I changed out my spark plugs today. Discover plug #1 was soaked in oil on the thread side. The boot and hole was dry before removal of the plug. So I am thinking this couldn't be the gasket.

There was oil in the cavity where the 10mm bolt sits in between plug 1 and plug 2. I believe oil was spilled when refilling the engine at one point. Perhaps the oil made down through there? But the plug boot side was dry..

 

Valve cover gasket most likely. Maybe clean er up and check again in a few thousand miles.

 

The plugs pulled were made by Champion. A bit odd since they were replaced by dealer via warranty.

Anyhow that oiled plug had a gap of 1.3mm, quite wide compared to my replacement ngk plat of .85 and the used ones with 1.1-1.2mm

I put in a dry used plug into hole#1 and took a 10 min ride, let it cool and took the plug out. Plug tip had no oil, the threads had oil, the well had no oil, the boot had no oil.... I'd that not enough to test out the gasket?

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I bet it was just residual oil. I would give it some time and check again later. Since the boot and well were clean, your theory about just being spilled oil seems correct.