Nomad2day
Longhair Redneck Geek
Try what Brew is saying here.You may need to play with the adjustment to get it right. Backing it off a 1/4 is a good starting point. Try playing with the adjustment try backing it off a little more than 1/4. See if that helps! You may just need to find the sweet spot. If trying the adjustments dont help then you may need to open up the primary and check things in there such as the clutch hub nut for being loose. If not that then check the clutch dome hight and clutch pack wear limit...
Just tighten the jam nut enough to hold, if it still moves loosen it and back the Allen screw another 1/4 turn, tighten the jam and check it again. If it makes no difference then look in the primary side to see if the clutch nut has backed off from vibration cause it will move in and out on the treads. Be sure your clutch cable has plenty of slack in it when you do your adjustment.
It would not hurt to check your primary fluid level anyway and change it out if it has not been changed.