Seems more likely that dirt or something else got into the cylinder and caused those marks. The YZF has a nikasil cylinder, not much can be done for damge done to it except for replating the cylinder or getting a new one if the damage is beyond limits.
A timing chain will not cause that damage. If your timing change was loose enough to cause damage, it would have skipped time and you would have bent valves.
Buncha dirt bikes with license plates.