I have replaced a few pumps last year and realized the thrust washer that comes in the rebuild pack is not the same size as the oem, its actually a touch larger. When I put the pump back together the prop would be extremely difficult to spin if not spin at all. I had no choice but to clean up the old thrust washer and use that. It doesn't seem like they get much wear. I have spoken with shop where I buy the kit from and they had known about the problem already and were supposedly fixing it. I think they get the parts from another place. Btw, the skis were from 98-02 951's.