I tied up a rod bearing on mine last yr, and that was a reman crank direct from Doo. I don't know for sure, but I would say not more than 2500 klicks on it.
My piston (also RKT) looks like it could be cleaned up and re-used, but I replaced both pistons and put the old ones in the new boxes. One is plenty good to re-use if the occasion presents it;self, but this one I wrote on the box "Maybe in a pinch".
Not worth puting in when you are replacing a crank!
Took me a bit to figger out what was going wrong with the sled when that was on it's way out tho. It would start and run fine, but seemed to bog down at higher R's. So I hopped on a trail and went to clean it out and the higher R's only seemed to make it worse. At that point I was just gunna be glad if it made it through the afternoon, which it didn't.
I thought that it was a main bearing as I am running the "grease seal delete" layout in my motors, and figgered I got bit. (Lost mains 2wiced that were in original greasepack, so I tried something different) Turned out the mains were fine, and the rod was what tied up.
(So - not related to the "no grease" setup)
.