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ZL900 Carb needles

SteveHudders May 22, 2020

  1. SteveHudders

    SteveHudders New Member

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    Ok so I can’t buy new ones unless someone knows something I don’t.

    The original ones MIGHT still be in my carbs so how can I tell if they are OEM or aftermarket?

    Finally, I’m assuming they have notches on so you can raise or lower them. With the needle notches at the top, if the top notch in number 1, which notch is standard?

    Thanks
     
  2. Harriminator

    Harriminator Senior Member

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    If they have notches it's not orig. The ZL9-needles are made of alu and are anodized to get a hard surface, the engraved marking must be N27N (aftermarket ones are made of SS and have no marking). The carbs of the ZG1000 have the same dia (32mm) and the jets in the carbs are the same or very similar to ZL900 so it's an option to use the neddles of the Connie marked N52M or N1QM (93 hp).
     
    Last edited: May 22, 2020
  3. SteveHudders

    SteveHudders New Member

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    Ok so the original needles only have one position, you can’t raise or lower them?
     
  4. Harriminator

    Harriminator Senior Member

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    Yep.
    s-l400(12).jpg
     
    Last edited: May 22, 2020
  5. R. J.

    R. J. Supporting Member

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    :hello: You can shim the OEM needles with SS metric flat washers the same size as the wider part that meets the head.
     
  6. GaryD

    GaryD Supporting Member

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    Harminator...how the **** do you know these things????????????
     
  7. SteveHudders

    SteveHudders New Member

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    Why/when would I need to do that?

    I’m hoping the carbs have oem needles and main jets already installed when I take them off. Just a case of readjusting the mixture screws then
     
  8. Harriminator

    Harriminator Senior Member

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    I have studied mechanical engineering, option thermodynamics - piston engines was duty and my hobby...I like to go to the bottom of the matter (...and I can read lists made by other ZL-riders :laughing7:).

    YOU DON'T HAVE TO KNOW EVERYTHING, YOU JUST HAVE TO KNOW WHERE TO LOOK FOR IT. ;)
     
    Last edited: May 23, 2020
    JohnH#II, wuputt and R. J. like this.
  9. R. J.

    R. J. Supporting Member

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    :hello: Most bikes come from the factory on the lean side to pass emissions but normally do not need jetting unless you are running pods.
     
  10. paulfun

    paulfun "King Of The 1/4mi (Internally Stock)"

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    The ZL responds really well to a slight change in needle hight even without pods. I usually Dyno over 100 hp with shimmed carbs and very minor modifications to the air box.
     
  11. 87kawzl

    87kawzl Supporting Member

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    The site is lucky to have some walking encyclopedias that are active on it. Each one with their own set of experiences and memories!

    My two neighbors on opposite sides growing up both worked for Westinghouse, one a nuclear engineer and the other a machinist, the nuclear engineer stated "they don't pay you for what to know, they pay you for knowing where the information is". Very similar but different than Harri and it stuck with me.

    Another valuable bit that stuck with me is not to rely on anyone else taking care of you, you need to be able to take care of yourself. They both got laid off from Westinghouse shortly after the 3 mile island incident, the machinist was just short of full retirement and got hammered on his pension after 30+ years with them and the younger nuclear engineer had to reinvent himself because that industry was dead at the time.
     
  12. GaryD

    GaryD Supporting Member

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    :notworthy::notworthy::notworthy: To the lot of you.:icon_salut:
     
  13. R. J.

    R. J. Supporting Member

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    :hello: PAUL: What kind of mods did you do to the air box. I was thinking of installing the one inch round UNI filters. If I do where should I put them.
     
  14. paulfun

    paulfun "King Of The 1/4mi (Internally Stock)"

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    Mostly enlarging the hole in the rear and just putting some extra holes in it back when I was poor.
    For some others and even a member here we used the uni filters like you are thinking of. I would almost need to see the air box to show you where we made those holes. The main thing to figure out is you need about as much area as the filter door opened up and not to create cross flow inside. Nothing on the front.
    Check for a member yellow bird on here as his was the last one I did and we used the uni filters on that one also.
     
  15. R. J.

    R. J. Supporting Member

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    :hello: PAUL: Thanks: I'm going to start a air box thread.
     
  16. R. J.

    R. J. Supporting Member

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  17. SteveHudders

    SteveHudders New Member

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    Forgive my ignorance, what with me being a noobie and everything, but what is the point of putting separate filters inside the air box?
    If you’re going to use the oem airbox surely just a hi-flo panel filter would be better
     
  18. R. J.

    R. J. Supporting Member

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    :hello: I have 2 K&N filters for my ZL 10 and both was free. :notworthy:. They was given to me by fellow members. Adding 4 one inch in diameter mini filters will let even more air into the carbs but now I decided not to install them in my ZL 10s air box.
     
  19. paulfun

    paulfun "King Of The 1/4mi (Internally Stock)"

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    A fancy filter won’t get you anything more than the stock filter does, heck I have Dyno sheets that actually show a loss of power with the K&N filter when tested back to back with a stock filter.

    The limiting factor with the factory set up is the flow of the airbox, not the filter.
     
  20. SteveHudders

    SteveHudders New Member

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    So what’s the best way of improving the flow of the air box ?
     

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