Re: what type of 2 stroke oil?
IMHO the Chinese engines run best on racing oils. I've run Amsoil Saber, Opti, etc and I always come back to some racing mix. I like Amsoil Dominator the best, with just a splash of castor oil. Never leaves any residue that people tend to over worry about. I run 25:1 or 32:1, with one of the ounces castor.
My theory is: the loose clearances of these sloppy engines are more like racing engines than new tight tolerance production weed cutters.