Hi Kevin,
This has already been said to some extent - but here are my comments for
what they are worth.
I also have an XS with the 914. Andy Draper from the factory did the first 5
hours test flying and I have now done a further 20 hours.
On three occasions during the first 5 hours Andy experienced the engine
cutting suddenly and almost stopping. This happened when only one fuel pump
was on ie. during normal flight. It was cured, before the engine stopped in
each case, by switching on the second fuel pump.
Andy believed it might have been a faulty No 1 fuel pump that was cutting
out occasionally. But on each occasion the filters were found to have quite
visible dirt in them and, because switching the pumps over did not stop the
problem, my theory is that it was definitely partial blocking of the filter
which caused the problem. It occurred again after about 10 hours flying and
I switched on the second pump immediately and the engine picked up OK.
Again, there was considerable debris in the main fuel filter. Since then -
because the effect of the occurrence is bad news for the heart muscles - I
have inspected the filters every three hours and generally ended up changing
them because of visible dirt. It has not happened again.
I am certain that is is simply not possible to ensure that the fuel tank is
free of swarf, bits of rubber from the inlet pipe etc and these bits do get
into the filters for hours afterwards. There has been a lot of discussion in
the group about this and the majority seem to think that the filters would
be much better replaced by a gascolator, as made by Andair. Graham Singleton
seems particularly keen on this and can advise. I think I am going to change
mine because it simply is not sound practice to keep pulling the filters
apart the whole time just to try to avoid having a thoroughly unpleasant
experience!
Can you remember if you tried switching on the second fuel pump. I rather
imagine you might have been preoccupied finding somewhere to land! Poor
chap!
Mark
-----Original Message-----
From: owner-europa@aztec.houxou.com
Subject: Re: Europa filters
Recently I completed my XS with the 914 engine. It flew well but on the
third flight the engine failed and I force landed. Luckily there was not
too much damage to myself or the aircraft . Needless to say I am very
interested to understand why the motor stopped.[ I have left out the heart
stopping part in case there are Europa pilots out there with weak
constitutions]
There are two puralator filters on the 914 set-up and the first conclusion
is that both filters became blocked.
After recovering the aircraft I dissconnected the carby line and attached a
clear tube . Fuel flowed but one filter/pump combination was delivering a
line of bubbles.
A second possible conclusion is that the bubbles accumulate somewhere un the
line and form a vapour lock.
The filters were at least partially blocked with fine material . I had been
obsessive with cleanliness in construction /fuel purity etc and had cleaned
the filters after the first flight with little dirt visible.
I have spoken to three other builders [ two here in Australia ] who have had
bad experiences with engine starvation .Not every one has had a forced
landing but they are 'Spooked ' by this problem.
The common thread is the puralator filter .They seem to be too fine and to
have too small a surface area so that when even a little material comes
along they choke. Additionally the are prone to leak air [ possibly with the
greater fuel pressure or the 914 pumps this is a new factor].
The factory tell me I'm a wimp.'Clean the filters regularly and all will be
well' 'We have had hundreds of hours on the puralator filter'
The other common thread is that ,in general ,the problem occurs in the early
testing time leading people to assume that it's builders fibre glass thats
causing the problem.. Is it possible that some of the tanks have a residue
---From the original building???
When I inquire I find a good proportion of builders have already abandoned
the factory puralator filters.
Does everyone know something I should know??
This problem has the capacity to harm the Europa . I would be pleased to be
guided by the experience of others.
Could any one else who has had a starvation problem put that experience on
this forum so that the problem and its extent can be grappled with.
I would be very grateful for any help in this matter. Kevin Pownall
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