GREAT PLANES Super Stearman Instruction Manual page 21

4. Drill a 3/16" [4.8mm] hole through the firewall in line
with the throttle arm on the carburetor.
5. Locate the 24" [610mm] gray plastic pushrod tube and
cut it 12-3/4" [324mm] in length. Sand one end of the tube
with 220-grit sandpaper. Insert the tube into the firewall.
Glue the roughened end of the tube flush to the firewall.
6. Place your throttle servo into the servo tray as shown.
Drill a 1/16" [1.6mm] hole through each of the mounting
holes. Remove the servo. Then install and remove a servo
mounting screw into each hole. Apply a couple drops of thin
CA into the holes to harden the threads. When the glue has
cured permanently, mount the servo to the servo tray.
7. Cut the 1" [25mm] threaded end from the .074" x
17-1/2" [445mm] throttle pushrod wire. Install the wire into
the tube and attach it to the servo horn arm with a Faslink.
Use the same technique used for the ailerons.
8. Attach the pushrod wire to the throttle arm with a brass
screw-lock connector, nylon retainer ring and a 4-40 x 1/4"
[6mm] socket head cap screw.
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