carb tuning help, 1988 cr125..

[mopower440]

After 12 years of no bike, i decided i wanted another 2-stroke just to play in the field with, found a 1988 cr125, i bought it cheap enough. I pulled the carb and cleaned it and the jets out. Now, this is a flat slide carb, the only screw adjustment on the outside of the carb is a small flat blade screwdriver adjustment toward the rear of the carb really close to where the airbox mounts to the carb. now, what does this adjustment control and whats the baseline setting?
next, the needle adjustment on the slider is for WOT, correct?
thanks!

 

[wornknobby]

first off, the flat head screw on the outside is an air adjustment screww to fine tune your low ciurcuit. if you need to turn it out more than 3 turns you deffinatly need a different piolet jet. in is richer and out is leaner,

and no, the needle in the slide is for like 1/4 to 3/4 throttle

 

[TimberPig]

Carb Tuning


Here is some reading that will help you out.

 

[mopower440]

first off, the flat head screw on the outside is an air adjustment screww to fine tune your low ciurcuit. if you need to turn it out more than 3 turns you deffinatly need a different piolet jet. in is richer and out is leaner,

and no, the needle in the slide is for like 1/4 to 3/4 throttle

ok, you say the screw is to fine tune the low circuit, does that mean idle and off idle? I turned it to 1 1/2 turns out to make it idle nice, is that ok?

 

[wornknobby]

that is perfect, you want to turn it out 1 /12 turns to make it idle good, this means your idle curcuit is jetted pretty good.

if you have to turn it out more than 2 to 2 1/2 turns you would need to make the piolet jet leaner, and it you need to run it in all the way you would need the next size smaller jet.

 

[mopower440]

cool, but how do i get this screw set the best i can, do i go by the idle itself or if it burbles off idle or what..?

 

[wornknobby]

ok well you don't want it to bog off idle from applying throttle, but there are also other cicuits that over lap themselfs. read the sticky on the top off this page for a jetting link, it very helpful.