>> the simple test of running the output of the electric pump through a
clear tube should be
carried out. This shows up such a leak as a fine stream of bubbles. The
use
of two fully sealed types (which have bigger area anyway) gives immunity
against an air leak or clogging.<<
As I understand it, the presence of even small amounts of air in the flow
prevents both the electric AND the mechanical pump from drawing in
sufficient fuel to feed the engine. One might think the elctric pump would
make up for the deficiency by pumping harder but it doesn't because its
finite displacement is substantially occupied by expanding gas.
On the subject of filters, I think that a 70 micron fuel screen is better
than a 7 micron filter because it won't block as easily and the carburettor
will easily swallow anything up to 70 mu. We have already had filters block
in the Europa fleet.
Graham , glad you verified the problem Graham.
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