Spark Plug Reading was: WPSLPGExhaust Gas Oxygen (EGO) sensor Information

[Neil.Poersch at mts.mb.ca]

Grumpy,

Thanks for the info, every bit helps.  I agree with you in that adjusting
one variable can easily affect a different parameter than what one expects
it to.

I find setting WOT mixture the easiest of all.   I do a high speed plug
chop,  chuck the plugs in the lathe and cut off the outer shell.  You can
then see exactly where the soot ring is on the porcelain.  No guessing
involved at all.

The detonation thing I find a lot more difficult.  As you say it is an art
which you learn with experience.  After a three thousand mile trip to the
Rockies I noticed ( with an 8X magnifier) that my plugs had shiny metal
balls on one side of the side electrode.  The center electrode was
considerably rounded on the edges.  The center electrode had fuel salts on
it up to about 1/2 mm from the tip ( about the start of the electrode
rounding).  The porcelain had a generally light brown tint with little
brown specks or balls on it.  This was done with "normal" ignition advance
and mixture and 87 octane gas.

This weekend if I have some time I plan to do  some plug chops to check it
out some more.

Neil

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