Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

AF ratio when secondarys open

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MRSOFTE:
Good morning

Finally got too the point where I felt tuning my 7028210 by the seat of my pants was over. So I sprung for an AF gauge. So with 69 jets and 46rods and AX secondary rods on a K hanger. It idles at 13.7. heavy acceleration with out the secondary's is also mid 13's. Cruise is 14.6 to 51.1. I'm happy with that but maybe I could go a tiny bit leaner?
Anyway my question is....When the secondary's open it drops too 10.6- 11.1.     Is that good/normal???
Thank you!

77cruiser:
If it goes back 12 -13 it's OK. If not you should lean it out.

Frank400:
When you say you could go a little leaner, do you mean at idle or cruise speed ?  Is that a stock motor or does it have a non factory camshaft ? 

   Assuming it's a pretty stock motor with plenty  of vacuum, I do run leaner than that at idle myself and also a bit leaner at cruise as well.  It's easier to changer the cruise AF with the later APT carbs like I run, but if I were you, here's what I would do, but that is just me.  I would slightly enlarge the upper idle air bleed which is most likely on the air horn on your carb.  That would lean out the idle and also have a small influence on the cruise AFR as well, but much more on the idle which I think you could lean out more. 

    Frank.

von:
I think he's mainly concerned with WOT with secondaries hooked up. Sounds like it needs to be leaned a little on the secondary side.

MRSOFTE:
Yes just WOT. Stock 396 and the Rochester has not been abused by a weird rebuild. The carb has the stock AX rods, I have two hangers a K and M the M is leaner that's the one I'm using. Adjusted the door tension until it bogged then tighten up a bit. Not sure what else too try?  :P

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