How to rebuild a Rochester 2GV - a pictoral essay...

Discussion in 'The Mixing shop.' started by Kirk, Oct 22, 2005.

  1. allforbob

    allforbob New Member

    I rebuilt my carb per your instructions, and it runs fine. The problem I`m having is after it runs a while and is all warmed up, if you shut it off for a while then restart, it seems to be flooded a little. From what I can tell the fuel seems to be weeping a little down the throttle body, It makes it hard to start, but when you get it running it is fine. Any suggestions? bob
     
  2. gringo6998

    gringo6998 Well-Known Member

    This was very helpful thanks!
     
  3. FIEROCKET

    FIEROCKET New Member

    This is the best site I have ever visted showing the parts breakdown pictures with explanation of step by step instructions. I am glad I found this source. Thanks..:Brow: I am still looking for the linkage hook-up on the choke and pump rod.
     
  4. frankrentef

    frankrentef New Member

    THNX for the time taken to write and document the rebuild, it's been a life saver! Quick question, when you get the carb back on, what is the best way to prime it?

    THNX
     
  5. victor44

    victor44 New Member

    This is a superb thread, never seen a better write up on working on an engine, better than Haynes books. Brilliant good job Kirk!
    Victor44
     
  6. kayserpor

    kayserpor New Member

    :TU: this is very insightful for rusty minds, thank you for the refresher course;
    Rebuild Rochester For Dummies 101
    thank you very much for the time it took to publish this article
    :Smarty:
     
  7. jettfuel

    jettfuel New Member

    Thanks, waited to long reasemble :gp: :beers2: SWEET
     
  8. Cliff R

    Cliff R Well-Known Member

    Excellent information.

    I would add one comment based on this information:

    "The ball is dropped into the accelerator pump discharge hole, followed by the spring and T-shape retainer. These pieces form a one-way check valve to ensure the pump shot goes into the carb and no air is sucked back."

    This is the area of these units where we see the most trouble. Using a steel checkball the same size as the new aluminum one, gently install it at the bottom of the accl pump well, and tap it with a brass punch to form a new seat.

    At least 80 percent, if not more of these units will leak some fuel back into the main fuel bowl on the down stroke of the accl pump. This reduces pump shot and fuel delivery to the engine. Whether it's the aluminum check ball or just the fact that the seat is at the bottom of the bowl where any dirt, debri or water would accumulate, not sure, but it's rare to find a unit that has a positive seal between the check ball and the seat.

    I use the small steel ball from a Holley kit, and gently stake the old seat, then put some fuel in the bowl and test the operation using the new accl pump. Fuel should be easily drawn in under the pump, but none should push back into the fuel bowl on as the pump is depressed. It may take several attempts at forming a new seat to get a positive seal at the aluminum check ball, but the extra effort is well worth it as carburetor performance will be improved dramatically..:) ....Cliff
     
  9. kenlan21

    kenlan21 New Member

    YOU ARE A LIFESAVER!!!!!!!!!!!!!!!!! I rebuilt a Rochester carb to a 77 mercruiser...Not much difference AT ALL! That saved me a lot of trouble and $$ for a new carb! Now I can use that $$ for something a little more fun!!! THANKS!!!!!!!!!!!!!!!!!!!!!!!!!!! Best post I've ever seen! The pics are awesome!!!
     
  10. sleavem

    sleavem New Member

    I think you just saved my butt! I tore apart the carb about 2 weeks ago and cleaned it, but haven't gotten time to put it back together 'till now. I did pretty good, but had some hang ups. Not any more! I really appreciate your help. Excellent How to!
     
  11. ssmock

    ssmock Well-Known Member

    Great thread and timley as I am just starting to rebuild the carb. Thanks for all of the pictures, it really helps.
     
  12. indymanjoe

    indymanjoe New Member

    send me a pm want to buy you lunch.awesome post the best ive read!!!!!
     
  13. monsterced

    monsterced New Member

    I just found this and wanted to say that this was a great thread. Very helpfully. THANKS.

    One question for anyone. My carb is for a Marine application and when I took it apart I realized that the "Main Well Tubes" were not in there. Some one didn't put them back in before. How important are these? I called a local shop and they said I would have to hunt around for them as misc parts but that they were not really needed. I do know enough that if it is in side a carb there probably needed. Any help?

    Chuck
     
  14. RamAirZ

    RamAirZ New Member

    awesome thread! I just did the carb on my 67' Impala tonight, but mine does not have that mesh filter or use 2 balls, just the one with the spring and t-retainer. i have no place for the 2nd one, just a spring down in there. I'm just trying to figure out if I have the fast idle cam hooked up right (the piece with the key hole). It looks right but when operating the throttle it basically falls down when I pull the throttle back and it barely open the choke at full throttle (off the car) Also someone had removed my fuel filter in the carb and replaced it with an external but left that spring in there, is it really needed with no filter?
     
    Last edited: Aug 8, 2009
  15. 70 GS 350

    70 GS 350 Well-Known Member

    How do I properly adjust the 2 screws on the front of my 2bbl carb on my 70 skylark?
     
  16. 70ElCamino

    70ElCamino New Member

    Kirk,

    Four and a half years after your took the time to document this whole process, I was fortunate enough to have stumbled upon your work. It was a priceless tool to be able to work with.

    I would like to express our appreciation, you being able to answer all of our questions with your awesome job of documentation.

    This was a great father and son project, successfully re-building the carb on my Dad's
    70' El Camino.

    Thank You,
    Ron B. and Mel B.
     
  17. 2curious

    2curious New Member

    "A picture is worth a thousand words" and this little job was a lot of fun thanks to your documentation. I rebuilt the 2GC Rochester on my 65 Oldsmobile and about the only difference was that the T shaped retainer, spring and ball check were located under the venturies instead of on top of them. Thank you!
     
  18. chuck_rudd

    chuck_rudd Guest

    Rebuiding a 2 barrel on a car I have yet to run - the two well inserts were missing so I have no idea if the carb worked after the last person messed with it. Where can I buy two of these inserts? Do they vary by serial number? This carb is from a '71 Skylark.
     
  19. Kirk

    Kirk Well-Known Member

    According to the Factory Service Manual:

    "The volume of the main wells is reduced with a removable plastic insert. This results in better fuel control in the off-idle and transfer range."

    Earlier 2G's sometimes didn't have the plastic inserts, so they're arguably "optional". And I suspect the only source for such parts is another carburetor. Which means that you may be forced to live without them.

    My guess is that rebuilding your carb without the missing inserts will still result in a drivable car. I'm not sure how the lack of "better fuel control" will manifest itself. Perhaps part-throttle driving (steady cruising) may be slightly worse fuel economy. Or a bit of hesitation when moving the pedal from idle to off-idle. Or perhaps nothing noticeable at all.

    If you're like me, you hate leaving parts out that were put in for a reason. But I think you may be forced to do so here (unless you can find a parts-donor carb). And even then you may not notice much (if any) difference, anyway.
     
  20. mike de luca

    mike de luca New Member

    Re: How to rebuild a Rochester 2GV Carburetor - a pictoral essay...

    kirk

    this is a great article I just rebuilt my 1967 camaro 2 cgv for the sixth time. i needed to washers under the seat to prevent flooding. I worked great

    GOD BLESS

    MIKE AND ELAINE
     

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