I suspect my secondaries are not opening on my 305 4bbl rochester carb. When i punch the gas it doesnt have the sound or punch it should,kinda bogs along. I Rev'd the engine parked at 4000 rpms and the secondaries wont open, I soaked the inside and out with carb cleaner and still nothing, Checked vaccums and all the ports are sucking. when i manually open the seconardy jets it gives a awesome sound and pull that i unfortunatly never hear or witness while driving, any suggestion?

 

Secondaries will not open in the garage, or sitting still. The engine needs to be under load. You need to figure out a way to check it out on the street when you punch it.

 

Welcome to TGO. Try: https://www.thirdgen.org/quadrajet

particularly the part about setting the AV tension. Report back if that doesn't help.

 

Me being impatient i loosen'ed the screw explained in the first part, took it for a drive cold and punched it, BOG! so i drove it around till it was warmer, punched it, WHOOOOP! WHOOOOP! Awesome, improvement made, Though i think the carb needs a total rebuild, it hasn't been rebuilt in four years and it sits every winter. So i'll continue tuning later after fishing.....

 

Ok so this question is about changing the hanger on the rochester quadrajet, In the article it explains about changing them, though I don't know about sizes, what size is on it now, and what kind of difference would it make it i lets say up grade to a .520 hanger.