Ok, I tried again today. I finally got the engine to run lean. Had to turn the lowspeed needle in to 3/4 turn and the highspeed to 1 turn to accomplish this.
Got a maximum Rpm of 7800 with the lowspeed at 1 turn and the highspeed at 1 1/4 turn. Idle is about 1900-2000 RpM with the butterflies completely closed. Thanks for the tips!

Next will be fabbing up some tuned pipes. I did some calculations and arrived at a pipe that´ll be way to long for the application this engine is going to be used for. I´m thinking of doing a little experiment and try to make a pipe that´s tuned for half the frequency of the engine (so the pressure wave has to travel op and down the pipe twice)
Has anybody got any experience with this?

@tim220225: I expect you mean some shots of the internals? We'll maybe when I start fiddling with the porting. I've assembled and dissasembled this engine a couple of times too many to get to this stage. in the mean time, here's an exploded view from the weedwacker's manual: