1968 Spark Plug Discoloration

[Mosesatm]

Does anyone know what could cause the brown discoloration on the spark plug (#1) on the right of this photo? It looks like rust, which it may be, since the plugs are not new, but I'd think rust would burn off.

They go 1-8 from right to left. It looks to me like #5 is getting a little oil and the rears may be a little lean, but the brown tip of #1 has be perplexed.

 

[franklinair]

How many miles on these? How old are they?
I would recommend cleaning, re-install, and then hiway drive for about an hour and then re-examine.

Neil

 

[robert campbell]

Arlie,
I agree with Neil. They look almost brand new! Unless it is running bad or you made a major carb/cam change and are rejetting, I would drive them for a lot more.

Rob

 

[Mosesatm]

The plugs have less than 100 miles on them.

I pulled them to see whether the new carb is running rich or lean. All in all I'm happy with how they look except for the funky one. I'll clean it and/or replace it and see what happens.

Thanks for the advice.