I also have an evo .46 that was acting up. You could put it at full throttle and it would take 2 or 3 seconds or more for it to reach full
rpm. I ran fuel thru the high needle (took off the line to carb) to clean out any dirt. It transitions better now but still not as good as my OS .46's. My high needle at one point I had screwed out 5 full turns and it acted like it was opened by only half a turn. You could see the needle turning by itself on full throttle!!! I had to adjust the little ratchet on it.

Dave...