1997 wr 250 problems. Help?

[fatcat]

i think the main berings are going out. i took the stator cover off and it has slight play up and down but none side to side are they shot? and how hard would it be to replace them myself?

[Grasshopper]

What happens is the main crank bearings and crank get oval in shape, thats what I've been told anyway. This happened to my '93 yz 250wr, I was riding along and suddenly died, no start. No spark started checking things and took the cover off and noticed right away my stator or (magneto) was turning freely by hand. The key that splines it to the crankshaft sheared off apparently from excessive play in the main bearings. On my bike I had to replace the crank cause the main bearing journals were to oval. You can repair the crank (weld and machine) if its not to bad, but a complete teardown is needed if you've never dug into the bottom end before it might be difficult.