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Thread: Dellorto Main Jet Question

  1. #1
    apriliaforum Junkie skeelo221's Avatar
    Join Date
    Jul 2011
    Portland, OR

    Dellorto Main Jet Question


    I was just gifted a '99 SR 50 and I am tearing it all down just to go through it all.
    The carb is Dellorto PHBN 12. The main jet has a "14" stamped on it but that can't be correct. Can someone help me ID this main jet so I know what size I'm starting with?

    Scoot is stock for now, I did pull the washer out from the variator. Eventually want to throw a Leo TT exhaust on it so will need to change main jet at that time

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  2. #2
    apriliaforum expert
    Join Date
    Jul 2015
    If you are planning on a project then check this compilation guide I have.

    It says 74 on it. Remove it with a tight fitting screwdriver and measure the thread diameter because dellorto does them in either 5mm or 6mm. If you need jets get the Polini ones. 10 pieces from 70-80.

    you might need to shop around for some screwdrivers that fit excellent. Pull the small one out too, the idle jet needs to be squeaky clean before you start tuning. Or replace it with a dellorto single
    --- diploma for engine repair in 2012
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  3. #3
    apriliaforum Junkie skeelo221's Avatar
    Join Date
    Jul 2011
    Portland, OR
    Hahah!! It most certainly does say 74.
    It's a little faint so I mis-read it as 14


    And I will read through your guide as well, thanks for the link.

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