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The tube that the pickup line connects to inside the tank may also need to be shortened to
approximately 12 mm for ease of installation through the tank orifice. When finished, make
sure to blow out the metal fragments and clean up any sharp edges.
While the components are apart, check the Tygon pickup line for equal lengths in both saddle
tanks. They should be long enough to reach the back of the tanks without being so long as
to restrict their ability to move to the top of the tank when the aircraft is inverted.
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.
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.
It is recommended that you mount the forward fuel tank so as to be able to remove it for
maintenance in the future.
Before installing the saddle tanks, check the spar receiver bolts to make sure the nuts are
secure. Plug the wings into the spar receivers and move them up and down, tightening the
locknuts until there is no evident play.
Cut two strips of 6 mm ply approximately 180 mm long by 12 mm wide. Also cut four Velcro
straps approximately 12 mm wide by 180 mm long.
Using two 7mm wood screws per strap, attach two Velcro straps approximately 20 mm from
the end of each ply rail. Be sure to attach the straps so they overlap, holding the flat part of
the tank firmly against the ply rail.
The lower rail can be glued to the inside of the front former, but the upper rail should be
attached with screws accessed from the engine compartment such that the upper rail may be
removed. Strap the tank in place.
Photo 2 Photo 3
For extra security, place several pieces of scrap foam between the tank and the intakes, and
also between the top of the tank and the top of the fuse to keep it from shifting during flight.
To mount the saddle tanks, begin by routing two narrow 12 mm slots toward the outside of
the engine mounting rails. These should be positioned approximately 60 mm inside the front
and rear formers.
Cut two Velcro straps 350 mm long and thread them through the slots. Position the saddle
tank with the curvature to the outside and the stopper assembly at the front, and tighten the
straps. The tank should be canted slightly inward to allow the fuel lines to clear the inside of
