We're gonna need just a few more details here, like the brand of EIII, the size, the kit, etc.

Size DOES make a difference here.

High/low rates? They are set up in the transmitter programming to allow one amount of control throw on one rate and another amount on the other rate. Usually high rate is more throw, while low rate is , well, less throw. It is set up for each flight surface channel, like it says in the manual.

You did read the manual, didn't you?

While you're in the reading mood, how about glancing at the book that came with your EIII. Maybe it has something about control throws in there somewhere.

They usually do....