Hangar 9 Extra 260 Assembly Manual page 33

 Step 4
Bend the longer fuel tube carefully to a 45-degree
angle using your fingers. This will be the fuel tank
vent tube. Use care not to kink the tube
while bending.

Step 5
Slide the vent tube into one of the remaining two
holes in the stopper from the tank (small cap) side.
Section 10 – Fuel Tank Installation
 Step 6
Locate the clear piece of silicone fuel tubing and
the fuel tank clunk. Cut the tubing to a length of 5".
Install the clunk onto one end of the silicone
tubing. Slide the silicone tubing (end opposite the
clunk) onto the fuel tank pickup tube (straight tube)
in the stopper.
 Step 7
Carefully insert the stopper assembly into the fuel
tank. Note the position of the vent tube; it must be up
at the top portion of the fuel tank to function properly.
Also, it may be necessary to shorten the length of
the fuel pickup tubing to make sure the clunk does
not rub against the back of the fuel tank. You should
be able to turn the tank to any attitude, and the clunk
will fall to the lowest point (all directions except for
having the stopper facing down).
33