my 91 would drip oil from the se air cleaner ' for years' only when you ride it hard tho and i changed 'everything' lol finaly i ran it with the air cleaner off and found it pushed quite abit out of the breather bolts. now idk if this was the right thing to do but it definatly helped.
i took the washers off the breather bolts so the bolts sit further into the heads , not much mind you, but did help. it still breaths but the flow is less. like i said idk if its the proper thing to do but it dnt cost nutn to try . just make sure the bolts dont bottom out or seal up the flow ;-)
they do make breather kits but i ddnt find one that fit nice
peace