I've never had much success with the auxilary APT models without removing the aux power piston and metering rod and recalibrating them.
That system isn't that great, and adding fuel from the APT feeds fuel under the jets clear across the load/speed range. It's better to re-jet, and new metering rods, so they are very, very close, and add a tiny amount from the APT system, if/as needed.....Cliff