Diagnose Spark Plug - Something's Wrong

[vesnyder]

Attached is a plug I just removed from my rebuilt motor - about 600 miles - and my milage (MPG) is horrendous. Any ideas?

[stlrj]

Now you need to find out why it's running so rich. Things to check might begin with the frequency valve operational, 02 sensor, dome light working? Or take it to a wrench who's familiar with these hints.

[David]

Do all the plugs look the same?

[vesnyder]

I actually ran it on teh freeway then shut it down without taking it to idle and snapped th epic then - so I only checked one plug. Whan I changed the plugs about 200 miles ago they were all similar.

[Zeke]

That explains to me why the plug and black and white at the same time. Is the O2 sensor hooked up? I guess you ought be chasing idle mixtures because the freeway RPM is actually lean.

that didn't make any sense, did it?

[cgarr]

Get more miles than 600 on it. I assume this is you SC and not the 914?

[snbush67]

Maybe its the angle of the photo but that gap looks a little tight, are you getting higher then normal engine temps?