gad_fly

I have a 1979 or 1980 DT175. I'm trying to figure out which model year I have. The manufacture date is 6/79 but I'm not sure if that means its a 1980 model year or if it is indeed a 1979 model year. Also what type of oil do I need for my DT? My DT has been in a garage for about 10 years and I'm attempting to resurrect it. Thanks gad_fly