If the throttle signal wire is giving the correct voltage (mine goes from 1v to about 3.8V) then I would guess that the phase wires are in the wrong order.
Here's the permutations I use.
Hall
Sensor
Wires
BGY BYG
Motor Wires
BGY BYG GYB GBY YBG YGB
Theoretically there are 36 permutations but the 12 above cover them all. All the others are just rotations of these.
I was lucky with mine, the colours matched what was already on the bike.


