I haven't found the new service bulletin that I've heard is on the ram air
kit, but I unpacked my ram air kit today and checked the butterfly
screws. Not only were they not locktighted, they were only hand
tight. I also wonder about the bottom brass bushing. It is held in
place by being pressed into the aluminum ram air tube, but I was able to pry it
out using my fingernails. How long before it vibrates loose and falls away
leaving the butterfly shaft to rattle around in an over sized hole? Now
that I've taken the whole thing apart, I'm going to replace the butterfly shaft
with a bolt flattened and tapped to hold the flapper and the threaded end coming
out the top to hold the lever and a nut to hold it all in place. I'm also
going to remount the valve down towards the inlet opening where it is visible
and accessible.
----- Original Message -----
Sent: Wednesday, August 29, 2007 7:41
AM
Subject: Re:More Loose Screws
I could not
see any visible damage to the exhuast valve on my #5 when it ate a screw
but when tested by the cylinder shop the exhuast valve was leaking due
to damage from the screw exiting. Even if the valve was fine the shop ground
off all the burrs and high points caused by the screw to prevent them from
becoming a source of heat that causes the mixture to ignite early. Preignition
will quickly ruin your day and the engine.
Maybe I missed it. Did your friend pull #2 cyl and have it
checked and cleaned up? I not an A&P, but I would recommend it. I did the
R&R myself for the cost of a few gaskets. The local shop charges a flat
$300 for the job. That, plus the cost of any cylinder work is cheap insurance,
in my humble opinion.
Paul:
As far as I know, they
did a compression check on all the cyl's and they were all (including #2)
above 76/80. I'm not an expert on this at all, but wouldn't that
indicate an intact valve seat(s)?
Thanks for you help in originally
bringing this to our attention.
Erik
Larson
Legacy
N74FX