follow the book you may hear other methods but the right way is the one in the book .
I have the same engine and the thing is a screemer the reason for richening the needle is to cool the engine down through the break in procedure so you dont burn it in you break it in.
after the first runs fly it rich like the manual says your good to go, mine runs super.
one thing to do after every flight/run check the plug and all head bolts for tightness for at least the first ten flights mine loosened up a bit and I didnt notice until the engine was barely running I got it down after tightening the bolts and plug not any problems with this motor