Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: mcx on November 13, 2020, 10:55:36 AM

Title: 7043262 air bleed screw spec?
Post by: mcx on November 13, 2020, 10:55:36 AM

The airhorn located air bleed adjustment screw (under the triangle lock tab), how many turns from bottom is it set?  Thanks.

Title: Re: 7043262 air bleed screw spec?
Post by: Kenth on November 13, 2020, 12:00:23 PM

Depends on Rochester made or Carter made #7043262.
I have found Rochester made units uses #71 pri. jets with #41 primary rods, .083" upper main air bleeds and upper main air bleed screw 1/2 turn up from lightly seated.
Carter made units uses #74 pri. jets with #44 pri. rods, .050" upper main air bleeds and upper main air bleed screw 1 turn up.

Title: Re: 7043262 air bleed screw spec?
Post by: mcx on November 13, 2020, 03:00:00 PM

Thanks Kenth.  What do you suggest based on these numbers?
It's a Carter stamping with 71 jets and 41 prim rods...CR sec rods.
Main bleed  .0725"    upper idle bleed(airhorn) .0525"
Idle tubes .033"    IDCR  .041"  Lower idle bleed .0625"   
 Lower Main bleed .0625"
Idle mixture holes .108"    Idle air  bypass  .108"

Title: Re: 7043262 air bleed screw spec?
Post by: Kenth on November 14, 2020, 07:09:50 AM

Most #7023262 i have taken measurements from has .037"-.038" idle tubes, .045"-.047" idle downchannels, .055"-.056" upper idle air bleeds, .069"-.070" lower idle airbleeds and .070" main air bleeds in bowl. .110" x 2 idle air bypass in plate and .092" added from the hot air choke channel.

If the carbs sits on its original engine i would start with .038"-.040" idle tubes, .052"-.055" IDCR, DA or CE secondary rods with a K-N hanger. Seat the main air bleed screw and use #73 jets with #41-#43 rods. You may open the screw some if rpm decreases at the 2200 rpm tip-in test.

HTH

Title: Re: 7043262 air bleed screw spec?
Post by: mcx on November 15, 2020, 05:28:01 AM

Thank you....I'll set it that way.