Hi Gordon,
We had a similar problem with my Trigear XS with 914 Rotax - and after many
hours
of carb stripping and cleaning and balancing with a mercury manometer - we
could not fix it till - we re-stripped the carbs and found a small defect on the
base of one of the float chamber needles that caused the needle to "cock" to
one side from time to time( we think) - we renewed needles and the float
actuator
arms - re- balanced the carbs and hey presto problem gone. The aircraft
had stood for a while prior to the problem.
Regards
Mike Toft
Europa XS Trigear 914 Airmaster
On 31 Jul 2011, at 9:07 PM, rparigoris wrote:
>
> Hi Gordon
>
> A few thoughts:
> **Although you stated that you have balanced the carbs, did you check that
> they
are being opened the same throughout the throttle range? Do you have a kinked
or otherwise compromised set of cables? Did you try balancing at around the
throttle position you are having a problem?
> **Are your carb float bowl vents in good condition and both plumbed to approx.
ambient pressure?
> **If you switch from both to left then right mag, is there a change?
> **I am not sure, did you check the tracking of the blades? Did you measure
> that
the blades are the same pitch, especially at the approx pitch where you are
having vibrations?
> **Did you ever dynamic balance the blades?
> **Did you do the mod to undercarriage mounting frame? Is it or the motor mount
cracked? Is the engine mounting bolts (Binx nuts) properly torqued? Are the
motor mounts in OK condition?
> **Is the choke (enriching circuit) cables completely closing the arms?
> **Is there a leak in the balancing tube?
> **When was the last time you replaced the spark plugs? Is there a chance you
may have wires that got mixed up?
> **Is the spinner tight with screws tight and no cracks and does it track true?
Is the backing plate cracked? Did you by chance install different hardware where
on the spinner, back plate or other is causing the prop to be out of balance?
> ** How many hours on your gearbox since it was checked? Do you have a slipper
clutch? Do you use 100LL a lot? do you have a problem starting?
>
> Have a look through here, especially vibration:
> http://www.europaowners.org/forums/gallery2.php?g2_itemId=81550
>
> Ron Parigoris
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=348176#348176
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