Finally got an OS F plug and gave it a try.

Pump is about 1 1/2 turns in from flush. High needle is now at about 1 3/8 turns open turning a 16.5x12W at 8600 with an acceptable idle around 2200.

Temp is 66, 45% humidity at 1100' elev.

It seems whatever you do with the pump your ownly adjusting the high end to match it. The engines seemed quite happy at about any setting of the high end needle in the air, even when it was over 2 turns with the leaner pump setting.

Robert