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Thread: Weber 32/36 carb query

  1. #1
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    Weber 32/36 carb query

    Hi guys – I have a Weber 32 26 carb on a 2 litre Pinto, and it works brilliantly, except for hot tickover.

    It’s a new carb, the automatic choke version. It was set up by a professional, who has sadly moved on from this area.

    The problem is thus:


    • The engine starts and runs well until hot
    • When hot, it either ticks over so slowly it conks out, or revs hard, depending on how the throttle cable is adjusted. Thus the slow tickover is determined by the throttle cable, rather than the carb
    • The throttle cable is a little sticky (despite oiling/ greasing and new ultra strong springs at the pedal and carb ends, but it’s not a perfect world) – and so the tickover varies from trip to trip


    What I would like to happen is for the engine to tick over because of the carb settings, and not the vagaries of the cable.

    ….Ie when left alone with a slightly slack cable, the engine will tickover, then – when the throttle is depressed – it will kick in.

    The pic here:

    [/URL]

    … is borrowed from another forum (SO PLEASE IGNORE TE RED CIRCLE, just the screw in the black box), but illustrates what I would like to know:

    Is the screw in the black box the (hot) idle speed screw – and, if so, as pictured here, why does it not engage with the lever to its left (which moves as the throttle is moved, and so should (I think!) determine the slow throttle).

    All help gratefully received.

    Thanks J

  2. #2
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    Looks that's the idle speed stop for when the carb is off choke. I don't see the point in asking or wondering why it looks like it looks in an internet pic!

    Get a new throttle cable! Or if you don't wish to do that set it up with the throttle cable disconnected, you'll at least then know that the vagaries are down to the (tempera)mental throttle cable (or maybe the owner? )

    Chris
    Bumper sticker - This is an historic vehicle and only has three speeds....... if you don't like this one you sure as hell won't like the others.

  3. #3
    NSRA member kapri's Avatar
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    The auto choke is keeping the normal idle setting off the stop in that picture. Slack cable isn't good but if you take it off the carb should still idle fine under it's own controls.

    Firts ensure timing is correct , points gap etc etc.

    Start the engine and warm to normal temp and look at that screw position , back it off until it doesn't touch the spindle extension then screw it back in 1.5 turns. You should be idling around 750 rpm.

    Find the idle mixture screw and counts the turns to screw it LIGHTLY in to its stop . Back it out 1.5 turns and restart the engine .It should all be fine .

    If it isn't then screw the idle MIXTURE screw out 1/4 turn . It should idle better and faster ,now readjust the IDLE screw to get a reasonable tickover ( around 750 rpm.

    You can also try turning the screw IN from its starting point but it should make it worse.

    If you hav eto screw it out more than about 2.5 you've got a problem or incorrect jets etc fitted.
    Galations 6:7

  4. #4
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    Hi guys and I should have realised the choke setting was on (not just in the borrowed internet pic, but on my real life carb), and hence the gap.

    Huge thanks, and I'll do all of the above

    Edit update: Adjusting the screw did the trick

    And on...

    Get a new throttle cable! Or if you don't wish to do that set it up with the throttle cable disconnected, you'll at least then know that the vagaries are down to the (tempera)mental throttle cable (or maybe the owner?


    .. Yes, a human issue here, but with the previous owner - I didn't want to confuse things, but the main "binding" problem is in the misalignment of the accelerator pedal, as the cable comes into the cabin through the firewall then turns 30 degrees downwards to meet it. Thus, despite oiling/ greasing the cable, it's still slightly binding (and will eventually fray).

    The query above was designed to 1) achieve a temporary fix while I get the pedal re-aligned (not as easy as it sounds - don't ask) and 2) establish how to get the tickover achieved through the carb, rather than the cable, in any event, for which many thanks.

    BTW, despite the 30 degree bend, the cable is not frayed, and it drives perfectly safely but - again - does need fixing, and the cable replacing. This is now scheduled.
    Last edited by FordA; 11-08-18 at 09:44 AM.

  5. #5
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    Quote Originally Posted by FordA View Post
    Hi guys and I should have realised the choke setting was on (not just in the borrowed internet pic, but on my real life carb), and hence the gap.

    Huge thanks, and I'll do all of the above

    Edit update: Adjusting the screw did the trick

    And on...



    .. Yes, a human issue here, but with the previous owner - I didn't want to confuse things, but the main "binding" problem is in the misalignment of the accelerator pedal, as the cable comes into the cabin through the firewall then turns 30 degrees downwards to meet it. Thus, despite oiling/ greasing the cable, it's still slightly binding (and will eventually fray).

    The query above was designed to 1) achieve a temporary fix while I get the pedal re-aligned (not as easy as it sounds - don't ask) and 2) establish how to get the tickover achieved through the carb, rather than the cable, in any event, for which many thanks.

    BTW, despite the 30 degree bend, the cable is not frayed, and it drives perfectly safely but - again - does need fixing, and the cable replacing. This is now scheduled.
    If its of use once you fix that issue:
    Not sure how old the carb is, but i bought a new one recently, for same engine, and changed the primary mainjet from 140 as supplied, to 135, runs fine & idles ok

    Sent from my K013 using NSRA mobile app

  6. #6
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    Thanks, Tylf33! Will bear this in mind if any issues.

    The only niggle (having simply adjusted the idle screw so it holds the throttle slightly open and ticks over OK, taking over from the cable) is that the engine now spits back a bit through the carb when switching off the ignition. Nothing else adjusted - no mixtures, no nothing.... How can this be when nothing else has been touched?


    UPDATE - After adjusting the screw, the tickover was set a tad too fast, so the engine wanted to run on when the ignition was switched off. I slowed this down and now there is no more spitting and all issues are solved. Thanks to all posters.
    Last edited by FordA; 05-09-18 at 10:24 AM.

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