GREAT PLANES Extra 300S Instruction Manual page 8

9. Cut the covering from the front edge of the fuse for
the cowl mounting blocks and glue them in position.
10. Reposition the cowl on the fuse and mount the
spinner to your engine. Align the cowl with the spinner and
the fuse and tape it in position. View the cowl carefully to
make sure the cowl is centered horizontally and vertically
on the spinner.
11. Drill a 5/64" (or 3/32") hole through the cowl and one
of the cowl mounting blocks. Screw a #4 x 1/2" SMS (sheet
metal screw) through the cowl just far enough into the cowl
mounting block to temporarily hold that part of the cowl in
place. One at a time, drill a hole and insert a screw into the
remaining three cowl mounting blocks the same way.
12. Remove the spinner and cowl. Roughen the inside
of the cowl around the four screw holes with 80-grit
sandpaper. Cut four 1" pieces from the strip of glass cloth
and glue them to the inside of the cowl over the mounting
holes with 30-minute epoxy as shown in the photo. Set the
cowl aside while the epoxy cures. Use a small amount of
epoxy to fuelproof the cowl mounting blocks.
13. Mark the firewall where the throttle pushrod guide
tube will enter. This location may vary depending on your
engine. Make sure the guide tube will not interfere with the
fuel tank. Ideally, the hole should be 3/16" above the
bottom edge of the firewall so it can rest on top of the fuel
tank floor behind the firewall. Drill a 1/8" hole through the
firewall for the throttle pushrod guide tube.
14. Drill a 1/8" hole through the former where shown in
the photo. Roughen the outside of the guide tube so glue
will stick, then insert the throttle pushrod guide tube
through the firewall and the former. You will cut the guide
tube to the correct length when you install the servos.
15. Cut the clear pick up tube included with this kit to a
length of 2-7/8". Assemble the fuel tank as shown in the
sketch using the straight nipple. After you assemble the
tank hold it up to the light and make sure the clunk does
not contact the rear of the tank. If necessary, disassemble
the tank and shorten the pick up tube.
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