A fourteen ounce tank is an excessively large tank for a TT .40 Pro especially in a trainer besides causing a greater CG change during the flight to the rear it will also change fuel head pressure during the course of a flight causing needling changes and its doubtfull you consistantly ever be able to use all the fuel.

A more reasonable tank size for the .40 pro is eight ounces and no more than 10.

John