I believe Amsoil has the factory recommended blend, 10w-30. I usually use Castrol 4T racing oil, but not sure they have the 10w-30.
Yeah, I checked they don't have a 10/30w 4T product...To bad, it's great oil..I like it better then Mobil and Amsoil's offering. I loved the way my Sabre shifted using that oil..plus the engine mechanically was incredibly quiet...