Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

Two QJ's into one

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F250 Restorer:
I was running a 17059272 on a hp Ford 300.  I wanted the smaller primaries, and a richer idle circuit, so I switched the main body to that of a 17058504.  I used Cliff's inserts for smaller main air bleeds, and Cliff's idle tubes.  Since I used the air horn from the 272, I kept the main air bleeds there at the oem size.  No by pass air.  I set the APT to 2 1/2, but will do the tip in when I have more time.  I used 72 main jets and C's 44 m.rods. 

It fired right up.  I'm still surprised how smooth it idles.  I was a bit surprised to find the mix screws set at only 1/2 turn out.  No more hesitation, and better throttle response. 

Thanks for the help, Cliff.

Cliff Ruggles:
Nice thing about those later carbs, the throttle bodies and airhorns will swap as long as both were the 4 MAB models.  The idle bleeds aren't the same between those units.  The smaller main bores will increase velocity of the incoming air, not a bad thing for a small CID engine.  The 300 in line 6 pulls pretty hard on the carb anyhow, and wouldn't need a large cfm carb right to start with, so no power would be lost going to the smaller casting.....Cliff

F250 Restorer:
Cliff, I was wondering why once in a while, fully warm, after driving 20 minutes or so, it wants to run on.  I have the idle at 750 in park.  I haven't done the tip in yet. 

Cliff Ruggles:
"Running on" is either idle speed too fast, or not enough timing at idle, or both.  Retarded initial timing puts the throttle plates open further, and makes it easier for the engine to want to "run on" after shut down.....Cliff

F250 Restorer:
Rule of thumb as a kid was always 'advance it 'till it pings, then bump it back a tad.'  When I had my dizzy recurved, the tech said to set the initial at 16*.  I did, but the starter kicked a bit.  I will advance it slightly. 

I was thinking of bending the acc.pump arm slightly to lessen the squirt, while trying to improve mpg.  Outside setting was too little.  Any suggestions.

I want to change the cross-drilled s.nozzles.  Do I simply heat housing and pull?

Any experience using a Lokar cable for a kick-down?

Thank you. k

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