Help reading spark plugs

hangn0ut said

A 3 is on the cold side for plugs. Especially for the street. I think just a hair rich but that might be the cold plug. Like to see a 5. Now what are you all looking at? I'am looking at the metal ring the ground strap is welded to. Looking for a dark grey,not black. Your close. Google "plug reading 101 by Mike Canter". This is to tune for power. Go leaner on the rods for cruising.

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I thought the 9yc was the stock heat range plug for a hi compression 340, so i was just figured that would be the logical choice.

So what I think you are saying is a "hotter" plug would have an effect on mixture. Or is it combustion/ flame propagation?

I was looking at his info (Mike Carter), I guess I will order a strip kit for the eddy, and see how she does. I was a little confused between the insulator and that outer band, I've always looked for that tan colored insulator in the past.

The grounding electrode seems to have a flame travel about 66% of it's length, so it seems to me to be pretty good.

I will see about getting some photos using a real camera instead of the phone camera.