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Discussion Starter #1
This plug is out of a 95 gsr I rebuilt. The fuel pressure is set at 42 psi at idle. The plugs are rich but what im worried about is the white on the tip. I am running an 11.5:1 compression ratio. The plug is an ngk BKR7E. Should I be worried about how my plugs look? They look too white to me. Thanks for your input

Picture of the spark plug:
 

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I can't really tell from the picture because it is not close enough.. but it looks as if you may have a little pre-detonation. What octane fuel are you using?
 

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Super Bacon Mod
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hard to tell from the pic. But if it looks white thats pre-ignition. What octane are you running. At 11.5:1 91 cali octane is really really pushing the limits. if you are forced to run that low of octane, retard the ignition timing more.
 

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Discussion Starter #4
i run 93 all the time, i live in South dakota so its no problem to get
 

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I'm no expert, but I believe that white discolouration means your air/fuel is running too lean (not enough fuel). Please, correct me if I am wrong.
 

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mls said:
I'm no expert, but I believe that white discolouration means your air/fuel is running too lean (not enough fuel). Please, correct me if I am wrong.
No.. your right...that is lean...if he has any aluminum particals on the plug..then he has detonation...or if only the 'tip' is white.
 

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Super Bacon Mod
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deepstaged said:
No.. your right...that is lean...if he has any aluminum particals on the plug..then he has detonation...or if only the 'tip' is white.
The tip may not always be white. The grounding strap could be the only part that is white. That is a sign of pre-ignition as well, but not as severe. It can also be a sign of incresed cylinder temps as well though, but that is usually associated with pre-ignition. But you are right with the aluminum particles. That can be a very good sign of trouble, but that, by what I have seen, is a sign that its pretty much too late to do anything and you have internal damage although it may be repairable.

Now spark plugs are supposed to have a very light hint of white with a light brown. That is what a plug would/should look like under normal conditions and under a good air/fuel ratio. If the plug is a darker color then its too rich and too white is too lean.
 

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plug

ya just take it somewhere and get them to check the timing. if you are runing that high, you might want to advance 3 degrees or so.
 

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Super Bacon Mod
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God dont advance the timing any...you are already getting signs of pre-ignition....advancing it could make it even worse. too much advance causes detonation..however..too much retard can to..The best thing to do would be to get out a timing light and check your timing then go from there.
 

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Discussion Starter #10
well there are no signs of aluminum particles, it is possible to have a rich condition and preignition isnt it? i really dont think i am running lean, the rest of the plug is full of carbon, i wish i had a digi cam i had to get that image i posted off a scanner thats why it sucks. I have a timing light and checked it out but it is a motor swap and when i got it the crank pulley was chipped exactly where the timing mark is , i am going to replace it next but i gotta get some money. I pulled the timing back to be safer for now (and its not being driven anyway, put away for the winter), but when i did the research and built the motor with the 11.5:1 pistons i was told i would be just fine on 93 with that c/r? is that not true?
 

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Super Bacon Mod
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yes..you can be over rich and detonate...but it is not as easy to do...my bet is jsut too muc ignition advance and that is where the white is comeing from....I mean..some white is ok..but by the pics..it looks like there is more then there should be...yes..11.5:1 octane should run fine on 93..there are guys running out in cali on 91 at that ratio and are doing alright...they are pushing it..but still...just retard the timing a little..and see how that works...remember..intake air tempature also plays a big part in detonation too...but..because its november..you shouldnt have this problem...but im still pretty sure its most likely that your ignition timing is advanced maybe a couple degrees too much...if you arnt hearing any pinging or knocking i'd just retard your timing 1 or 2 degrees and see what that does for you..
 

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Now that you guys mentioned it, I remember reading an article about spark plug leads. They chopped a lead open to show you what happens when the spark energy (electrical current) does not fully reach the plug electrode & arcs (or whatever they call it). & you guessed it, there was white discolouration inside the spark plug lead.

Also, if you are detonating, then the last thing you want to do it advance your timing, as said by VTECsqznN2O. To minimize the chance of detonation, retard the timing, but this can cause a loss of power.
 
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