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grumpyvette
02-23-2010, 07:08 AM
EXAMPLE

ok, first impression,
http://i47.tinypic.com/spdxme.jpg
http://i47.tinypic.com/2n6erg2.jpg

if you measure the plug gaps ID bet they measure greater than .045 thousands, ..they appear to be significantly larger and that takes a good deal more voltage to jump.
next,
look at the ground electrode, it appears to have its heat band go back to just short of the curved section indicating a retarding ignition or a overly rich fuel/air ratio
next
look at the insulation porcelain, and center electrodes, again both indicate low heat , usually the result of retarded ignition timing or a rich fuel air mix

reading these links and sub links should help

http://www.4secondsflat.com/Spark_plug_reading.html

http://forum.grumpysperformance.com/viewtopic.php?f=70&t=202

http://forum.grumpysperformance.com/viewtopic.php?f=4&t=1337&p=2921&hilit=+infrared#p2921

http://forum.grumpysperformance.com/viewtopic.php?f=55&t=109&p=6685&hilit=+fuel+air+ratio#p6685

http://forum.grumpysperformance.com/viewtopic.php?f=50&t=1853&p=4848&hilit=ratio+meter+fuel%2Fair#p4848

http://forum.grumpysperformance.com/viewtopic.php?f=70&t=1809&p=4671&hilit=+ignition+curve+advance#p4671
http://store.royalenfieldusa.com/media/catalog/product/cache/2/image/5e06319eda06f020e43594a9c230972d/z/9/z90708.jpg
http://www.aircraftspruce.com/catalog/graphics/12-21375.jpg
common but not very accurate
http://www.reluctantmechanic.com/images/spark-plug-gap-025.jpg
slightly more accurate

http://www.mytoolstore.com/kd/2327.gif

http://www.sears.com/shc/s/p_10153_12605_00994133000P

good accuracy at a low price
http://ep.yimg.com/ca/I/stylespilotshop_2090_220344251
thread chaser

http://ep.yimg.com/ca/I/stylespilotshop_2090_498933252
inspection tool

http://www.verrill.com/moto/sellingguide/sparkplugs/plugcolorchart.htm

http://www.4secondsflat.com/plug_chart.html

http://www.harborfreight.com/cpi/photos/94300-94399/94367.gif
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94367
dirt cheap plug inspection tool

http://forum.grumpysperformance.com/viewtopic.php?f=70&t=202

Donna_and_John
02-23-2010, 07:42 AM
Good info Grump :)

I use a "cheap" inspection tool that I got at a yard sale for $0.50 for looking a plugs. I also use feeler guages (the second example you showed) and small needle-nose pliers to gap my plugs. So far, this system has worked very well for me.

Another thing I learned many years ago was to always check the gap on brand new plugs. If you accidently drop one, even a short distance, always double check the gap. I do this even if the plug was still in its cardboard box. It doesn't take much force at all to alter the gap on a plug.