really dumb atc90 carb questions

[ratvespa]

so I got a freebie atc90 Im getting back together for the wife, rebuild the carb tonight, 4 beers later got it done. the only thing that puzzles me is the little pull knob on the side of the carb, took it apart, it's a spring and plunger, that closes off 2 holes going to the mail and slow jet, with one hole going to the carb opening's front.

what does that knob do? none of my other atc's (185, 200x and 250r) have this.

it is pretty cool how everything is built into the carb, fuel tap and fuel filter.

[ratvespa]

and I guess I should update my signature since I don't have the 70, and no one uses myspace anymore.
also 54 post in 7 years! Im on a roll!

[MTS]

Its Supposed to be for high altitude....Like climbing a mountain... From what i remember....The higher you get the thinner the air, Need to pull it to lean it out or it runs like a dog....Need a big Diff to need it...say from 3000ft to 8000ft or so...Least thats what i seem to remember from my old one...seeing as they had a butterfly choke too.....Maybe i am thinkin of something else :beer

[shadslayer]

yeah mine has the black knob that says "pull if over 6000 Ft" i believe. I just cleaned my carb and put it back on. stupid question but which way is CHOKE ON. I'm thinking its back/up and off is down but I cant remember. HELP!!??? thanks in advance

[atc350xer]

back/up is choke on