Reading Spark Plugs

[mack]

As most of you members know, I'm new to the mechanic field. So I read the thread where someone burnt a hole in his piston by running too lean. I went out and pulled my plugs realized I wouldn't know by looking at them what the motor was doing so I put them in my truck and took them to someone who would. I was absolutely amazed at the info that can be gathered from looking at the plugs. Idle , middle and holy crap settings/jetting, timing etc. Problem is the guy never explained how all this is done, what to look for or what he was looking at. I'd really like to learn this feat of magic. Any one have a technical source with lots of good pictures. I've been to the NGK and Champion sites and while the naratives are good, there is a clear lack of pictures showing exactly what they are talking about.

[FJ111200]

Scroll down the link to see the plugs and then click on the image to enlarge and see the text.

http://www.mye28.com/viewtopic.php?t=88052

[mack]

reading plugs

Ya that is similar to the NGK site. I was reading an article by Gordon Jennings last night and basically looking at the tip of the plug is a small portion of the story. True readings are taken deep down and timing is apparently read by looking at the ground bridge. But again no pictures.

[crazy steve]

Mack, plug reading is a bit of a black art...

The big problem I've seen is all the 'instructional' pics you see are probably 40 years old and based on leaded gas, and except for the extreme cases, you need a super-sharp eye to see the differences these days with unleaded fuel. Unleaded burns much cleaner and just doesn't leave the traces that leaded fuel did. It is possible to 'read' them, but it's not as obvious anymore...