Okay, so I've got my new pipe on Uni filter installed and carb jetted (dynojet). The only thing I can't figure out is how to adjust the fuel mixture. The Dynojet instructions say to adjust 2.5 turns out from lightly seated. Now the 250 idles real roughly and I have to keep restarting it until warmed up. I used a mirror to look at the fuel mixture screw, but can't tell what kind of tool is needed. Any help/advice would be much appreciated.

Thanks