2003 YZ 250 cracked crankcase

[dgrizzz]

My son really did it this time .... Or did he? I bought this bike for him a year ago and all was well. Last time out he blew the motor on a long 4th gear wheelie. after a complete teardown I find small little hairline cracks in the crankcase. but it looked like it had yamabond spread over it. I didnt notice the crack until I cleaned it off. the case look's like the rod was hitting it but no marks on the rod or crank. So was this bike repaired and sold to me? and if so should I try to do the same repair again? Or should I try to clean and repair with JB Weld? The Cases are steep at 389 for one and 438 for the other. Any advice would be great. D

 

[tyler_43]

where in the case is it cracked? If possible I'd try and get it welded.

 

[Ol'89r]

the case look's like the rod was hitting it but no marks on the rod or crank. So was this bike repaired and sold to me? and if so should I try to do the same repair again? Or should I try to clean and repair with JB Weld? D

I agree with tyler, have it welded. If the rod went out at one time, it could have cracked the case at the bottom of the crankcase area. They most likely rebuilt the crank and tried to seal the cracks with yamabond.

Have it done right. Dont use sealer or JB Weld.

Where in Ca are you located? I may be able to recommend someone.

 

[dgrizzz]

New?

I think I am going to just get new cases if I can. I will check to see tomorrow. But just in case I cant get them I am in Cal. close to Sacramento (40 miles southeast) in a town called Sutter Creek. So if yoiu know someone that can do the repair great!! The crack is a hair line crack I can see from the inside outside of the bearing. It runs about an inch then rounds the corner at the top of the case. It seems so thin it shouldnt be hard to repair but what about warp from the heat on the case half's?

 

[Ol'89r]

I am in Cal. close to Sacramento (40 miles southeast) in a town called Sutter Creek. So if yoiu know someone that can do the repair great!! it shouldnt be hard to repair but what about warp from the heat on the case half's?

WOW! Sutter Creek. What an awesome little town. :nod: I envy you.

There is a guy in Peteluma named Mike Crowther that should be able to do it. He runs a company named Edco. Engine Dynamics Co. If Mike can't help you, I could weld it for you but, I'm in Corona in So Cal. If it is tig welded using the proper heat and proceedures, warpage is not a problem.

If Mike can't do it, PM or email me for an address.

 

[dgrizzz]

I ordered the cases today but I am waiting to see if they are available. If there is a problem I might take you up on your offer. Thank's!!