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ACRO E-mail Archive Thread: [Acro] =?utf-8?B?UkU6IFtBY3JvXSBTcGFyayBQbHVnc ...


Thread: [Acro] =?utf-8?B?UkU6IFtBY3JvXSBTcGFyayBQbHVnc ...

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From: =?utf-8?B?U2VwcGFuZW4sIEthcmkgSg==?= <kari.j.seppanen at>

Date: Sat, 03 Aug 2002 00:00:53 UTC


  The best way to check whether the plugs are worn is to use the little
erosion guage Champion hands out at Oshkosh and Sun 'n Fun. The P/N is
CT-482 and they are for massive electrode plugs only. They're free at the
shows but I don't know if you can get them for that price at other times. If
your plug fits through the little hole after gapping, it's worn out.  

Kari J. Seppanen
Flight Test Engineering Analysis 
Aerodynamic Performance Group
kari.j.seppanen at
N909RC E33C

-----Original Message-----
From: Dave Walkup [mailto:dwalkup at]
Sent: Wednesday, July 31, 2002 7:54 AM
To: acro at
Subject: [Acro] Spark Plugs

Any opinions out there on which plugs to use on an AEIO-540 with 10-1
compression?  Our acro mount has been using a combo of fine wire and massive
core.  The massive core have always been installed on the top.  Recently,
one (or now two) of the fine wires on the bottom have become fouled after
3-4 short acro flights over a three hour period.  My mechanic thinks that
maybe we should switch to massive core for the bottom too.  The reasoning is
they hold heat better, that maybe pulling the throttle back during acro and
landing right after 15 minutes in the box, the fine wire cools rapidly and
contribute to the plug fouling.  Both mags have just been off and rebuilt,
so I don't suspect a problem there.  The engine does run VERY rich on the
ground, so leaning on taxi is a must.  The plug fouling cannot be corrected
by ground runup and leaning.  We pull them, put them on the bench, clean and
they fire again ok.  Maybe they just getting old?
Thanks for any advise you have,


© Dr. Günther Eichhorn
Email Guenther Eichhorn