spark plug post-mortum

[carlo]

My car had a bit of a miss when up about 5000-7000rpm. I was due for a spark plug change so figured that was the cause.

Now yet to fire the car up again to see if the new plugs fixed the issue.. but thought I would ask for your opinions with this spark plug from Cyln 4.

See how one of them seems all oxidised..

any idea what would cause that.. it only happened to one and i have never seen it before.

[Damo]

http://www.ngk.com.au/spark_plug_analysis.htm

Check out the above sight. Might have been just a bit of moisture or not sealing properly.

[carlo]

Hrm.. yeah water must have been the cause..

[sewid]

How many K's have those done?

[T0nyGTSt]

Hmmm...

$16 iridiums too :-(

I had plain NGK BCPR6ES or BCPR7ES coppers and I cracked a whole bunch of the ceramic casings in less than 2,000km - no idea why; these are the same ones that everyone recommends.

I now use those murderously expensive Iriways and they seem ok after a few thousand.

T.

[benm]

I've got some BCPR6ES's going in tomorrow. I'll post some pics of my 50,000km old Iridiums tomorrow.

[2rismo]

Those plugs just look a bit coroded around the thread. Bit of moisture got in there mate. Make sure the new ones are seated properly when installed next time but not too tight of course.

The top and centre electrodes look fine though.

Adrian

[scuzzy]

Hey I got some of those new irridium plugs. On the box it states not to gap em as you can damage the fine electrodes. I went to a performace shop and they said to gap em at .85. They are 1.1 out of the box.

???

[Abo Bob]

Gap them to 0.8 but be extra gentle and careful.

[carlo]

I always buy pre-gapped plugs.

the ones that came out of the car where about 4 trackdays old.. Perhaps 20,000km maybe.