Carby longer needle opposed to a shorter one

Discussion in '2-Stroke Engines' started by scottdoe2011, Oct 21, 2016.

  1. scottdoe2011

    scottdoe2011 New Member

    What would be th difference in them? Would one run better than the other??

  2. crassius

    crassius Well-Known Member

    each type is matched to the needle jet in operates in - it looks like a plain brass tube, but contains the pinch point that is controlled by the taper of the needle

    swapping the needle or needle jet between carbs usually results in a non-functioning carb
  3. scottdoe2011

    scottdoe2011 New Member

    What if the taper is the same but the needle is longer? Would that be a higher rev or a will it flood or what will happen??
  4. butre

    butre Well-Known Member

    longer needle means leaner part throttle and more throttle travel before you get to full throttle jetting
  5. jaguar

    jaguar Well-Known Member

    stock bikes are jetted too rich (NT carb) so a longer needle might work well at leaning it out.
  6. crassius

    crassius Well-Known Member

    I've never seen good results of mixing carb parts, but one might get lucky and hit on an improvement.
  7. Tim Bailey

    Tim Bailey New Member

    I've switched to a longer needle to lean it out for the mid range. I was at the last clip slot on the shorter needle and this gave me another notch to the leaner.
  8. scottdoe2011

    scottdoe2011 New Member

    Which position notch will give me a faster rev?
  9. zippinaround

    zippinaround Active Member

    How'd that work out? The only thing I've noticed about the needles is some have 4 notches others have 5 , must compare them more closely see how much they vary . Did your longer needle have 5 notches and short one 4?
  10. Tim Bailey

    Tim Bailey New Member

    I think the same amount of notches, one is about an 1/8" longer. Like Jag said, these engines are rich from the factory. By dropping the needle I was able to get a smoother engine at mid speeds. But frankly, I just bought a "Dollorto Type" carb on ebay. Although I've not dialed it in completely the top end is much better than I was able to get out of the NT Speed Carb. Mid range is smoother as well.