Are these cracked yz250f cases still usable?

js548
Posts
1
Joined
7/16/2026
Location
Stuart, FL, USA
Edited Date/Time 7/16/2026 8:07am

IMG 7184 4IMG 7188IMG 7189.png?VersionId=Efe4Q7KtMPj5R1KCHx22cz4IMG 7190Hey guys! So need some opinions. I was rebuilding my bottom end on my yz250f and I stupidly put a wrench around a thick towel inside the crank to stop it from moving to torque the primary gear down on the crank shaft. I had to loosen it again so I put something on the rear side inside the crank. When I loosened it I heard a pop and crack. It happened to be these little wall things from the main cast that goes in between the transmission gears and the crankshaft. The other side you can see that is cracked I got off clean like the other side. I opened the motor back up and there’s no random pieces inside. Also the walls from the cylinder head go down in there as well to separate it some more. No more cracks anywhere else. Should I still be okay to run it like this? I know I could have it TIG welded but I heard doing that to a cast can not be strong. Would be afraid of it breaking off in the bottom end. It also doesn’t split up the oil obviously because it goes right under it. I am assuming it was for more added strength and to protect the transmission in a crank failure. I can also send more photos of it if needed. The one photo is how it is supposed to look.

Just run it or? Thanks

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btroxler
Posts
172
Joined
5/22/2017
Location
Saltillo, MS, USA
7/29/2026 2:36pm

Yes, that also can easily be repaired.

 

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