Wings, just for jollies, try this:

Disconnect the collar that is on the low-end needle. With a small screwdriver, close the low end screw completely, then, reopen it 1 and 1/5th turns. Now, set the collar to the mid adjustment point, and reconnect it.

From the factory, that low-end needle is supposed to be set to 1 1/5th turns open. But the one that I had for a review was set wrong from the factory. Once I set it correctly, it ran like a dream.