Unless at your present setting the exhaust isn't blowing a lot of oil and unburned fuel, it's too lean. That's why you need to open a little more so that you can at least get max throttle to adjust for near max rpm. Does it burble stutter and die or just dies suddenly ? If suddenly, it's too lean. The forementioned pinch test will tell also. What about the glow plug ?
We'll save the low end needle for another thread.