How do you adjust the idle not choke 1989 Suzuki 450 motorcycle - revs high in neutral?

on left hand side theres a nob if i had a picture i would put it on here but im @ school so i cant take a picture right now. i can later. but anyways you look for a nob that's on the left side of the bike if you are sitting on it. you want to start the bike and turn the nob rev it up and see how it runs. if it runs to fast turn it back if it stals turn it forward. you want to adjust it rev it up and then turn it off to see how itl start back up and stay running. you can email me @ kurtis3233@Yahoo.com if you want a picture display of the nob or any other help