Motorcycle Carb - Whats this

Discussion in 'The Guru's Pub' started by dk_lightning, Mar 2, 2012.

  1. dk_lightning

    dk_lightning Ancient Guru

    Messages:
    1,528
    Likes Received:
    56
    GPU:
    GTX 1070 8GB
    Whats this screw for?

    [​IMG]

    Ive not got a clue. Its not for idle speed or fuel/air mix
     
  2. scheherazade

    scheherazade Ancient Guru

    Messages:
    2,051
    Likes Received:
    0
    GPU:
    fullHDs
    Can't speak for that carb...

    But the typical suspects could be :
    idle
    low rpm mix
    high rpm mix

    But since it's not one of those...


    Does it connect to anything?
    Have you tried unscrewing it all the way to see what's on the other side?

    -scheherazade
     
    Last edited: Mar 2, 2012
  3. dk_lightning

    dk_lightning Ancient Guru

    Messages:
    1,528
    Likes Received:
    56
    GPU:
    GTX 1070 8GB
    ill upload a pic, 1 sec

    Ok looks like this:

    [​IMG]
     
    Last edited: Mar 2, 2012
  4. dukedave5200

    dukedave5200 Ancient Guru

    Messages:
    3,192
    Likes Received:
    0
    GPU:
    BFG GTX 285 OCX - SLI
    What motorcycle does it belong to? Short answer is it's a mixture needle valve.
     

  5. AbjectBlitz

    AbjectBlitz Ancient Guru

    Messages:
    3,462
    Likes Received:
    2
    GPU:
    R390 1200/1720
    I would guess it is a low/high rpm mix?

    Some olde bikes had to be manually adjusted dependent if you were after top speed or low down grunt. I had a old commie bike that had a weird mix like that.
     
    Last edited: Mar 2, 2012
  6. dk_lightning

    dk_lightning Ancient Guru

    Messages:
    1,528
    Likes Received:
    56
    GPU:
    GTX 1070 8GB
    Think i got it, Its the throttle stop.. what ever that is lol.
     
  7. Thug

    Thug Ancient Guru

    Messages:
    2,200
    Likes Received:
    9
    GPU:
    RTX 3080
    Its a fast idle valve, so yes a throttle stop.

    Its so you can set the idle tick over speed manually.
    Screw it in a little and the throttle will open resulting in the engine speeding up on tick over.
     
  8. dk_lightning

    dk_lightning Ancient Guru

    Messages:
    1,528
    Likes Received:
    56
    GPU:
    GTX 1070 8GB
    The screw dont even touch the throttle tho. thats the odd thing
     
  9. Thug

    Thug Ancient Guru

    Messages:
    2,200
    Likes Received:
    9
    GPU:
    RTX 3080
    It could be a mixture screw the for air/fuel.
    If not connected to anything then it will be for air.
     
  10. SpdyRobi

    SpdyRobi Active Member

    Messages:
    93
    Likes Received:
    0
    GPU:
    GTX 1070 SLI
    It appears to be your main needle valve not a throttle stop.


    EDIT: nvm main needle is in the middle not on the side.
     
    Last edited: Mar 4, 2012

  11. airbud7

    airbud7 Ancient Guru

    Messages:
    7,835
    Likes Received:
    4,744
    GPU:
    pny gtx 1060 xlr8
    ^This...Again...>What motorcycle does it belong to???
     
  12. dk_lightning

    dk_lightning Ancient Guru

    Messages:
    1,528
    Likes Received:
    56
    GPU:
    GTX 1070 8GB
    Hyosung Cruise II 2001
     
  13. INSTG8R

    INSTG8R Ancient Guru

    Messages:
    1,659
    Likes Received:
    94
    GPU:
    Nitro+ 5700XT
    Well my best guess is it's the idle adjustment screw. Mine doesn't touch either but that is only because I have adjusted my throttle cable instead.
     

Share This Page