The 1/16 at a time on the pressure screw doesn't make much difference, it will take you forever. After changing the pressure you'll have to reset the low and high speed adjustments.
Bill...If you were to re-read my post more carefully you would see that I said 1/6 turn, not 1/16 turn
BUflash
If you are unable to get the pump & carb to operate to your satisfaction, you may wish to try what I did with my pump carb. A year ago I assembled an OS 60 FSR from a collection of parts I inherited but I had no carb. My pump carb fit perfectly so I reduced the venturi size from .375" to .305" for operation on muffler pressure using a piece of .375" OD plastic tube with a notch cut out to fit over the main jet tube in the carb barrel. I screwed in the inverted mixture screw to open it fully. The result is that it runs just beautifully with the most linear 2 cycle from idle to full throttle that I have ever seen, and on 0% nitro to boot.