sounds like your bushing isn't the right length? doesn't take much tightening to keep mine from spinning, but mine was from the initial test.

if you loosen the axle is there a gap(slop) between spacers/bushings?

Kohburn, Here is the measurement. I think the best solution is some locktite between the axle bushing and the sending unit sleeve. What say you?

On second thought, if the sender is trying to turn, the axle bushing likely is as well....

Got mine yesterday. Hopefully I'll be back in the swing of things tomorrow to get to this.

EDIT:
Well, I was able to get up and around and get to this today. Everything went very well. The only thing I almost changed was to get rid of the little blue/white stripe pinch connector. I've just had bad luck with those in the past but I went with it anyway. Just my paranoia. I'm sure it will be fine since it's not under a truck like a trailer harness gathering weather and mud.

Wheel sensor: I had no problems mounting it. The wheel spun when I torqued it to spec. My only concerns were that there's no nub to hold it anchored in place like the stock one (see pic). Somehow, someway, by "FM" it stays in place when torqued. I also found that I had to rotate it up (about 12:00 o'clock) and mount it just forward of the fork leg (see pic). If I didn't, it would press against the fork leg and I didn't want that sideways torque on the sensor.

It works great! A fine looking product and Mrs. 2LZ loves the display. Classy setup.
Thanks mjstef!

I installed mine today as well. The sensor wanted to sit in the same place as 2lz. Whwn i was done, my front wheel was rubbing on something, similar to what was reported by PNWdualrider. For me , it was the brake pads. To fix, I removed the caliper, spread the pads with a screwdriver and remounted it. Works now with no rubbing. One thing though; when I pulled out the axel to mount the sensor, the aluminum casting that fits over the fork, that the axel goes through etc, rotated around the round fork tube pretty freely! I looked under with a mirror and saw a hex nut but it would not tighten. I've taken front wheels off of moto guzzis, suzukis and hondas and have never had this part move. Is it ok for this part to move/rotate around the fork? Thanks Matt for a really great part.