Joel, I am using a point-at-it IR Termometer from Radio Shack. I use it when I am troubleshooting aircraft engines - looking for a cold cylinder. Rather than the old way - putting your hand on each cylinder head cover and which ever cover does not leave flesh on it is the bad cylinder. Now I can just point and click and see which one is the coldest - indicating which cylinder is not firing.
I can build an airplane from scratch (I've built three of them - all aerobatic hot rods), but I am only a shade-tree mechanic when it comes to motorcycles - all though I did work in a BSA shop all through my high-school years - I sure loved my 441 Victor - and I still have the scars on my shins to prove it.
Like everyone else here, I am just guessing - shooting in the dark for some kind of answer to this puzzeling question of stator failures. I wish BMW would put one of there engineers on the problem.
I'll let you know in another 50,000 miles if this heat tape fixed the problem - or sooner if it don't.