Dual brushless motor questions

[BrianG]

IIRC, you have to sync them up so the back-EMF pulses are in sync. I believe this involves putting a AA battery momentarily across two wires to rotate the rotor to a set position. Then do the same to the same two wires of the other motor. Then hook each respective wire from each motor together. And finally hook them to the spur. Do all this without changing the rotation AT ALL. Kind of a PITA IMO.

You are effectively halving the coil resistance so instead of say, two 8-turn motors, you are running the equivalent of a single 4 turn motor. You'd have to be very careful with gearing depending on the motors you are using.

Personally, instead of spending $55 x 2 for the motors you linked, why not get a single properly-sized motor?