Black spots on Spark plugs

[b58.brady1]

Since replacing my spark plugs, i’ve gotten a sputter on my startup every once in a while so I decided to pull my spark plugs and check, they had this black spot on them. Anyone know what it could be? Around 1000 miles on them

[allinon72]

Mine had similar spots, I don't think it's abnormal. Harder to see on mine because they are dirtier, but notice the light and dark sides.

[ApexEight]

Which plugs? Tuned? Coil packs weren't changed?

[b58.brady1]

Originally Posted by ApexEight

Which plugs? Tuned? Coil packs weren't changed?

Coil packs were changed, i went stage 1 after i changed them. NGK-96206 plugs

[Tejas1836]

Where did you buy your spark plugs?

[b58.brady1]

Originally Posted by Tejas1836

Where did you buy your spark plugs?

I bought the kit from fcp euro