What's Going on Here?

When the engine warms up and sits during plug cleaning the engine heat
drys out the water in the magneto and/or the plug wire. Result is the
problem is gone. I would test the spark plug with a pressure test to
make sure it is not internally cracked and will fire under pressure
and I would also high voltage test the plug wire or just replace that
wire. Also inspect the distrubitor in the mag for carbon tracks.

Thanks, John. My A&P and I are going to check all that out
tomorrow.

Incidentally, I've noticed a wide variation in pricing on new spark
plug wiring, ranging from ~$170 to $300. This is a HUGE variation,
for something so mundane -- can anyone comment on why this is?

My A&P is partial to the Unison ("Slick") brand, which is over $300.
He says they are more expensive because each piece can be easily
individually replaced, whereas the cheaper brands just "crimp"
everything together, making them harder to repair.

Can anyone recommend (or steer me away from) a brand?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

On Apr 4, 6:37 pm, "Jay Honeck" wrote:

Can anyone recommend (or steer me away from) a brand?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993www.AlexisParkInn.com
"Your Aviation Destination"

Jay,

Mike Busch and lots of members of the Cessna Pilots Assoc. recommend
the Unison/Slick harnesses whether you have Slick mags or Bendix. They
say the wires on the Slick harnesses are more flexible and the
"cigarettes" are better as well. I have no experience either way, just
thought I'd pass along what I've read on the CPA forums.


Brock Boss
3916R - KAAA

I think it still could be a bad plug- my understanding is that they can look
good while still being weak under a load- did you check it in one of those
fancy spark plug testers?

It seems to me a simple test would be to swap two plugs- it the problem
remained with the "new" plug, then the problem likely would lie in the
harness.

Can anyone recommend (or steer me away from) a brand?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993www.AlexisParkInn.com
"Your Aviation Destination"

Well, Slick's are slick but the devil is in the details.. When Fat
Albert needed the mags spiffed up I elected to replace them totally
over just replacing parts... I looked at the Slicks and really like
them... But, a grizzled and really old A&P, name of Bill, looked at
me, rolled his cigarette from one side of his mouth to the other and
said, "Check and see if anyone can fix a Slick magneto, right today.
Tell em you gotta fly home tonight" (This was 10AM on December
24th)... Then he gave me that evil grin he is known for...
So I whipped out my trusty cellphone and called three different FBO's
in Michigan... Nobody had parts for a Slick but they all had most
parts for Bendix and one even said he had the adapter for the Slick
harness and could put a Bendix magneto together for me that would work
and get me home..
I bought 4 rebuilt Bendix mags... The Fat Boy starts like he is a
teenager again... And I know that if they break down almost any FBO
will have parts on hand...

denny

On Apr 4, 6:17 pm, "Viperdoc" wrote:
I think it still could be a bad plug- my understanding is that they can look
good while still being weak under a load- did you check it in one of those
fancy spark plug testers?

It seems to me a simple test would be to swap two plugs- it the problem
remained with the "new" plug, then the problem likely would lie in the
harness.

We'll check that later today, but it seems unlikely that it's the
plug, since it's been replaced in between occurences, and it *still*
happened on the same cylinder, same plug position.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Well, Slick's are slick but the devil is in the details..

Thanks, Denny -- but I'm only replacing the spark plug wiring harness
at this point.

I hope!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Well, Slick's are slick but the devil is in the details..

The fix is in: Atlas does have a Slick harness, and my A&P has all the
pieces/parts to craft a new spark plug wire for our #2 cylinder, from
the right mag.

This will save me approximately $250, and should fix the problem. He
said he'll have it done before we leave for SNF.

He inspected the harness, and could find no reason to replace the
entire thing, as there were only normal signs of age.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"