Hey guys .......just ran the first 2 tanks through the SPE 40. I tuned the needles a little and she runs great..............low idle and a vary fast transition to wide open throttle. My question......while I removed the plug to put my cowl on I inspected the plug(just for fun) usually I don't unless she not running right.........what I found was a little strange half of the plugs ceramic was light tan.....looked good, but the other half of the ceramic black , almost a perfect line between the 2.

What do you plug readers think?.................appears to be late timing and the flame front dying out before complete burn ...but this is only my second gas airplane so what the heck do I know. The engine runs great, plenty of power, smooth mid range, smooth WOT, and a vary good idle. Should I would fiddle with it or run a Gal or 2 first.