Low needle for sure. But which way is the question. If it stumbles and smokes...but eventually gets up to RPM it's rich. If it just hesitates with no smoke, it's lean. From your post sounds lean but I'm not there to see and hear it. The way to adjust your low needle is to first set it rich...about 1 1/2. Then keep leaning until it no longer transitions (maybe where you are now). Then just richen it up a tiny bit at a time until you get a very fast transition. Then it's perfect. The key is to find that lean/rich point and adjust it a little richer for the fastest transition possible (acceleration).