Reminds me of tuning my old RC plane 2 stroke engines. Would have them suckers turning 14 to 16 K when properly tuned.
So when we would get the motor broke in and were ready to final tune it, we would hold the plane straight up in the air at WOT
and give the fuel line a quick pinch, if it coughed and almost died it was too lean, if it gave a quick rpm
burst then started to die it was dialed in real close. A VERY FINE LINE between rich and lean at that point so be careful if you try it, but knowing you and how you like everything being at peak performance, thought I would throw that out at you.