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Choke Tube help on '68 KR

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by mikeljgt500kr, Feb 25, 2011.

  1. mikeljgt500kr

    mikeljgt500kr Well-Known Member

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    Having now obtained the proper C80F-9510-AB carb for my KR, I am trying to figure out the choke tubes hookups. My previous carb, a Holley 4779, had only the one, heated and insulated choke tube from the exhaust manifold to the passenger side bottom of the carb, no others. The new carb has a vacuum tube sticking out near the top passenger side of the air horn for another, long, uninsulated stainless tube to be connected, along with the screwed in fitting on the bottom for the insulated tube to the exhaust manifold. I need to know where the uninsulated upper tube connects on the engine. Thanks for any help.
     
  2. Coralsnake

    Coralsnake Well-Known Member

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    One tube fits directly into the cast iron manifold, the other tube fits into a round fitting directly below
     
  3. mikeljgt500kr

    mikeljgt500kr Well-Known Member

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  4. Coralsnake

    Coralsnake Well-Known Member

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  5. mikeljgt500kr

    mikeljgt500kr Well-Known Member

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    Wow, now that is a good idea if you have the engine out. Too bad it wasn't done when the engine was overhauled and painted by the previous owner. Guess I will try to clean it out as best I can before I install the new choke tubes. Thanks.
     
  6. Bob Gaines

    Bob Gaines Well-Known Member

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    Unfortunatly you will not be able to clean it out on the car. It is highly probable that the shredded metal filter material in the chock furnace will after 40 years have disintegrated into a solid mass and will not circulated air through it as it was designed in the two tube system. This will mean your choke system will work very poorly. The only thing you will maybe be able to accomplish is drilling out the remnants of the old tubes to be able to fit the new choke tubes. It will at least look functional and if your real lucky it may even work. Bob
     
  7. mikeljgt500kr

    mikeljgt500kr Well-Known Member

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    I blew out both ends with compressed air, and used a .38 caliber wire brush to clean up the holes into it, and vacuumed it out. Then I reseated the new choke tubes and the choke works fine. It is closed when it is cold, and opens fully when warm, so I guess it is working correctly.
     
  8. Ranger Jerry

    Ranger Jerry Well-Known Member

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    Thanks for asking this question. I went out and checked my KR and found that it did not have the uninsulated tube, the bottom hole on the stove is open and the tube port on the carburetor is capped with a rubber cap. This might explain why it has never idled properly. Now I know how to fix it.
     
  9. mikeljgt500kr

    mikeljgt500kr Well-Known Member

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    You're welcome, I find these kind of small details to be very interesting and informative. As I mentioned before, I have been away from Shelbys and '68 1/2 CJ Mustangs for about 15 years and am just getting back into them. The first time, when I had a '68 GT350 and a '68 1/2 CJ coupe, I was not so interested in the distinctions about originality and getting them to work as originals. For instance I put big Holleys with electric chokes on them, drove them around alot and didn't worry about original stuff and function. But after spending the last 10 years in NCRS judging and restoring a '66 L79 and a '67 L71 for Top Flight awards, I have come to truly prize and appreciate the original parts and function of the great muscle cars. So I may be asking more questions as I work through this new one.
     

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