Patience is the key. Make only one adjustment at a time and repeat the throttle tests several times before making any more changes. The slow needle on this engine has been fairly sensitive to adjust on mine, but I have found patience to be the key. Mine just seems to run easier all the time. Yours may (like mine has) taken a little run time to get happy. Mine now starts within about 3 flips virtually every time, and it will now idle down to 2000 and lower without fail. Even the transition, which used to drive me nuts, has become almost undetectably smooth. It used to cough and sputter quite a bit, making missed approaches sketchy. Now that it has about 2 gallons of fuel through it, I find it to be reliable to the point where I can do things that I wouldn't normally try. You will have to unlock the collar with the pin on it if you are going to make major adjustments. I found that mine would see a noticeable difference within just the width of the pin on adjustment. Just make sure that you count the turns in to seat it if you remove the collar before you make the first adjustment with the collar off.