Your reverse servo isn't traveling enough. It's simple setting change on the transmitter. I'll post a link to how to do it in a second.

Edit: All you have to do is adjust your EPA. Here's the manual and go to page 4 as I feel it best explains how to do it:[link=http://jrradios.com/ProdInfo/Files/jrp317275-manual.pdf]http://jrradios.com/ProdInfo/Files/jrp317275-manual.pdf[/link]