With the engine off and the electronics on. Power on the radio and then take off the servo horn. While the servo horn is off the servo, center the radio on the throttle trim. Then take off the servo horn and put it on the servo so that the brakes are not on and the carb is slighly open. Tighten down the servo horn and you should be good to go. Just don't over tighten the servo horn. This is covered in your manual and if you need a visual, you can look it up on youtube by searching servo centering. Hope this helps, Steve.