ORIGINAL: JesseV
I have adjusted the linkage attachment points (both servo arm end and throtle arm end) for minimum travel,
Just to confirm that you have them in the right position (A lot of people get this wrong) The sefvo end should be as CLOSE to center as possible, while the throttle arm end should be as FAR from center as possible
If that is how you are set up, the next thing to do (if you want to avoid doing it electronically with the Tx) is to rotate the servo arm to a different position See below: