My DA was doing the same thing and as I started leaning out the engine the condition stopped. I started leaning it out as soon as the problem started and with in a few flights the problem went away. I turned the low end needle very little at a time 1/16 of a turn more or less. Now that I have 6 gallons though it, two with 100-1 the engine runs purrfect. Try leaning out the engine to start before making it too complicated.

One thing I can say about DA customer service is they respond to your questions and concerns. Ultimately we need to figure things out for ourselves and RCU has the forum for it.

Good luck.

BG