Over-revving can cause engine damage in several ways. Firstly, it can cause the engine to overheat, as the increased revs cause the machine to work harder and generate more heat. Secondly, over-revving can cause the engine to 'redline', which means that the engine is revving so high that it is in danger of damaging itself through excessive stress. Finally, over-revving can cause the tires to burst, as the increased friction from the increased revs can cause the tires to overheat and fail.