Some (stock)carb tuning help!

Discussion in '2-Stroke Engines' started by JimKamenidis, May 5, 2011.

  1. JimKamenidis

    JimKamenidis Member

    first correct me if i'm wrong: the leaner the mixture the higher the idle rpm and the richer the mixture the lower the rpm.
    so in the beggining the needle was in the middle setting and the bike was running too rich, alot of exhaust oil no i moved the needle to the leaner setting out of the i found out that i was running too lean due to comparison with other videos(with same exhaust and carb!) and really high i moved to the setting between the previous two..and it's running well.
    So my questions are:1)the fact that i am running without a filter now and that i expect one high-flow to come does mean that the mixture is going to get richer..should i move to the leaner setting again?
    2)does the fact that in the middle position the mixture is rich mean that overall the main-jet is big too?so is the bike really rich and in full throttle???
    thanks. :grin5:

  2. goodtime65

    goodtime65 Member

    Yes the main jets are big so that it does run rich. Give your motor a chance to get broken in a bit before it realy starts to run good. The clip setting only only comes into affect between 1/4 and 3/4 throtle
  3. GearNut

    GearNut Active Member

    The state of richness/ leanness (is that a word?) certainly does have an affect on the idle speed. A lean burn will tend to cause the engine to idle faster, a rich burn the opposite.
    That is why there is an idle speed adjustment screw.
    Never adjust the air/ fuel ratio to correct the idle speed. The idle speed needs to be adjusted after the air/ fuel ratio has been tuned correctly.