I think on the '89 you have to turn the choke clockwise and the idle will go up. Honda had it in the choke that year. By turning in the choke, I believe it richens the mixture and raises the idle. BTW, turning it countewrclockwise lowers the idle.
Definately set it by ear and then ride it. You don't want it so low that it stalls in a turn and you don't want it too high so that it pulls you through turns. That is how I set it. Nothing magic about it.