Yup... You've learned a hard lesson about Watts per pound. Even at maximum output, that motor can't handle half enough power to fly a 2lb plane adequately. That motor belongs on a <16oz plane with a much smaller battery. Keep in mind that a "400" outrunner brushless motor is designed to have the same effect as a geared Speed 400 motor on an airplane.

The AXi 2808/24 as recommended by jooNorway is an excellent choice. You won't have 3D, but performance will be pretty darned well. This combo is common on the Wattage parkflyers from the same family as the Pitts.

Another option is the Eflite Park 450 outrunner. You'll want to swing at least an 11x3.8 prop to get the Watts through, though a 10x6 might work okay too. One thing you don't want to get too weighted down with is prop sizes in electric. The prop size may be very different than what you were expecting, so be flexible and finding appropriate combinations will be easier.