Bruce, I'm leaning more to the not fully broken in position more than anything else. The plug should be fine, and stay at that oil mix.

I don't know if the engine is on the plane or on a stand. If it's in the plane, remove the cowl and get her started. As long as the plane is positively secured, get a slotted screwdriver about 3/4 of an inch long. I like to use one of the short tips that come with a set that fits into a handle and shaft separately.

Now VERY carefully, with the engine running about 2500 to 3000 rpm, adjust the low end needle until the engine reaches peak rpm and then starts to fall off. Back up to the peak setting and either leave it there, or richen it up the width of the screwdriver blade. Whichever you feel most comfortable with.

Now, and again very carefully with the engine running at max rpm, adjust the high end needle to max rpm with a tach, then richen it up about 200 rpm. That should be pretty close.

That's how I do mine and it has worked without causing problems. If anyone has a better way, they should feel free to give it up.

Pat