I adjusted the low boost fuel screw today(only 2 clicks) and wow what a differance!!! but what is the little hex screw with the jamb nut on the top of the pump? it's covered by the round tin cap and it goes through the top cover. Also anyone know what does it adjusts THANKS in advance, Ryan

 

That's the smoke screw. It sets the starting position of the AFC cone. The further in you set it, the more fuel you can get without boost. Hence the name "smoke screw."

 

The smoke screw basicly pushes the fuel pin down farther so it's fueling more at and idle and low speed.

I don't like touching it because it makes it smoke too much at idle and when the smoke screw is down it is WAY to easy to smoke out intersections under light throttle.

Hey Dave, remember the kid with the Grey 89 at fall brawl that kept whining because he wanted his smoke screw down farther after you adjusted it back up?