Where is the idle mix adjustment on this carb on a 5.7 350 with Thunderbolt IV?

[theorifice]

I looked around but not seeing an obvious location for the idle mix adjustment screw. What should I be looking for? I can't tell what kind of carb I have.

 

[kenny nunez]

The mixture screws are at the bottom in front slightly angled left and right away from each other. The screws are not slotted but are male oval shaped. You need to get the correct tool from any of the big box auto stores. If your carburetor is in good order the Quadrajets like 3 turns out from lightly seated.

 

[Scott06]

here is maybe not the best video but shows where the hidden idle m,ix screws are and flex tool needed to adjust

 

[Lou C]

Yep be careful because on the port side you may have to thread the tool inboard of the alternator or PS belt depending on the installation. The issue is that they are on the underside of the carb and the big bulky 'stat housing gets in the way.

 

[Scott Danforth]

Holy dirty spark arrestor batman. that alone should be the first order of business.

 

[Scott06]

Holy dirty spark arrestor batman. that alone should be the first order of business.

Common man that can go another couple years...

Neighbors boat (VP 4.3 MPI) was lacking in holeshot, she asked me to take a look at it. Had just had the marina that did winterization do a tune up... cap, rotor plugs and wires ... The flame arrestor made this one look clean - completely covered with fuzz...