Power piston stop

[deric83616]

Edelbrock 1901
The power piston stop keeps primary needles from entering the jet far enough to keep the car from running rich.  When compared to other Qjets I have the edelbrock power piston only moves downward about 1/4 what the others do. The stop in the base plate of the edelbrock sticks up over 3/16 of an inch while the others are basically flush with the top of the base plate.
The piston stop appears to be adjustable by removing a plug in the front of the base plate and adjusting a screw in or out.
I bought this carb new and have been trying to solve the rich problem for awhile. I've got Cliff's book and Lar's papers but can't find much on this problem. I suspect that the adjusting screw was screwed all the way in when manufactured.
If I'm on the right track what the best way to remove that plug and adjust to the stop.
Thanks
Dave

[Cliff Ruggles]

When you get time contact the shop, we have an external screw that we make for those.  It has a spring on it so it will hold the adjustment, and takes a much larger screwdriver for easy access.....Cliff