Sibling explanations are correct re: direction of rotation. As to your second question, the flywheel keeps things spinning so it doesn't lock up and has the mom

Sibling explanations are correct re: direction of rotation. As to your second question, the flywheel keeps things spinning so it doesn't lock up and has the momentum to compress the air/fuel mixture. BTW 0 degrees is called top dead center or TDC and is a useful point for calibrating timing and ignition.