air box mod.

Discussion in 'Dakar champion (950/990)' started by vgstef, May 26, 2004.

  1. vgstef

    vgstef Been here awhile

    Joined:
    Aug 28, 2003
    Oddometer:
    197
    Location:
    Canada
    I just did the ait box mod (sommer) and raise the needle on the carburator and after this mod i am having surging problem at 3000-4000 RPM. Anyone experiance this ? should I put the needle back to the original positon ?
    #1
  2. mchaskell

    mchaskell Adventurer

    Joined:
    Apr 21, 2004
    Oddometer:
    70
    Location:
    Fresno, CA
    Did you turn out your air screws? Part throttle operation is a matter of float height and the pilot jet. I would turn out the pilot air screws 2.5 - 3 turns and see how she runs.
    #2
  3. vgstef

    vgstef Been here awhile

    Joined:
    Aug 28, 2003
    Oddometer:
    197
    Location:
    Canada

    Yes when I lift the needle (1 clip) I also ste the idle screw to 2.5 turn out front and rear. The original setting was 1.3/4 front and 2.1/4 rear.I thing I will put the Idle screw back to the original position.
    #3
  4. Renegade6

    Renegade6 Been here awhile

    Joined:
    Feb 23, 2004
    Oddometer:
    854
    Location:
    New Boston, TX
    Make sure your carb vent tubes (goes from each carb to the bottom of the airbox) aren't kinked.
    #4
  5. KTMax

    KTMax Ninth of the Nazgul

    Joined:
    Oct 28, 2003
    Oddometer:
    1,099
    Location:
    Amsterdam, The Netherlands
    Yep AND if they are the uprated version of the hoses (depending on the production date of your bike)...
    #5
  6. vgstef

    vgstef Been here awhile

    Joined:
    Aug 28, 2003
    Oddometer:
    197
    Location:
    Canada
    The vent tube for the carb are venting to the outside of the airbox. Both carb venting hose still connect with the Y connection and then the hose exit the airbox and at the end of the hose I installed a crankcase filter. Should I disconnect the Y connection and exit both hose to the outside of the airbox ?
    #6
  7. Flanny

    Flanny Flanny-it-up!

    Joined:
    Feb 18, 2003
    Oddometer:
    2,739
    Location:
    Ottawa, Ontario, Canada, the World, the Universe

    You should be fine with the "Y". Just make sure there are no kinks.

    BTW - with the air-box more open, it is impossible that your bike should be at the stock idle jet adjustment. There is more air, and therefore, there needs to be more fuel.
    #7
  8. Renegade6

    Renegade6 Been here awhile

    Joined:
    Feb 23, 2004
    Oddometer:
    854
    Location:
    New Boston, TX
    Try running it without the crankcase filter.
    #8
  9. Flanny

    Flanny Flanny-it-up!

    Joined:
    Feb 18, 2003
    Oddometer:
    2,739
    Location:
    Ottawa, Ontario, Canada, the World, the Universe
    #9
  10. vgstef

    vgstef Been here awhile

    Joined:
    Aug 28, 2003
    Oddometer:
    197
    Location:
    Canada
    I remouve the carb and set the idles screw to 1 7/8 for the front and 2 3/8 for the rear. The original position was 1 3/4 front and 2 1/4 rear. This set up work good the flat spot is gone. I also try 2 1/2 for each carb and the bike did not like it.
    #10