I see what I think are 1981 and 1982 YZs - 81 with the scoop and 82 with the flat plate if I recall correctly.
I was running 80CCs until '83 when I jumped up to the big bikes but I rode with hosts of folks that had the '81s and '82s. My dad had an 82 YZ250 which I raced in the SRAC in 82-83 along with my 82 YZ80. Classic bikes!
Welcome to the site. Glad to have you aboard!
Scott