It's not the engine mounts that need to be adjusted. It's your throttle linkage. What you ideally want is a smooth, linear opening of the carb as you advance the throttle. Use the differently spaced holes on both the servo arm and the throttle arm to come up with the right amount of throw. Adjust the length of the pushrod as needed. Once you get it as close as you can mechanically, you'll then adjust with the travel adjustments on the radio.

A lot of times these sorts of things can be explained easier in person. Whomever is helping you should be able to assist you right out at the field, and you'll have the whole thing done and behaving properly in about five minutes.