Originally Posted By: Hermann
It is probably an air cooled engine oil. SJ is pretty far back in approvals, I'm guessing at least 10-15 years ago. It probably has a lot of zinc(good) and a Group one base(bad). Unless it is in the larger jugs, the typical lawn mower oil is quite pricy per quart in my recent purchases.
It could be most anything. I see no reason why an SM oil wouldn't qualify as an SJ oil.