I'll bet that the stator is loose in the can........I have seen a couple now with this problem, nice actually because now you can adjust the tension you prefer on the sensor adjustment tension. Carefully tap the complete motor on the bench, towards the sensor/bullet end if you want tight, towards the pinion shaft end if you want loose. Of course do not hit shaft or sensor plug! When set to your liking, VERY Carefullly wick ca glue into the vents as to glue the fiber boards to the can. Tip the motor so the ca runs down and around to the fiber board, just don't get stupid with the ca, a little is all you need.
The newest motors are so tight in this area you have to damn near take them apart to adjust timing. Yes I have banged the snot out of some newer ones, and they do not move, so I guess "they" solved the loose stator issue.
Got T-Bar ? ......... Oregons No ZigZag rule sucks
Bias the weight to the end you want to hit the wall with first!
Searchin fer answers in the Fog.......that's what I found