[quickchange]

Couple of years ago we had the same problem with NEW top shaft , seems when they were machined out of round & one point reading was 5-7thou less than the other 3 ,contacted the supplier, they airfreighted another batch from a differant supplier , same thing , their 3rd supplier was able to send yet another batch of which checked out correct ,Mac,s often send me parts to check , So i beleive you have an out of round shaft where the rotor fits , We set them up with a dial guage kit i purchased at a National meet , Hope this helps , Derek from still wet NZ