cyl. sleeve dissintergrates into lower end - now what?

[rbm300ex]

I just had what described above happen to my built '00 300ex. The stock cyl. sleeve got pulled down into the lower case and partialy dissintegrated - sleeve works way down low enough that rings catch on top of sleeve and WHAMO on the down-stroke - alot of little iron chuncks & pieces in the bottom of the lower end & it locks up. I was trail riding normal and the thing just stopped. I thought I threw the drive chain at first, but nope, that was ok, got it home and thought maybe the cam chain was the culprit cause that I thought may have been the weak link as it was not replaced when I rebuilt. Well upon breakdown, it was clear what had happened - just as described. Searched the forums & have seen others had experienced this w/300ex motors but nothing mentioned re: fixing it.

Well, after all the above, I'm going to rebuild it again, I realize it will need a new piston, sleeve and the basics but what do I need to do to get the lower end cleaned up. Will it mean splitting the cases and cleaning everything or what - can it be done another way? Crank bearings? I realize some is determined by extent of actual damage but doesn't appear to be anymore than described. I'm wondering what the procedure is to begin the cleanup/rebuild. What would you experienced engine builders do? I have the Clymer manual to guide me into it too but never gotten into the lower end.
Thanks much-
Randy
:confused:

[416exriden]

yea if i wear u i would replace all the bearing in the lower and just to be safe. yea u would have to slit the case and i would take all the ebaring and parts out and put the case in the parts washer to take all the meatal shavings out the look for any spots that wear damaged when it blew. then replace all the bearings and put it all back toghather.

[rbm300ex]

Thanks for the reply.
Thats the way it is looking - splitting cases and cleaning out. I had'nt figured I would have to replace the bearings as it quit right when it all happened and cleaning them would be sufficient however i would inspect them and see, if they're not expensive to replace then I would, I hav'nt checked into costs of the crank bearings yet.

Anyone else?

Thanks
Randy

[bwamos]

I would reccomend the same. Split it.. clean it, and do a very very thourough inspection.

It only takes 1 small scar on a bearing to wreak havoc later.

[rbm300ex]

While I have it apart - anything else that should/could be done to help it out?

Thanks -
Randy

[rooster300ex]

I pulled the sleeve down in my engine the sameway you did. I think it is some defect in the stock cylinder after its bored. Or oil starvation.

[TWILES]

I heard of that happening to a 350 Rancher with a big bore kit but that sleeve got the krank and rod too.

[quad97]

New bearings are cheap compared to another engine falure!