This loooks like a larger sized plane so you are most likely not a novice. I ask that because I don't know if you used metal to metal linkage on the throttle, nor what the throttle connection is at the engine. It does not show on your first set of pictures. But, that rod you showed in your last picture looks like metal. That's ok on the servo end because the servo arm is not metal, but I don't see what's on the other end, on the throttle arm itself. If you are using metal, Zbend for instance, you might want to reconsider using something like the Dubro Safety Link clevis or a ball-link arrangement that is non-metalic. You may have already done this, but by the picture, we can't tell. The metal to metal junction at the engine can cause inteference from vibration.

CGr.