brown Stuff?
Rick,
On the Island, S&W should be available. They have some blends with very low castor and they have all synthetic blends as well.
A little castor is a good thing in a 4-stroke. Helps keep the bearings from corroding and provides an extra measure of protection to the rod journal. You only need 2% castor to offer you those benefits with the remainder of the oil bieng synthetic.
That's not too much castor where everything starts getting gummed up, a little staining yes, gummed up no.
Fuelman