I have an older 250 xt 1980's but can...

Hi
Did some extensive searching for you. You may need to call an old school Yamaha mechanic to pull that one up for you. Tpo give you an idea of what was being produced back then, found this list ...
XT 250 G 80-81 3Y3,5g4
XT 250 G 80 3Y4
XT 250 H 81 3Y1
XT 250 J 82 15Y
XT 250 J 82 3Y1
XT 250 J 82 3Y4
XT 250 K 83 3Y1
3y2 does not appear anywhere. But the series of number indicated for the XT250 above point it to probably being an XT built between 1980, and 1983. Best I could find. Hope it helps
regards robotek