5
You should also notch the vent tube with a small file to provide
for continued air flow should the tube come into contact with the
top of the tank.
Make sure the bends to the vent tubes applied at the factory
have not restricted airflow to any significant extent. Also, check
the Tygon for any nicks or cuts and secure to the tubing with
wire ties before re-assembly.
Reassemble and mark the tank for vent and fuel for later
reference.
Once the tanks are back together, they should be leak checked
before installation in the aircraft. Connect extra lengths of fuel
tubing to the fuel and vent lines and submerge the tank in
water. Pinch off one line and gently pressurize the tank by
blowing into the other, looking for signs of air bubbles. If the
tank shows evidence of air leakage around the vent cap, tighten
the Philips head screw and check again. If you have a stubborn
leak, you can re-tap the inner plate for a slight larger 6/32 cap
head bolt.
Step 3: Tank Installation
photo 3 – lower foam support
Re-attach the Tygon tubing to the main saddle tanks. Make sure
the lines are of equal length. Exercise care not to break the
tanks while fitting the Tygon. Slowly wiggle the tubing into
place. Wire tie for security.
Cut a scrap piece of fairly stiff foam 3” x 5” x ½” and secure to
the bottom of the fuse at the rear of the saddle tank bay with a
few drops of thin CA (
photo 3
).
Insert the saddle tanks into position, slipping the Velcro hold-
down strap into place as you do.
Cut another piece of scrap foam 2” x 3” x ¾” and slip it between
the saddle tanks at the bottom of the fuse.
Cut two pieces of scrap foam 2” x 3” x 1” and secure these to
the sides of the fuse at the rear upper corner of the tanks with a
few drops of CA to provide added support (
photo 4
).
photo 4 – side foam support
You will need to make two center tank supports from scrap ply. The
tank needs to sit far enough back from the cockpit for fuel lines to
clear the back of the main hatch area. It also needs to incline
slightly from rear to front to insure adequate clearance for the
engine hatch.
Temporarily position the lower engine bypass on the mounting
rails.
Slip the intake extension into place and secure with the aft
Velcro strap.