JLC
I had a 1200 Sportster (2004 model) before I got a 883. It was fast
, the hot-rod of the Harley Family till the liquid cooled bunch came along.
The 1200 I had tore-up from doing 2000 to 4000 in 2nd and third gear trying to keep-up with a bunch of SAVAGES .
Best I can figure , the .0002" or .0003" of play in-between the Crank-shaft and the Drive/Alt. Sprocket must have increased with the up and down rpm's. The splines , simply "Disappeared" !
Well , there were traces of them in the primary oil when I drained it , so technically they really didn't "Disappear" , but they were gone when I looked to see why the starter couldn't turn the motor.
Same motor / 883 = 3" pistons / 1200 = 3.5" pistons + high test fuel.