Premium at the minimum mixed with a quality premix at 32:1

4 oz of oil per gallon of gas

The safest is to start it, run it for 5 minutes let it cool, do it again for 10 minutes let it cool, then 20, 30... Then start riding it easy at first, doing the same routine time wise. Then after all that then it's time to hammer. There are other ways of breaking in motors but this is the safest.

Run the fuel at the same ratio all the time. Store your fuel in metal cans as plastic jugs are porous and bleed off the explosive stuff in the fuel, which isn't good for your new top end.