83Sportfire Crankcase Question

[johndeere48401]

Tore my 83 Sportfire engine down, and found the crank bearings sounded a little dry when I roll them over, and it also appears that the O-rings are split and cracked on the center of the crank. When I split the crankcase halves I noticed where the roller bearings for the crank sit in the crankcase housing it was gulled up, and marred. Has anyone ever heard of this before? Do I need to replace the crankcase halves?

[JoeRainville]

Evidence of bearing rotation in the crank cases is considered somewhat normal. Some later Kawi motors have O-rings around the bearings, or molded in elastomer to prevent the outer race from spinning. I have also seen guys use a dab of bearing locker or Loc-tite to prevent rotation. Unless the cases are really chewed up, I would not replace them.

I hope this helps,
-Joe Rainville