Still fine tuning the tuning: [img]<<GRAEMLIN_URL>>/grin.gif[/img]
I bought a one step colder set of UR5GP NGK plugs to see how they burn. After 35 years of wrenching I'm still learning about stuff, like how to read the electrode and where the burn mark should be.
Here's the UR4GP, burning a bit too hot, as the flame mark on the electrode is closer to the base than it should be. (Too close to the tip would indicate too cold of a heat range).
And the UR5GP burning the preferred area, halfway up the electrode:
And here is the base ring color with a consistent brownish tone, allegedly indicating proper carb jetting/fuel mixture:
Any tuning gurus out there, feel free to chime in with your opinions!
This looked like an interesting article on plug reading:
http://www.wallaceracing.com/plug-reading-lm.html