I have one and it took a bit of time playing with the needles before I got it running right. I used an engine test stand and ran the engine until I got the low end needle right. Then I started playing with the high end, running it first on the rich side and then slowly leaning it out. As I did this process I had to make a few adjustments to the low end. I noticed on mine that the low end adjustments had to be made in small increments. And the high end seemed to have a sweet spot and if I got away from the sweet spot, it did not run reliably. So, keep trying to tune the engine with small adjustments. Once you get is just right, leave it be.

JR