Spark Plug Reading Question

[Hallett19]

I used to know what all the colors and all meant but I have had these plugs in for a while now, about a year if not more. Well, upon inspection, they are very very dark in color, and the porcelin part was very very red, like a mars red. What does it mean ? They were very similar, none of them looked darker or lighter than the other by any considerable amount. But a few of them the porcelin was more red than others and a few were just black. Thanks for any help.

[77charger]

do you run any additives.I know octane boosters give a red tint to the porcelin.As long as they aint white with speckels on them i;d say you are ok.

[Hallett19]

yeah, I run Marvel Mystery oil in the tanks and I just recently ran some octane booster to some 87 octane that I put in there. No sparkles though !! I know that means detonation, but the red and the dark black color concerned me.

[GofastRacer]

Marvel is a lubricant and won't show up on a plug reading(at least I've never seen it) but octane boosters will!. The worst one is got to be that 104 shit, it makes the plugs look like rust lean or rich!..:rolleyes:

[Rexone]

check the spark plug reading link in the top thread

[HalletDave]

Hallett19,
If your plugs are all black from idling for long periods of time, you can spray the tips with brake cleaner and the original burn pattern will still be there for you to read.
Caution: Do not let brake cleaner come in contact with painted surfaces.