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Olaf , the squish area is where the piston comes closest to the head in the combustion chamber .

Summit racing sells a indexing kit for $54.00 #CSI-500

Jack

Has anybody on this site ever seen the "engine guru"
that has the little flash light with the magnifying glass
on the end of it looking at a plug????????? Does anybody
know what or where he is looking to "READ" a spark plug???
If anybody know that I'll be very surprised.
IT aint the white tip of the porsalon (sp) or the ring at the
bottom of the threads. Come on somebody tell me.

Paul H

PS I'll answer later.

Technically you should be looking down into the the plug at the insulator . The insulator should look as new with a brown fuel ring at the bottom of the insulator , the center electrodes should look like new with sharp corners and no blueing . I like to see base ring of the plug and the surface of the ground electrode a nice straw color . Remember I'm a Harley tuner not V8 expert .

Jack

Paul,
now you said something what really made me curious. There seems to be so much more to see on a spark plug than our fathers told us. I am surprised how much a spark plug can tell if in professional hands. I found a site with lots of info on this subject and have read it. Ok, I didn't understand everything, I have to read it at least one more time. But you are right on.

It's really interesting what is said to correctly read a spark plug - that's high end kind of stuff: (also the "external link" sources at the bottom of the page are more than interesting!)

http://en.wikibooks.org/wiki/Automobile ... park_plugs

Always willing to learn - so thanks for what you said. It's amazing what and especially WHERE the race pro's read a spark plug....cool stuff!!
Olaf

Jack D I should have known someone that's been
around like you would know what and where to look.

The flat area at the bottom of the thread won't tell
you anything. Unless it's black, that being to rich.
Brown on this area means nothing. If you engine
ever gets flooded what color smoke comes out of
the ex pipe. ??? BLACK. I've never seen brown
smoke so why use brown as an indecater to tune by.
At least not out by the threads or the white tip of
the plug.
The brown you see is fuel adatives burning off.

Do you pull the plug to check it after you've idealed
up the driveway ???? Yes if you want to know how it's
running in the driveway. If you want to know how it's
running at highway speed you have to do a clean shut
down at that speed. Kill the engine and find Neutuel .
Then full the plugs and maybe put an old set in to get
home. Yes the reading of the plug changes that quick.
More to follow MAYBE.

Paul H

Paul,

I always appreciate your postings and love to learn from the more experienced guys, so there is no need to talk to Jack if in reality you mean me.

Ok, seems like I shot myself when I were saying way too fast "my plugs look perfect", which make me look like a stupid dumbass now...hahahaha....

After I have read all the spark plug stuff in the internet I think I have learned a lot.

Well, at least the readings of my air/fuel ratio gauge seems to be fine during all riding conditions, although still very little on the rich side at WOT. I could go leaner but don't want to take the risk.

Allow me to correct myself - I don't know if the plugs look perfect, but I'm glad they look so much better now. After my lesson, I now know that the brown deposits of the fuel additives might not mean anything, but even they were unseeable before cause they were covered all over with the black powder of running way too rich. Now at least I can see something, brown deposits of fuel additives or whatever - that makes me happy, cause before I saw nothing than deep black.

I will leave them installed for a while...and then see how they compare to the pics in the internet.

Olaf

hogv8 wrote:Olaf , the squish area is where the piston comes closest to the head in the combustion chamber .

Summit racing sells a indexing kit for $54.00 #CSI-500

Jack

Jack,
thanks for posting the part number, but I think that's more than I hoped a set of indexing shims would cost. $20 would have been ok, but $54 sounds very expensive.

Now, after all that (new for me) stuff about the correct way of reading spark plugs, I wonder why we didn't had that important topic long before during all the years. That's good info you and Paul offered here.

Thanks,
Olaf

Thanks Elvis! Interresting info!