Your engine is foreign to me but I'm familiar with Z1/KZ1000 engines, which are similar. There are no thrust bearings on a Z1 crank. They rest on ball bearings, which means there should be no side thrust. Cases don't wear as far as I've seen. If your crank is wandering it probably means the rods have excessive clearance, and/or the pistons are wearing your cylinders. How is your compression?
I honestly cant remember if i had ever done a compression test on this motor. since you reminded me, I did a cold check just now and the numbers are abysmal. 60-70ish.
Ill be firing the bike up in a bit and ill do it again after a thorough warmup.
I often check compression on motors cold and hot, and have never seen such a low set of cold numbers on a motor that runs this good. I imagine the hot numbers gotta be a lot better but I will find out soon enough! Crazy to think if the compression really is that far down, how much faster this thing would be with good numbers. EFI really woke this thing up and I cant tell the engine isnt perfectly healthy by how nicely it runs.