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<img src='content_image/542054.jpg'>

Next, adjust the throttle control so that it has a slight cushion action at two positions on the throttle quadrant: one when the carburetor throttle valve is in the full-open position and the other when it is closed to the idle position (stop to stop). 

Adjust the cushion by turning the cable turnbuckles equally in opposite directions until the throttle control cushion is correct at the full-open position of the throttle valve. Then, when the throttle arm stop is adjusted to the correct idle speed setting, the amount of cushion should be within tolerance at the idle speed position of the throttle valve. The presence of this cushion ensures that the travel of the throttle valve is not limited by the stops on the throttle control quadrant, but that they are opening fully and closing to the correct idle speed as determined by the throttle arm stop. 

Adjustment of the engine controls is basically the same on all aircraft regarding the linkage adjustment to a predetermined length for a specific setting of the unit to be controlled. Then adjust cables, if used in the control system, to a specific tension with the control system locked. Finally, the full travel of the unit to be controlled is ensured by establishing 

the correct cushion in the controls. In general, the same basic procedure is used to connect the linkage of the remaining engine controls. After rigging the engine controls, safety the turnbuckles and castle nuts, and make certain the jam nuts on all control rods are tightened. 

On multiengine aircraft, the amount of cushion of all engine controls on each quadrant must be equal so that all are aligned at any specific setting chosen. This eliminates the necessity of setting each control individually to synchronize engine operations. 

After the engine has been installed, it is necessary to adjust the cowl flaps, if installed, so that the passage of the cooling air over the engine can be regulated accurately. Operate the system and recheck for opening and closing to the specified limits. Also, check the cowl flap position indicators, if installed, to ensure that they indicate the true position of the cowl flaps. Cowl flaps are doors at the bottom of the rear cowling that are used to control air flow through the cowling. 

