JUST replaced mine this past Saturday.
First and foremost, watch the video on YouTube https://www.youtube.com/watch?v=AvK-5aQuhNs
Specifically, watch the part where it says to START the adjustment with the bar at the TOP, then tap on it until it just becomes visible in the center.
I must have watched that video 10 times before, but didn't quite grasp how important this was. I started with the bar at the bottom, then gradually moved the sensor by tapping (which was tricky with the hose/harness/crash bar in the way) until the line appeared in the center. Then, when I'd check to see at what RPM the bar would change to the top position, I found it not moving at all, even up to 4000+. So, tap tap tap in the other direction, check the bar rising, still not moving even at 4k rpm. Tap some more, bar now is at the lower position at idle. Start whole process over again. Repeat 10x times. Swear, and throw things.
When I went back and watched the video, I caught this subtle step. Tried it again, this time starting with the bar at the top, then gently tapped until it first moved down to the center at idle. Now, I checked to see what rpm it rose to the top, and much to my glee, it moved somewhere between 1600 and 1700 rpm. I gently, GENTLY tightened down the screws, checked it again, still rising at 1600-ish rpm, and called it good. Proceeded to drink several beers