Carb assembly question

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Carb assembly question

Postby gotmud7 » Sat Jul 25, 2009 12:30 pm

Hopefully someone can answer this question for me. I am quoting the 1972 Vega Shop Manual, and have included the diagrams. Rochester 2bbl carb. Page 6M-9 for those interested.
"4. Turn caburetor upright, then drop the pump discharge ball into the pump discharge hole. Ball is 3/16" diameter steel. Install pump discharge spring and the discharge retainer, making sure that the retainer is even or flush with top of casting". Ok, I have the ball. Exactly where is it going. See pictures. The first 3 steps have nothing to do with step 4. In a IECO article I have, it says to "plug the hole in the Power Valve and enlarge the main jets." Do I stick the ball under the Power Valve? It fits great - like it was meant to go there. Or is it supposed to go somewhere in the Accelerator Pump Assembly (came assembled in rebuild kit) or in the Accelerator Pump Spring hole. When I dissasembled the carb, no steel balls were present. The ball came loose in the Carb Rebuild kit. I have larger jets also if needed. Assuming the "52"'s that were installed are factory. Mark, gotmud7@aol.com
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The only Vega's that only had a little rust were the ones still on the assembly line.
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Re: Carb assembly question

Postby kgroombr » Sat Jul 25, 2009 12:43 pm

I think this a rochester 2gv. Here is a manual online that will hopefully help. A bit more detailed than the shop manual.

http://www.oldcarmanualproject.com/manu ... /index.htm

Ken
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Re: Carb assembly question

Postby gotmud7 » Sat Jul 25, 2009 2:35 pm

Thanks Ken. I have a copy of all that. I also have a Rochester book, and another 2bbl manual. unfortunately they cover all years from the 1950's to 1980's.
The only Vega's that only had a little rust were the ones still on the assembly line.
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Re: Carb assembly question

Postby res0o7eb » Sat Jul 25, 2009 3:32 pm

Figure 8 of the on-line manual that Ken posted shows the location of a Pump Discharge Ball.
Looks like it goes in the power valve chamber.

http://www.oldcarmanualproject.com/manu ... 07_jpg.htm
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Re: Carb assembly question

Postby heinz057 » Sat Jul 25, 2009 7:34 pm

it goes in a hole in the bottom, below the acc pump spring , so fuel does not go back into the fuel bowl when you step on the gas
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Re: Carb assembly question

Postby gotmud7 » Tue Jul 28, 2009 3:49 pm

Ok, I went back and re-read the description in the online manual. Clear as mud. It sounds like there should be a check valve ball at BOTH the Power Valve, and the Accelerator Pump spring. This thing has a gas leak between the throttle plate and the main body. So it has to come out anyway. Mark
The only Vega's that only had a little rust were the ones still on the assembly line.
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Re: Carb assembly question

Postby myvega » Thu Jul 30, 2009 8:47 am

No, no, no, no !!!!! You've got this all wrong. There is no check ball under the power valve assembly. Removing the power valve and upsizing the main jets is a performance upgrade, yes. But it has nothing to do with a check ball. There are 2 check balls in a 2GC. The smaller of the two is located under the accelerator pump spring and is often lost if the carb is turned upside down with the top removed. Not all 2GCs have them however. Some later versions do away with that particular ball, but most still incorporate it. The second ball, and larger of the two, is located under the cluster, in the accelerator pump discharge tube. Remove the cluster and you'll see one of the exposed holes has a small steel "T"swedged into it. Remove that "T" and a spring and a ball will come out. This is to keep the accelerator pump discharge tube full of fuel all the time, so the pump shot is there when you need it. More times than not, the ball is stuck in some crap that has formed in the bottom of the channel. I highly recommend you have the main body and cluster glass beaded. This will dislodge any gunk that forms in the passages. Let me know how you make out. I'll be glad to rebuild your carb for you if you want. Just holler.
Jim Sheaffer
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Re: Carb assembly question

Postby gotmud7 » Thu Jul 30, 2009 3:50 pm

Thanks for that reponse. How does this sound? When I remove the cluster, look for the t wedge thing. If its there, then a check ball should still be there. And still move freely. I soaked mine in some carb cleaner for awhile. Under the accelerator pump spring, there is also suppossed to be a check ball. But may or may not be there depending on either it got lost, or that particular model did not come with a check ball. Ok so far.
If I take out the power valve and enlarge the main jets, how do I plug up the hole the power valve was in? Is this mod worth it for a daily driver? One last thing. Do you know what size main jets are supposed to be in there? It had 52's when I took it apart. I upped it to 54's when I thought I plugged the power valve. I also have a extra pair of 56's. 1972 Vega GT, automatic, probably a California car (has AIR pump)

Oh yeah, it has an Edelbrock VR-1 aluminum intake, and a Headmen full length header. Thats why I thought I would plug the power valve.
The only Vega's that only had a little rust were the ones still on the assembly line.
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