looking for a picture/figure showing the location of the APT adjust screw on my Q-jet.......1980 model chevy carb, should have the capability on this carb according to the info I've found in my web searches......dont see anything on the exterior of the carb that it could be.......none of my reference material shows it....any threads on here with a diagram ????

 

APT screw - Is this the lean stop for the power piston, or something else?
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ok, just checked with my main man Doug Roe - it's below the power piston, but essentially does the same thing as the lean stop for the power piston...

No, you can't get to it from the exterior, accessable from the inside. I can't easily find a picture of a q-jet that would show it, but if you can find one, I can mspaint an arrow for ya

 

Yeah, it's in a well just in front of the main power piston, inside the float bowl. You can make it externally adjustable but not without drilling out the airhorn from the inside, tapping it for a plug and screwing one in (so you don't have a big hole in the top of the carb where dirt can get in after you're done making adjustments).