[Espeefan]

Izzy, some motors do have a polarity mark on them. I've seen positive symbols on the terminal that is intended to be positive, but in general, this is rare.

As for normal forward rotation, treat the motor like an internal combustion engine. Holding onto the can, with the motor shaft pointing away from you, and you looking from the rear of the motor, forward rotation will have the motor shaft spinning clockwise, just like a crankshaft would on an engine. If I am unsure on the polarity of the terminals, I hook some jumper wires to the terminals and watch to see what direction the motor spins.

Now, motors don't really care what direction you run them in. They don't know the difference, unless some timing advance is thrown into the mix. A motor with zero timing has no care in the world. A motor with timing advance will run better (stronger of faster) in one direction then the other. If a motor has fixed timing, then you are pretty much stuck with what you get. A motor with adjustable timing will spin happily in either direction, as long as the timing is set to zero, or advanced in relation to the direction you want the motor to spin.

Now as for adjusting the timing, you can rotate the end bell of the motor so far that you will actually reverse the motor direction, without changing the wire polarity. If you need a motor to spin the opposite way, do just that. If I remember right, you need to rotate the end bell 180 degrees the opposite way before you have effectively reversed the rotation. If in doubt, loosen the screw that holds the end bell in place and rotate it. Apply some throttle and see how the motor reacts. You can also do this with the motor running and observe it's RPMs dropping off, if you are adjusting the timing the correct way. You won't harm anything by making adjustments on the fly, but you can also leave the ESC 'on', make a small adjustment, and then give it some throttle to see how the motor reacts. Adjust the timing far enough and suddenly the motor will rotate in reverse. You can continue to adjust the timing to get a little power, in it's now reverse rotation direction.

Play with the end bell's location until you feel you have the timing set to where you like it. Either equal speeds in forward and reverse (of the model), or a touch more speed in forward travel. You really cannot screw anything up.