as Nekro said you should have a brass screw that is on the left side of the carb, this is air/fuel screw. than on the right side of the carb there should be a knob with a spring under the knob. this is your slide height adjustment. you will want to set the slide height to maybe 2.5-3mm open using the adjustment knob only, you adjust the idle with the air fuel screw. you may have to adjust the slide height just a tad to dial in YOUR motor. its just a starting point. you do not want your slide more open than 4mm. shouldnt have to be that high. your bike seems to be idling pretty fast.

also you are going to want to go buy youself some jets man. your gunna want to start with a 350 main and i would imagine a 30 pilot. buy youself a bunch of jets 350,340,330,320,300 for mains and maybe like 3 pilots 32.5,30,27.5 maybe. your going to need the jets unless you only ride in say 80 degree weather. but here in wisconsin i have 100 degree summer days and in winter i have 20 below zero. so i have jets from 540 all the way to a 440. and numerous pilots.

dont blow your motor and richen that thing up.
brand new plugs are a must when tuning a new carb. keep in mind if your running just a little bit to lean your bike will run better than it ever has right before something bad happens.