Mailing List lml@lancaironline.net Message #32464
From: Dan Schaefer <dfs155@adelphia.net>
Sender: <marv@lancaironline.net>
Subject: Effects of Advanced Ignition Timing on TSIO-550-E3B
Date: Thu, 20 Oct 2005 16:13:40 -0400
To: <lml@lancaironline.net>
Allan Saul wrote:

"........after 50 tacho hours of engine operation and discovered that the
magneto
timing on both slicks was 28 degrees instead of the required 24 degrees
per the service manual and data plate. I have not touched the mags since
the engine was shipped from TCM."

After installing a new pair of Slicks on my O-235 a couple of years ago and
carefully setting the timing to spec with my buzz-box, I found after about
18 - 20 hours that they both had shifted approximately 3 degrees advanced -
one a little bit more than the other. After resetting them they have
remained almost exactly as set for nearly 200 hours.

I'm guessing that some small bit of initial wear somewhere in the mags
accounts for this - but it's only a guess. Don't know if this is typical of
all new Slicks but if you have (or install) new ones timing should probably
be checked within the first few hours.

On the other hand, personal experience says that just because that's the way
your engine was delivered probably doesn't mean a thing. After having my
engine factory overhauled (zero timed, new log book) following the Chevron
fuel debacle in California some years ago, I wouldn't even start an engine
that came from the factory (L or C) without a thorough careful check by your
local wrench. When mine was returned, without going into the dirty details,
I can confidently say it's only use, as delivered, was as an expensive boat
anchor.

Dan Schaefer


Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster