Source: https://atcvin.webs.com/
It's an 83 ATC185S frame if I typed the numbers in right. You can double check the harness, the tail light connectors on the main harness should be both double female terminals, 83 was the only year with the old style CDI plug and those tail light connectors. I can see the CDI plug in the photo so it's 80-83 for sure based purely on that.