I got what I believe is a 1985 moto4 80cc the rear differential is broken I found this one on ebay will it work?

 

I have just checked an on-line parts list and both a 1985 Yam 80 and a 1987 Champ 100 seem to use the same parts for both rear axles. Best to check for yourself before shelling out $200 https://www.yamahapartshouse.com/oem...maha_atv/parts and according to the lists, the 80 would be a Badger. However I have come across Moto4 cast into the plastics of a 1980s Big Bear I used to repair, so that doesn't mean much.