Not read the thread but prop tips check for cracks running from the tip
use a magnifying glass=2Ctape each prop tip the same amount oI could not se
e the tip cracks till it became a problem. Undercarriage leg covers check a
nd wind with
electrical tape also check any resin covers like flaps of fairings cowlin
g and bits check for vibration I have a sailing yacht and the long runs
of rope hum under tension and wind cowls can resonate hope it helps
but record the noise to us somebody knows the noise x x x > Subject: Eu
ropa-List: Re: Mysterious vibration on Europa Tri Gear
> From: gcgrant@supanet.com
> Date: Tue=2C 2 Aug 2011 10:30:42 -0700
> To: europa-list@matronics.com
>
>
> Ron=2C
>
> 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=2C bu
t I will explain why later.
> The carb bowl vents appear to be Ok and plumbed in and connected correctl
y.
> Switching mags makes no difference to the noise.
> The blades have been checked=2C 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.
> I can find no damage to the engine mount=2C or mounting bolts which are t
orqued correctly. The aircraft was converted to a Tri Gear in 2007
=93 which mod are you referring to?
> The chokes are closing correctly=2C there is no leak in the balancing tub
e and the plugs were replaced last September.
> The spinner is in good condition and on tight=2C with all screws checked
and hub appears to be fine. No changes have been made to any part of the pr
op system.
> I do not often use 100LL =93 only 40 litres in 33 hours. The total
engine time is 265 hours and as far as I know the gearbox has never been re
moved or checked. I have checked the slipper clutch friction torque and it
was 24 ft lb =93 well within the range stated by Rotax. I never have
any starting problems.
> When I was checking the slipper clutch I removed the four upper spark plu
gs. I was surprised to find those from cyls 2 and 4 were very black and soo
ty but 1 and 3 were perfect. I checked the needle jet in the left carburett
or and found the circlip located on the richest setting. I moved this down
one notch=2C re-assembled the carburettor and test flew the aircraft. For n
early one hour it was perfect with no vibration at any cruise setting from
28 inches to 25 inches MFP=2C but after descending into the circuit and ret
urning to cruise power the vibration/harmonic was very noticeable at 26 inc
hes MFP. Obviously I need to re-balance the carbs and I will do this tomor
row=2C 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.
> Regards
>
> --------
> Gordon Grant
>
> G-BWFH
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=348399#348399
>
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>
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