Hi! Gordon .
Have you checked your magnetic plug for ferrous swarf debris? I recommend
you to do this as if it were mandatory( I believe it to be at every 100
hours ) but I recommend it checked every oil change..
I have good reason to believe it is possible the anti -chatter drive dogs
are exhibiting back lash chatter. Propeller wind milling effect will allow
the lower RPM/drive torque position to be reached earlier and so allow the
drive dog/cams to be working together on a minimum bearing area of male
nose and female trough. It may well be that you need the propeller backlash
tightening up with shims .(This is not referring to the crankshaft
protection slipper clutch mounted between the propeller and the back lash
device. Whilst I'm not purporting to be an expert I have god reason to pass
this advice.
Do the check and also measure the prop. Torque "break out" load at 24 "
radius to see if it is in spec. If you are sure your carbs are
sinchronised/balanced first then this is the way to go for peace of mind.
I'm thinking I have the same "tee" shirt. Please let us know your outcome.
And what engine you have.?
Regards
Bob Harrison G-PTAG
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of GBWFH2010
Sent: 04 August 2011 13:14
Subject: Europa-List: Re: Mysterious vibration on Europa Tri Gear
Yesterday I balanced the carbs and test flew the aircraft. It was
beautifully smooth in the climb and cruise. I could initiate the noise by
reducing the throttle setting to below 25inches MFP, but everything returned
to normal at cruise power. Until I descended to join the circuit, when the
noise became apparent at cruise setting after descending to the circuit
height of 1000 ft. It was not as bad as previously as I could smooth it out
by slightly increasing power and it disappeared when selecting Climb pitch
on the downwind leg. Overall a great improvement.
I was very interested in Mike Toft's experience which seem very similar to
mine and although I have not ruled anything out everything seems to be
pointing to carburation. I think I will do the same as Mike and see what
happens.
--------
Gordon Grant
G-BWFH
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