Edited Date/Time
9/7/2026 5:10pm
Hey guys,
Have you ever seen a spark plug like this? YZ 250 2 stroke, it is jetted to perfection (piston, head, cylinder everything is looking brand new), running a mix of 110 avgas and 95 pump gas. Could it be the lead in the avgas causing this strange look? It is kind of a soot, and below it you can see the typical dark brown/black of a two stroke plug.
Yup, that's the lead from the AvGas. I get the same with the VP110 I blend with.
You’re ok, I’ve had this before with avgas.
I had the same thing, my father (who is a racer by nature - not a nuclear scientist) said, that it comes from different oxydations levels in the gas used. If you mix the pump gas and aviation fuel toghether, those O2 molecules are not broken, so they start burning a bit differently. Try using an E3 sparkplug, i had some truly beautiful plugs with those E3 sparkplug's
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