Richen it a full 1/4 turn to start with. There's nothing wrong with running these big 2-strokes rich for the first 1 or 2 gallons. It is a little messy on clean-up, but the motor will run a whole lot longer for you. When you re-set the needle do the vertical test at 1/2 or full throttle, it shouldn't bog at all, it should try to fly right out of your hands. Please be careful on this test, I know I don't have to tell you this, but I always try to cover my bases.

Good Luck,

Ken