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From: "ctsmallwood"
Subject: Europa-List: Fuel smell 912S XS front fire wall
Hi All Occasional slight SMELL of fuel. ALL connections fully checked. On both
sides of fire wall(with developer).Fire Wall sealed prior to engine fit, and
again after engine/ flights.All Ally fittings aft. firewall Only place I
believe
it may be originating from is the Air Box. 2 small holes under each connection
to the Carbs(in Airbox). and entering cockpit thro throttle and brake slots
via tunnel Any help greatly appreciated Regards Colin Smallwood
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Hi Colin,
These comments are really directed at others who may have this problem since I
believe that you may have already used a leak detector (developer?). I
installed the factory supplied fuel hose as per the standard kit instructions.
After the first 100 hours I had an annoying intermittent fuel smell. I
carefully inspected and checked all connections without finding anything. The
problem seemed to get worse and I was still unable to find anything. I then
procured some fluorescent leak detector additive. (Mine was Dye-Lite, see
http://www.tracerline.com/ )
Anyway, before I had chance to try the detector, the leak developed into a drip.
At the main tank outlet, the hose had a crack under the hose clamp. I replaced
the length of hose.
My conclusions were :-
If I had to do it again, I would use aluminium tubing with AN flare fittings for
all fuselage fuel lines as I believe you have done. Ahead of the firewall, I
would probably use braided hose with swaged-on threaded hose fittings.
The factory supplied fuel hose with my kit has fabric braid on the outside only.
If there is a small leak, the fuel slowly wicks into the braid, evaporates and
is invisible. I believe that braid reinforcement in the wall of the hose is
much more preferable and will minimise hose cracking. If you choose to use a
fluorescent leak detector dye, it is important to get a good quality UV lamp or
you will have inadequate illumination.
Finally regarding the airbox, I notice that there is quite heavy staining inside
my airbox stub tubes from 100LL fuel dye. I usually fill with 100LL so I assume
there is quite a lot of neat fuel in there at some time. Am not sure how that
happens. An option for you might be to put small drain tubes onto these drain
holes and lead them to behind the wheel well.
Cheers, John
N262WF, mono XS, 912S, 430 hrs
Mooresville, North Carolina
704-664-4167
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