[RVG8tor]

So I pulled my plugs and they all seem to look good, except number two and four. Number two had oily threads on the plug but not the adapter (auto plugs) yet the adapter did not have oil on the it's threads. The spark end of the plugs was a nice whitish color and did not seem to be fouled by oil. I wonder what this might indicate.

Number four has a reddish brown color to the ceramic bit under the electrode, it has a noticeable difference from the other plugs.

I took some pictures...

This first picture shows the oil on the threads but you can there is not residue on the spark end.

These next two shots show the number 4 plugs.

This last show shows number two plugs next to number 4 for comparison.

So how does one interpret this, I have not had any issues with the engine so far. I have been flying for a year and have 161 hours.

Cheers