Wow! Thanks for all that replies guys, much appreciated. Sorry to not answer every single reply.
@Jakobi, Motorman and Jeff:
Definitely a problem I never had before. Never got a bike running like this one and I think I got most to 95% perfect :-)
However, I had a 250 and did not like it as it needed more attention though was more flickable and easier to ride. But the engine required a better rider than me. The G2, yes I had one already and it helped but made it harder to turn the throttle wide open.
Indeed I thought that gearing it taller could be a solution. Sure worth a try.
@cbutler: Overall after quite a few hours of testing with different needles I have to say I am happy with the NECW. Maybe it would make sense to try the JD-red in combination with the 40pj. I admit I never tried that.
@Hannes: I already added 140grams of flywheel weight. How much compression the GP head added I really don't know but the engine runs really nice. As you may have read I already closed the PV set up screw half a turn which made it a tad, but just a tad better. And yes, I rode it most of the time with the soft ignition curve, that really makes a huge difference
Thanks again guys!