Plug chop pics

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Plug Chop Pics
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"

plug pictures
 
Nice pics!!! However, I would say you are "safely rich" and could still even go one jet size leaner -- you would gain some more full throttle mid rpm horsepower but loose some of the cooling effect on the top end. The timing ring on the left plug looks about 2 to 3 degrees too advanced and backing off the timing by that amount would probably gain back the horsepower missed at the top end by going leaner. Thus, overall more trackable power could be gained by one jet size leaner and 2 to 3 degrees less timing. Too little usage on the plugs to tell if you have the heat range correct. I see no signs of detonation. You should log ambient temp and humidity as well as altitude if you ride at different evevations and get down to some real serious fine tuning -- that is if you are looking for that last touch of competitive edge.
rolleyes.gif
 
Good pics! I always get a kick out of the guys that tune their high dollar motors by staring at the end of their sparkplugs. Might as well use a divining rod or chicken entrails to tune by.
I have found that with a 250 mx bike little is gained by going leaner than you are right now. If you do decide to tune it right to the edge get some good race fuel and use a RAD gauge. You still have to account for the differnt loads that certain tracks place on the motor though. Clearly a track like Southwick loads the motor muc more than one like Troy, OH.

[ January 15, 2004, 01:31 AM: Message edited by: blano ]
 
Thanks for the compliments and opinions of the pics. Keith 455.
"LET'S JUST RIDE"
 
Your right white is lean or to hot of plug, tan or light brown is perfect. When its black its too rich. I believe the black is carbon build up. Wet and black is the same but is caused by excessive ring blow-by. Nice pics
 
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