So I installed a 2x2 rochester setup on my 56 buick and I cant get the damn thing running.It starts runs at a very high idle for a few seconds then dies.Im running it progressively.The guy I ordered the carbs from supposedly built them so the secondary carb. doesnt have an idle circuit.Im wondering if he did remove it?And I had no idea which one was the primary and which one was the secondary.Im thinking maybe I have them swapped.My questions are; How do I check to see if it does or doesnt have an idle circuit and if I have to remove it,how do I do it? Does it sound like Im on the right track? also what a good starting point for adjusting the idle mixture screws? Thanks
A 2G roch secondary carb will not have idle mix screws at the front lower casting. 1-1/2 turns out for a starter setting. The secondary carb must have it's thottle plates closed tight with ZERO vac leaks, it will do what you say if it has leaks or if you are using the wrong carb as a primary. If you get stumped; make a solid block off gasket on the sec for now, just to dial in the pri one. Disconnect that sec linkage too.
You probably will get a better running setup by running the two -2G's together,it is not more CFM than needed with both fulltime...... I think those are 273cfm each.
Thanks I appreciate the info.I know both carbs have idle mixture screws.So its looking like maybe both carbs are primarys.Great.
One other difference in primary vs. sec is to look for extra thick lower throttle plates on the seconday carb, that is for getting a leak-free sealing surface at idle, when that carb is not in use.
Maybe fashion a quick block off plate to go under the front carb and just run it on the back one as a test. That will tell you which carb is messing up. I ran one of these setups on my 23, got it from Charlie Price at Vintage Speed. Bolted it on and never touched it again as it worked fine, but his did have the special bottom plate with no idle circuitry. Don
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