Routing of the fuel line through the Europa Mk1's tunnel is not specified in
the manual. One must avoid conflict with the landing gear so must install the
gear to decide where to place the line. But, once the gear is in place it's
much more difficult to reach the places where the Ty-wrap pads are needed.
While the routing described here is not the only possibility for a Rotax
installation, it seems to avoid conflicts within the tunnel.
The Ty-wrap pads used to secure the fuel lines have double sided foam for
mounting. This foam must be removed and the pads floxed in place to ensure
their security at high temperatures and after exposure to fuel. It is far
easier and leads to a neater job if these pads are installed prior to
installing the LG.
The center of my middle pad is located 1.75 inches below the rear mounting
bolt for the brake master cylinder. This is low enough to clear the brake
line and high enough to avoid the tire. This is the most likely place for
conflict since it is at the approximate wheel center.
Another pad is located mid way between this pad and the holes in the tunnel
bulkhead where the fuel lines enter.
A third pad is located 7.5 inches forward of the center pad and 4 inches down
---From the top of the tunnel. This locates the upper fuel supply line about
1/2
inch below the flap drive rod in the gear-extended position (this rod rises
when the gear is retracted).
The upper fuel supply line and the lower fuel return line are routed along
these pads and then through the center of the LG frame where they are secured
to the stbd side strut and down against the large diameter cross tube. This
is a fairly straight run from the pads, curving inboard to clear the flap
drive.
A detail about the fuel return line: a J0604 reducer is desirable aft of the
tunnel bulkhead rather than stretching the hose to fit, which is near
impossible with the stainless mesh.
The starboard side stainless firewall needs two holes, one .75 inch below the
top edge, the second 1.75 inches below the top edge. These are located such
that the edge of the resulting hole is 1/8 inch from the inboard edge of the
stbd section, allowing the fuel lines to pass inboard of the LG member. The
bottom hole is 5/8 inch to allow a plastic grommet around the return line; The
upper hole is slightly larger to accommodate the slightly larger supply line
and grommet.
The center section of the firewall needs slots cut to accommodate these
grommets added to the stbd section while allowing removal of the center
section.
The fuel lines pass upward from the LG cross tube and pass through these holes
in the stbd section of the firewall; they are secured to the strut supporting
the LG cross tube just prior to passing through the firewall. For those using
hose fittings to pass through the firewall (instead of grommets), consider a
45 degree angled fitting to simplify routing.
For the etc. part, I located the choke on the side of the throttle box so
that it is between the throttle and the LG lever, similar to Kim Prout's. The
throttle box was extended to the side and a cylindrical piece of foam cut at
an angle so that the choke emerges at 30 degrees upward from the center
console was placed so that the top front edge is 1 inch forward of the forward
throttle mounting bolt and centered 1 3/8 inch to port of this bolt. This
foam was angled slightly so that the cables would angle to the stbd side when
the throttle box was mounted, this to ease routing of the choke cables. It
would be easiest to include the choke holder when making the throttle box
rather than adding it later as I did. It worked out nicely, fitting about
1/4 inch from the LG tufnol and allowing easy removal of both the choke and
the throttle with two screws. I opened a hole in the tunnel which includes
the complete choke holder, then realized that the forward inch isn't needed
and could be left in place... Putting the choke here simplifies instrument
panel removal since the choke need not be removed.
And finally, where the throttle and choke cables pass through the stbd side of
the firewall and over the top of the LG member which the bungee passes over.
Cut a 1/4 inch slit, 1 inch in from the stbd side of the center firewall
section. Bend the resulting flap down rather than cutting it off, to give a
smooth transition for the 4 cables as they pass through. Fill around the
cables with RTV as specified in the manual.
As usual, questions remain: what have others done with the ends of the
stainless mesh on the fuel lines. These ends are very sharp and slice ones
fingers without mercy. Would smearing with RTV help/be appropriate?
The devil is in the (mundane) details. Comments on the above would be
appreciated, especially if I've overlooked something.
John A044
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