Changing needles

Discussion in 'Engine, Fuel and Exhaust' started by jaxdwg, Dec 24, 2010.

  1. jaxdwg

    jaxdwg Active Member

    209
    28
    3
    I put in an N65c needle in order to stop the cough at slower speeds and throttle twist. Well now I know what the difference is. The stock needle has a thicker body and a longer taper than the n65c. the 65c caused it to burble at light throttle settings and it ran too rich (34mpg). I went back to the stock needle and put in 1 thin washer and now I get a more stable rev through the range and I get 40 mpg now when off the freeway. Haven't checked freeway speed mpg yet. Just a heads up for the gear heads, Merry Christmas
     
    1 person likes this.
  2. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

    8,176
    98
    16
    The Keihin CV carb has been on HD's since the 80's and had plenty of time to get it right as you found out and will track well with Stage I upgrades and modest Stage II just fine. It is in the Self Help sectionl...

    CV Carb Needle Comparisons - Harley Davidson Community
     
  3. jaxdwg

    jaxdwg Active Member

    209
    28
    3
    Hey NEWHD74FAN; Is it true that unscrewing the idle jet makes it leaner?
     
  4. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    5,279
    133
    157
    If you take the idle mixture screw all the way out you will see that there is a tapered needle on the end of the screw it allows more or less fuel through the jet depending on how far out of the jet the needle is so the further out you screw the needle the more fuel is allowed through the jet although the jet is feeding at all times adjusting the screw only affects the idle mixture

    Brian
     
  5. Jack Klarich

    Jack Klarich Expert Member

    18,544
    153
    399
    And I might add not too far they will loosen up and I have seen them back out:s
     
  6. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    5,279
    133
    157
    The spring is there to hold them tight so between 2 and 3 turns out is usually a good point to start with if it is out too far and not enough spring tension they will as jack said work themselves out and fall by the wayside

    Brian
     
  7. jaxdwg

    jaxdwg Active Member

    209
    28
    3
    Does UNscrewing it make it richer or leaner? It seems that mine gets leaner as I unscrew it
     
  8. Jack Klarich

    Jack Klarich Expert Member

    18,544
    153
    399
  9. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

    8,176
    98
    16
    Jack has you covered, richer...but the key is to seat it inwards lightly then back out 1 1/2 to 2 turns to start. I like it "lean best plus 1/2 turn...and used 2 #4 washers underneath the stock needle as Glider's tip suggested...works like a champ!:s
     
  10. jaxdwg

    jaxdwg Active Member

    209
    28
    3
    Thanks Jack and NEWHD74FAN That was what I was looking for. If I screw it in the bike runs so rich I can see the black of the exhaust. I unscrewed it about 3 turns and she smoothed up and idled way fast so I re-set the idle speed and it is purring like a kitten now. I have the #46 idle jet---yeehaa-----jack