To my suprise when I had to replace the crank seal on the 1998 2510 I just purchased I noticed that the crank had some play in it and the crankcase looked like it was chewed up a bit. I pulled the sidecover. Sure enough the crank and the sidecover were both chewed up. Apparently Kawasaki decided that the steel crank didn't need any bearing other than the aluminum side cover...
for the parts cost alone I could drop a v8 in this thing.
I'm considering having the crank and crankcase machined so I can install a real bearing. Anyone else out there have any ideas? A real bearing might make this thing bullit proof

 

Gas or Diesel?

 

If it was gas, a 620D motor, there was a bushing on the cranshaft originally on the drive side and the flywheel side only had a machined cover. With proper oil pressure the flywheel side shouldn't have given any problems. Dirty oil will also lead to failure of this kind. I don't believe that after machining the relief for a proper ball bearing, you will have sufficient metal left to avoid catastrophic engine failure if the cover cracks and the bearing drops down outof place at 3600 RPM.
My 2 cents
Jody