If the motor is 19-27T it should have a notch in the can and matching tab on the endbell so the timing is fixed and can't be adjusted. If its a mod motor, check the timing before you take it apart. I'd suggest using a sharpie or a dab of paint to mark both the can and the endbell so you can line them back up - it's really easy to put the endbell on 180 degrees off causing the motor to run clockwise rather than counterclockwise (looking at the output shaft, not the endbell).
If the motor is getting hot it may also be that the timing is advanced too far, if so you'll want to set it back to 10-12 degrees to start with. If your endbell has multiple notches, use the one most closely lined up with the screw to set your timing to the marks on the can or label.