Hi Gordon
Reply below ****
<gcgrant@supanet.com>
>
> Ron,
>
> Thank you for your suggestions which are greatly appreciated. I have
been
> working on the Europa today checking a number of the things you
suggested.
>
> I found all cables to be in good condition and the physical
operation of
> the carbs appears to be correct and in sync. I have yet to re
balance, but
> I will explain why later.
> The carb bowl vents appear to be Ok and plumbed in and connected
> correctly.
> Switching mags makes no difference to the noise.
> The blades have been checked, are all at the same pitch and are
within the
> manufacturers limits. A basic check of the tracking has been
conducted and
> no problems highlighted. The blades have not been dynamically
balanced.
****Good idea to try and get rebalanced no matter.
> I can find no damage to the engine mount, or mounting bolts which
are
> torqued correctly. The aircraft was converted to a Tri Gear in 2007
€“
> which mod are you referring to?
****Mod 72:
http://www.europa-aircraft.com/updates/mods.php
****Below 5K the manifold does not provide equal mixing, think a very
common problem. If you were to run at 5K for a while and turn off you
would probably see nice color of plugs. i am not flying yet but do know
Type 64 carbs. Adjusting idle needle as lean as you can may help.
I checked the needle jet in the left
> carburettor and found the circlip located on the richest setting. I
moved
> this down one notch, re-assembled the carburettor and test flew
the
> aircraft. For nearly one hour it was perfect with no vibration at
any
> cruise setting from 28 inches to 25 inches MFP, but after descending
into
> the circuit and returning to cruise power the vibration/harmonic was
very
> noticeable at 26 inches MFP. Obviously I need to re-balance the
carbs and
> I will do this tomorrow, but it does seem that working on the
> carburettors/air intake system seems to improve things for up to 60
mins
> and then the problem returns.
****Be very careful messing with main jets and jet needle settings.
Verify and clean jets, my 914 has different main jets and different jet
needle positions I think from the factory.
Go after carbs. Even though the enriching circuit is not supposed to do
much in cruise, you can try pulling choke at cruise and see if that makes
a difference. Perhaps ask Bud or Airmaster if you can try and switching
blades?
Good luck
Ron P.
> Regards
>
> --------
> Gordon Grant
>
> G-BWFH
>
>
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>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=348399#348399
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