Don, after about 200 mile break in, I started using only synthetic!! Use a good synthetic, and about 25% of your ratio use also castor oil. I've now only have 800 miles on 66cc/reed/etc. SYNTHETIC IS THE STUFF!!!!
PS: I run 25:1 (Read up on castor.....INTERESTING)
It doesn't matter what kind of 2-stroke oil you use, so long as it's mixed at 25:1 oil/fuel ratio; your engine will have a long and happy life (if it's not excessively over revved).
