Honda 20/50 Motor Oil in '82 R65LS

[Red_Hen]

Not to start another oil post but here goes -

I bought a gallon of Honda 20/50 m/c grade oil and put the proper amount in the crankcase after we re-built the R65LS engine.

Read a thread recently that the rating of the oil should be SG?  Not sure i said that right.  If memory serves me, the Honda jug says SJ.  

So, my Q is:  will this oil be okay to run in my bike or should I change it out?  Is BMW m/c oil the safest best for you?

[Rob Valdez 79 R65]

Any SG will do.  I have heard BMW's oil is Golden Spectro, which I guess is a good product.

http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1300736327

Apparently non-SG rated oils can be the cause of this: http://bmbikes.co.uk/photos/museumphotos/Cam%20Follower.jpg

Sometimes affecting the camshaft as well as the follower.

[benlawlor85]

I was always told any basic car 20/50 same stuff i used to use on my old MG midget, i use now. Was also told never to use motorcycle oil, due to the dry clutch. Seems to work. And on my 1100GS i use fully synthetic mobil one, costs a bomb but that bike never loses a drop between oil changes!

[nhmaf]

The issue with these older airheads is the metallurgy was designed when there was alot of ZDDP (zinc compound that I won't spell out here) which, if I understand it correctly, helps to form a layer on the metal and reduces friction.   As automotive engine technology has changed, this drives the formulation of the oil - hence now our new Subaru uses something like 5W-10 oil as well as our Mazda, and some even use "0W" oil with very different additives.   Without the ZDDP in the oil, these older metallurgy engines can be prone to more wear.   There are probably some synthetic oil compounds which can do the same thing, but I don't know anything about them.