Bill Baxter at Futaba pointed me to the following link to turn off the pots.
http://www.futaba-rc.com/faq/faq-8u-q52.html

I followed the instructions using PMix-7 only to get a bizarre throttle curve that reversed at mid throttle. PMix-6 also looks like it would produce a bizarre curve.

However I was successful using PMix-5 to desensitize the channel 7 potentiometer. At –95% settings the full range of travel of the pot produces a few degrees of servo travel approximately equal to moving the control arm one spline. Using channel 7 to trim the #3 throttle effects the servo over the entire range of travel. Incidentally PMix-2 was used to slave channel 7 to the stick on the transmitter and two mixes are required for each engine slaved.

I have not been successful yet in desensitizing the pot for channel 6.
Correction: Channel 6 also works but there is a 3 click dead spot at low throttle. If necessary the dead spot can be fixed in other ways.

Details can be posted if they are needed. White coats have again been avoided.

Bill S