bustedknuckles

Ok, so I just got an old DT and it is in rough shape. I finally got it running but I have a question about the gearbox breather. Is it supposed to be super loose and easy to take in and out? It seems to me that it should fit a little more snug, because right now I think it could easily get water or dirt etc in it and it could probably even shake loose? Any thoughts? Also, any links to a manual? Thanks