2003 wr450 locked up. removed head/jug pics and some questions

[01bullitt]

hi, I just picked up a street legal wr450 that was locked up. I removed the head and jug to find this. crank seems to spin freely (starter is still mounted). it has a hot rods crank in it stamped 621, no idea what piston was in it, and it has yz450f stage 1 cams. how would I go about seeing if it has a 03 crank or a later model crank. im trying to figure out how I can check the crank to see if its bad, and what parts would you all recommend replacing with. im new to wr 

[01bullitt]

any ideas on what could have caused this type of failure, never seen a piston flip in the cylinder before

 

[01bullitt]

when I took the clutch side case cover off there was aluminum pieces all in the basket, and a recluse clutch setup. looks like it beat up the inside of the basket and possibly aluminum passing thru the motor caused the failure?

[01bullitt]

[bikedude987]

Something wrong with the rekluse setup for sure, but that shouldn't have caused that failure.  More pics of the piston please?  My initial guess is the piston had a ton of hours on it and rocked in the bore enough to catch.

 

And: What the heck is going on in your cooling system?! Orange in pic 1

Edited October 19, 2015 by bikedude987

[01bullitt]

Something wrong with the rekluse setup for sure, but that shouldn't have caused that failure. More pics of the piston please? My initial guess is the piston had a ton of hours on it and rocked in the bore enough to catch.

And: What the heck is going on in your cooling system?! Orange in pic 1

The marks on the piston are from me when I tried to beat it out of the jug, after i had removed the wrist pin and took it off the bike. I thought maybe the shavings from the clutch had something to do with it failing. The bike had no coolant, just water in it.

I guess I'm going to have to split the case to get all the shavings out of it, just hope it didn't damage the crank or rod. The guy said he only did about 20 miles since he put the clutch in, but he also said bike road fine just didn't start one morning so he didn't know what could be wrong with it

[knuckleduster271]

If it were mine I'd do a complete rebuild again. No way I would reassemble any of that with all the metal that was in those cases.

[01bullitt]

If it were mine I'd do a complete rebuild again. No way I would reassemble any of that with all the metal that was in those cases.

just crank and piston you mean right. or would you rebuild the top end to

[knuckleduster271]

I'd replaceevery bearing in the case halves and clutch assembly at the least and take the head completely apart for inspection and cleaning.

[bikedude987]

Agreed.  Split the cases, all new bearings, rebuild the crank.  It looks like the little end has a nick in the bushing anyway...

 

Looks like you may have broken a ring, which caused the lockup.  Might be the other way around, really hard to tell causation now.

[DPete]

Wow! that's messed up, never seen a piston crossways like that before