makes a loud screeching sound when trying to start

Could be the bearing is gone in the end of the starter . Pull the starter and spin it while not engaging the engine to see if the screeching is in the starter or if it is in the engine. if its runs silent then the problem is in the engine if the screech continues when the starter is run when not in the bike means you need a new starter. Hope this helps

If it's screeching and not turning over the engine, then most likely the starter clutch is blown out. The part is available separately, and the starter motor has to be removed and disassembled to replace it.