What kind of oil do i put into my 1974 mt250 honda in the crankcase for the gears?

i know that 2 cycle goes into the oil tank but not what goes into actually engineWhat kind of oil do i put into my 1974 mt250 honda in the crankcase for the gears?
I have been using Amsoil 20/50 in both my crank and primary. It's expensive, but I was told it was well worth it. I tried something else last oil change and I got all sorts of top end noise that I never heard before, so I am going back to the Amsoil at the next change. I don't know what grade you need, but I'm sold on the product.





That's a cool and rare little Honda you have. They sure didn't make many 2 strokes. I bet there aren't too many survivors out there.