Base Plate screw ?

[MBP]

Hello. I got back my base plate (thank you Cliff) from my 1969 Chevy. There is a screw on the front of the base pate that I'm confused about. Not the needle ones. This screw and spring is also on the front, just right of the PCV hose connection. It appears to raise or lower a wire piece the will fit into a small hole at the bottom of the power piston assembly well.
My questions are how far in does this screw need to be screwed and what is it's purpose and what are the effects of it not being in correctly? Thanks.

[Cliff Ruggles]

The screw is to raise and lower the power piston.

If I did the baseplate here it was set back to the factory setting.  You have the option to fine tune after the carb is back in service.....

[MBP]

Thanks Cliff, appreciated.