little shorter than the factory hole. Maybe 1/2" to 3/4" shorter. This way the rod will swing the control arm more.
You still won't have "full" range of motion in the governor, but you should get enough to go from a nice slow idle to 2000 rpm with stock spring.