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Rochester 2G Rebuild

Discussion in 'Early CJ5 and CJ6 Tech' started by Elvislives, Jan 23, 2012.

  1. Jan 23, 2012
    Elvislives

    Elvislives Member

    College Station, TX
    Joined:
    Jan 22, 2012
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    186
    From a new guy on the block,,,a question about my carb. I have a 1970 CJ5 with the 225 V6 with a Rochester 2G - #7027089. I'm rebuilding the carb and noticed slight pitting on the intake manifold between the two water passages. I'm assuming this IS a water passage to cool the carb/fuel and not something else.
    I had also noticed a tiny bit of water seeping from the head of one of the front carb to manifold bolts before I removed it. There's no pitting on the bottom side of the throttle plate.

    Question: Is there anything I can use on the carb/intake gasket to prevent water from seeping through?

    Question: Is there supposed to be any type of washer on the bolt heads? Something to seal this seems imperative.

    I can't find any mention of this in my shop manuals and the carb diagrams don't even show these bolts. Any/all comments/suggestions greatly appreciated.
     
  2. Jan 23, 2012
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
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    Got a pic? You can host on Photobucket and link them here.
     
  3. Jan 23, 2012
    Elvislives

    Elvislives Member

    College Station, TX
    Joined:
    Jan 22, 2012
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    186
    Good idea - Let me know if this link doesn't work - Picture of bottom of throttle body and intake manifold.
    http://photobucket.com/1970CarbRebuild

    I examined this a bit closer and the passages on the intake manifold look more like intake/exhaust gas recirculation. (WAG) I got my air hose out and blew into one and the air came out the other! I don't have a clue why they would route that through the base of the throttle body. I'm stumped.
     
    Last edited: Jan 23, 2012
  4. Jan 23, 2012
    homersdog

    homersdog Tulsa, Ok 2019 Sponsor

    Tulsa, OK
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    The exhaust passages are to heat the carb I believe. Pre-heated fuel is suppose to atomize more quickly. The 2 mounting bolts that pass through the passages will often be damaged by the corrosive gases in the exhaust, so you might want to replace these with plated grade 8 bolts when you re-install the carb. This carb was used on many different vehicles as you can tell by the chart in your rebuild kit. Maybe the exhaust heat system was developed for another vehicle?
     
  5. Jan 23, 2012
    Elvislives

    Elvislives Member

    College Station, TX
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    Jan 22, 2012
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    I think that's right Grant. The bolts are slightly corroded. Good idea on changing them out.
     
  6. Jan 23, 2012
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2020 Sponsor 2019 Sponsor

    cordele, Ga.
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    Yep it's exhaust. Note the 2g base is cast iron. The exhaust is circulated thru the carb base to pre-heat the fuel. Your water that you saw on the carb bolt was more than likely condensate from the exhaust leaking up thru one of the front 2 base bolts or studs.
     
  7. Jan 23, 2012
    Elvislives

    Elvislives Member

    College Station, TX
    Joined:
    Jan 22, 2012
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    That's what it was, condensation. The things i get stuck on are usually amazingly simple.
     
  8. Jan 24, 2012
    beeser

    beeser Member

    Arizona
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    Hope all are OK with a stray question but what is the part number (NAPA?) for the carburetor rebuild kit? Are they all the same for the 225 V6?
     
  9. Jan 24, 2012
    Elvislives

    Elvislives Member

    College Station, TX
    Joined:
    Jan 22, 2012
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    I'm not sure about the NAPA part number and the guys at the counter raise thier eybrows everytime I come in. I'd recommend Mike's Carburator online for the right fit. Get the number of the carb and call Mike or visit his website at http://www.carburetor-parts.com/

    The carb on my 70 CJ5 w/V6 has been replaced by a PO and I'm not sure it's the right replacement. Still you should find a 7 digit model number. My carb # is 7027089. Yours will be differant but simalar.
     
  10. Jan 24, 2012
    homersdog

    homersdog Tulsa, Ok 2019 Sponsor

    Tulsa, OK
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    The kits are available on ebay. I can get the part number when I get home from work tonight if you can't find it. Rockauto.com also has them.
     
  11. Jan 24, 2012
    beeser

    beeser Member

    Arizona
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    That would be appreciated. My '70 CJ5 is sitting in a barn out of state so I can't get to the carb. number easily. Thanks!
     
  12. Jan 24, 2012
    homersdog

    homersdog Tulsa, Ok 2019 Sponsor

    Tulsa, OK
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    Last edited: Jan 24, 2012
  13. Jan 25, 2012
    beeser

    beeser Member

    Arizona
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    Thanks homersdog!! Looks like that kit is even available at our local parts store.
     
  14. Jan 29, 2012
    Elvislives

    Elvislives Member

    College Station, TX
    Joined:
    Jan 22, 2012
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    186
    Carb Rebuild complete and ir was a good day for ol Elvis. Anyone who hesiates to rebuild this carb should rethink. It's fairly easy and there are youtube videos to help. Elvis runs great with no hesitation, smooth idle and good accelleration. The vacumm advance was also bad so that contributed to my problems. Also easy to replace.

    Installed a missing heater fresh air duct and had to fabricate an adapter for the attachment to the front grill area. Good to go with no engine smells blowing in the bucket. Now on to a zillion other special needs for the King....................
     
  15. Jan 31, 2012
    Elvislives

    Elvislives Member

    College Station, TX
    Joined:
    Jan 22, 2012
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    186
    Completed Rebuild!! Works like a charm. This was my first carb rebuild and thanks to everyone here for making it happen. The kit had everything I needed and I'm tickled pink. Plenty of power, no hesitation, great idle and no problem headed up/down inclines. Now, gotta work on a complete brake rebuild and move from there.
     

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