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tuning stock carb

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  • tuning stock carb

    does n e one kno how to adjust the carb for max performance on a stock carb?

  • #2
    if you had a dyno it would be a breeze, but of course we ain't that rich or is it so?

    anyway, what kind of pb do you have? a 40cc aka 47cc or the 49cc aka x1/2 variant? when i had my stock carb on my 40cc there was only one needle adjustment, i did a 2 turn adjustment then ran the bike and did 1/16 to 1/8 adjustments to tune it more. (this depends on your bike, the conditions (cold hot etc), and the type of fuel and ratio you use.) im using a 40:1 ratio for daily riding, and 50:1 on racing. btw, also, when you change your gas ratio, you still have to tune the carb again for max performance.

    another quick performance gain is to gap your sparkplug to around .030, this increases spark energy therefore lighting the air/fuel mixture better. i'll go in to details about ignition on my site soon.

    hope that helps


    • #3
      yeah i have a 49cc thanks alot but juss wanted to know how much to turn the needle out from closed for the best performance. and i've been running 25:1 ratio but imma start using 40:1 ratio...what do you think?


      • #4
        start from 2 turns open, ride... turn 1/16-1/18 open ride till you feel a slight WOT bog. then turn close 1/16 increments till the bog goes away. right when the bog @ WOT goes away, you are running mild-rich. from there, your can lean it out a bit (prob 1/16 more closed) then you should be set.

        the only way you will really see the performance is on a dyno, that is the only way you can see the actuall hp numbers based on tuning the carb.

        mine is case-induction oriented, meaning that the A/F mixture goes inside the case and into the cylinder, the more saturated ratio of air and fuel is best, yet again, all motors are different.

        hope that helps, tune well!