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Thread: Cotten ! - linkert differences

  1. #1
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    Default Cotten ! - linkert differences

    Linkert used .187" and .240" low speed holes.
    On the large hole the lever follows the choke cam when the choke is closed.
    On the small hole the lever only follows the choke cam part way.
    Same cams, is this normal ?


  2. #2
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    1950Panhead!

    Curiously, 1" Model Ms had a .248" 'idle well hole', .001"

    Generally, 1" models were .186"-.187", and 1" models were ~.240". However, I currently have a couple of M-35s on the bench either way, proving once again there is an exception to every rule.
    (Why were Indian 1" models the smaller bore? And another mystery is why for late M74B productions did they "choke" the well down to ~.120" for the bottom inch or so?
    It only adds to the mystery that the bores were always produced just shy of a nominal drill size.)

    As best I can eyeball from what I have on the bench, all three sizes of Model Ms' lift levers "follow the choke cam" in the same arc, even the 1" model with a different lift lever.

    What am I missing?

    ....Cotten
    PS: The various spring collars over the well were air metering orifices.
    They must slide with the action of the lever, however so slight. Their hole should be inspected for oval wear, and the LS needle should be observed for wear against it.
    The variety of collars is worth study, as they have mysteries of their own.

    PPS: After guessing that your carb on the left might be an M-75, I pulled one of them off the wall, and sure enough, it is another 1" model exception with a large idle well bore.
    But everybody swears Linkerts are "simple", right?
    Last edited by T. Cotten; 06-02-2017 at 05:07 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  3. #3
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    Cotten !
    The larger hole allows the needle to tilt more which allows the lever to follow the cam.
    The smaller hole restricts needle tilting so lever does not follow cam.
    I have M16, M18, M35, M51,M75 with .240" hole
    I have M35,M61,M74,M74 with .187" hole.
    Photo lever on cam with choke open.


  4. #4
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    Left carb - lever does not follow cam (.187" hole)
    Right carb - lever follows cam (.240" hole)


  5. #5
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    1950Panhead!

    T'ain't the hole. Too many tens o' thousands of them work...

    Something else is binding it.
    (Honestly, I never even attempt an assembly until it has all been cleaned and thoroughly prepped; It saves tail-chasing. That ain't a Tiaranian lift lever, shown on the right in the attachment, is it?)
    If the needle is hitting the side of the hole, that's not good either.

    Make certain the hole in the casting for the shouldered bolt isn't skewed up. (I remember a poorly-installed helicoil doing something like that.)

    ....Cotten
    PS: I have (at least) three 1"ers on the bench with a fatter well hole.
    And they are liable to sit here until somebody reproduces an accurate lift lever! (Like on the far right in the second attachment, but I could use Scheblers like on the left as well..)

    PPS: Since your hardware doesn't look prepped, please make certain the knob spring is on top of the needle and not beneath it. That would certainly reduce its angle of 'play'.
    (Any stone unturned hides something to bite you.)

    PPPS: You can guess now why I can't staff my shop!
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    Last edited by T. Cotten; 06-02-2017 at 12:47 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  6. #6
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    Cotten !

    Thanks for responding to my post.
    Some pondering then eureka, spring on top (others are confused).
    I posted on caimag yesterday but no wise men came forward.
    I was laying in bed last night with visions of linkert parts dancing through my head when I remembered you and caimag parted ways.

    Jerry
    Last edited by 1950Panhead; 06-02-2017 at 03:14 PM.

  7. #7
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    Don't feel bad, 1950Panhead!

    I have received Tiaranian lowspeed needle assemblies fresh in the bag with the spring beneath the needle.
    (Wrong spring too.)

    ....Cotten
    PS: You will find little evidence that I ever had anything to do with caimag. Wish there was zero.
    Last edited by T. Cotten; 06-02-2017 at 04:39 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  8. #8
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    I am not knowledgeable about Linkert carbs at all, but I sure would like to be. I kind of always liked tig welding copper and bronze metals.

    I use to have to weld beryllium copper quite a bit. I remember getting beryllium copper poisoning from wire EDMing the nasty stuff. At first I thought I just had the flu. My mouth tasted like a penny for a week after I finally felt better.

    You guys, who work with these worn out carbs, must have some really neat tooling and fixturing.
    Last edited by ryan; 06-04-2017 at 04:25 AM.

  9. #9
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    Talk about being slow to the trigger, now I see and finally understand what you all were talking about on what was missing and different about my M53 carb because it does not have these parts.

    So if I am understanding this correctly, applying the choke not only shuts down the air, but it also enriches the fuel as well.

    My reply was not intended to hijack nor sway the conversation, I just had a light bulb moment.
    Last edited by ryan; 06-04-2017 at 05:17 AM.

  10. #10
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    Ryan!

    The choke mechanism design of 1" DLX Scheblers was incorporated upon almost all production Linkerts, with the exception of yours (and before I get ragged at.. the "barrel" racing series).
    The choke control tab with a detente in several positions actuates a shaft with a choke disc, and a cam to move the lift lever.

    When the disc is closed, the lift lever lifts the LS needle high from its seat allowing a larger volume of both air and fuel to the idle gallery as it is pulled into the choked carb bore by the motor when kicked. Please note that there is a spring collar beneath the spring that lifts the lever, and the hole through which the needle passes is an orifice to meter air into the idle well.

    Linkerts are so simple yeah right.

    ...Cotten
    PS: My TIGmeisters usually made a mess for me to clean up. So I rely on much more friendly silver solder.
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    Last edited by T. Cotten; 06-04-2017 at 01:11 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

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