It's the cable that moves the derailleur, so you should make the adjustment and then shift it to see if the adjustment helped. It's quite possible you could adjust the high limit screw and it doesn't make an obvious difference because the cable isn't moving the derailleur far enough for it to hit the limit. You can do the shift manually (by pulling on the cable or pushing the derailleur cage) to be sure to hit the stop.

Quote Originally Posted by Velocivixen View Post
Oh, the reason I had to look it up online for additional help is because when I turned the high limit screw I didn't really see the derailleur cage move inboard or outboard.