You sure that high idle isn't the engine racing from being a bit too lean?? pull the choke for a second and see if it drops. You could also look in the intake and see what height the slide is sitting at, or remove the slide and check the action of the grub screw for the idle speed. I also recall some intial wear on the slide where it stops against the screw. Double check this hasn't got too much burring on it. A good tip is to lift the slide (open the throttle a bit) when making idle adjustments, as it takes the weight off the slide.