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Plug Chop Pics

bigred455

"LET'S JUST RIDE"
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Sep 12, 2000
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#1
I know the majority of you have seen plug pics and know with a new plug looking at the tip of the insulator is useless,so read over what you already know .


If anyone has read Gordon jennings article on spark plugs it is a very good read.He mentions checking the mixture ring down at the base of the insulator for checking your main jet . I see a lot of riders telling other riders that if the insulator on the spark plug is white you are running too lean.They do not bother to ask if it is a new plug or used plug.The reason I say new or used is,you will not color the insulator up by the tip if the plug is new it takes some time to color that area of the plug .You can be running 5 sizes too rich and you will still not get color. If you listen and feel your motor it will tell you everything you need to know,but you have to put in the time. I do not like to jet by the plug color, their are too many variables involved, different oil and fuel properties DIFFERENT COLOR READINGS. Gordon Jennings talks about the fuel mixture ring down at the base of the insulator and he is correct. I will prove his article is right on the money in the plug pictures I have taken on my 03 kx250. The only thing I did not agree with is how the ring is suppose to climb higher the richer you go. I found out that the richer you go the darker the ring becomes not higher. I warmed up the motor with my plug I use at normal riding conditions BR8EIX shut it down and put a brand new BR8ES the first run and a brand new BR8EG THE second run. As soon as the motor was running I went off and did 3 fast passes reached full throttle held for 5 sec and repeated with the new 2nd plug. I had my jetting all sorted out weeks before this test,like I said I like to jet by trial and error but hey I was curious. The pic on the left is with a 148 main this is what I chose just by listening and feeling the motor I got her right on the mark and the plug does reflect that. The plug on the right was run with a 152 just to see if the mixture ring did change. If you are jetting by the plug color you are wasting your time looking at the insulator tip. ENJOY!
Keith 455.
" LET'S JUST RIDE"

pictures
 
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steve125

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#3
A couple of things, I think it would have been best to have used the same plug for the comparasion. The ES plug looks to be on the border of lean, the EG plug looks real close for good power along with a safe jetting spec.

If you were to continue to test and richen the main jet,  the ring will darken and climb up the insulator.
 
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bigred455

"LET'S JUST RIDE"
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#4
Steve when I first cut them open and seen that the EG (152 MAIN) richer did not climb higher,but did darken,I was wondering if the different insulator played a role. If you look closely the ES( 148 main) leaner is a little higher,but lighter shade.You can clearly see the difference in ring color though.Forgetting about ring colors, I was done jetting a few weeks before I tested the plugs same temp. The 152 was too rich I was getting a slight miss up top, it wen't away with the 148.I tore apart my top end after 45 hrs and she was not running lean. The 148 definetly gave me the best power without going dangerously lean. I believe the color of the ring(148) is dead on, to my likings anyway.I really do not like to get hung up by ring color,but to kinda reconfirm after your done jetting is a fine tool. The only reason I do not like to jet by plug color is, let's say if it was a perfect world and I changed to a different oil and fuel and the same jetting was correct for this . I bet the color of the ring would be a different shade than the fuel and oil I am using, maybe darker maybe lighter.You know different oils and different fuels give off their own distinct color I changed oils too many times and seen this, the tip of the insulator is totally colored different. Basically I am just getting tired of riders telling other riders that they are running too lean ,because the insulator tip is white,and do not bother to ask if it is a new plug.
 
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bigred455

"LET'S JUST RIDE"
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#5
Originally posted by georgieboy
Very nice Keith, thx for the pics. It really helps visualising. ciao george
........

George thank you for the kind words!