What do I do at this point?

[400yzturbo]

You’ve reciever a lot of good advice, and I’m not trying to detract from it.

If it were mine, I’d ship the jug off to millennium technologies and have them repair it.  They’ll make it better than new.

also from the look of things from the pictures your cases are probably fine, but until you split them you won’t know for sure.

What typically happens is the piston self destructs and as the pieces fall down on top the crank they get sucked in and go around the crank.  Going around the crank has a tendency to push large pieces out through the bottom of the case near the front of the engine, or straight through the back of the case between the crank and transmission.

ive seen a lot of damaged cases and have fixed a lot, just don’t JB weld anything.  Go and get someone who can tig weld it and then machine it down and you’ll be back in business.

As for you’re setup, it’s not as bad as you think.  It’s still hard to swallow, but not unmanageable.

Best of luck.

Edited June 8, 2018 by 400yzturbo
Grammer

[solimine]

Looks like you stuck the piston then broke the cylinder and maybe the cases taking it apart. 

I've fixed some pretty messed up engines in the part, and could probably fix this one.  This is how I'd do it.

Split the cases, and set the gearbox aside.  Focus on getting the crank, rod and cases square.  By the looks of things, I'll bet the rod got bent. 

With everything apart, prepare the cases for welding then re-machine the critical surfaces.

Replace the rod if bent.

Sleeve the cylinder.

Clean up the head.

Reassemble engine with new crank bearings, wrist pin bearing piston and seals. 

You'll have a newly freshened engine... that will have that scarred up warrior look.

Note:  engines live longer when they run cool and are well oiled.

Good Luck 

[GCannon]

Learn how to let off the gas when you hear a funny noise.? instead of downshift and WFO!

Don't ask how i know

[Imposing Will]

2 hours ago, solimine said:

Looks like you stuck the piston then broke the cylinder and maybe the cases taking it apart. 

I've fixed some pretty messed up engines in the part, and could probably fix this one.  This is how I'd do it.

Split the cases, and set the gearbox aside.  Focus on getting the crank, rod and cases square.  By the looks of things, I'll bet the rod got bent. 

With everything apart, prepare the cases for welding then re-machine the critical surfaces.

Replace the rod if bent.

Sleeve the cylinder.

Clean up the head.

Reassemble engine with new crank bearings, wrist pin bearing piston and seals. 

You'll have a newly freshened engine... that will have that scarred up warrior look.

Note:  engines live longer when they run cool and are well oiled.

Good Luck 

I'd go with this, except for the sleeve. New-or used and replated-cylinder. Motor will be new, you'll know what you have. Wrench Rabbit kits are very reasonable. I have an '02 CR250R that was completely rebuilt last season. Cost me @ $800, but totally worth it. My two cents.

[400yzturbo]

Millennium technologies can fix your existing cylinder.  

Im having them fix a 98 CR250 cylinder that has a broken skirt, just like yours.  Jeff from millennium says they fix broken skirts all the time.

The skirt on yours will need repaired in order to sleeve it or to replate it, so why not just have them repair it and leave it  Nickasil.

Best of luck in getting it running again.

Here is my cylinder with a broken skirt.

[ozijake08]

move on buy a new bike

[sportriding]

edit

 

Edited June 9, 2018 by chuck12345

[ss-racing66]

On 6/8/2018 at 7:00 PM, hondaman331 said:

Im not seeing that the crank let loose. Thats a worn cast piston that shattered and i doubt the cases are junk. I doubt there is anything wrong with the cases at all. Send cylinder to millenium technologies with the head, get a new piston and i would replace the crank and mains while at it since the rod probably got buggered up from the incident. That isnt as bad as you think.

You don't think that rod looks discolored (toasted) ?

OP can prolly verify whether the con rod and crank still spin. I'm just guessing, but from looks of the discolored rod,  the crank bearings came part and debris started traveling, leading to a chain reaction. It's also possible that the cylinder skirt just broke off and started the whole affair.  Regardless, if I had a good-shape 06, I'd put a new engine together for it. 

good luck @Brap97

[400yzturbo]

Repairing what you have will get you back on the trail with less out of pocket expensive, than getting a new bike; especially one such is an 06 to present.

list of what you need to do:

-split the case and check the case for cracks.

-if no cracks present order a full bottom end rebuild kit such as a “wrench rabbit” or OEM parts if that’s your taste.

-ship your cylinder to millennium and have them work their magic on it.

-rebuild your motor

-ride

This way you know exactly what you have, rather than buying someone else’s bike and not know if or when it will pull this same stunt that yours just did.

If you do the motor yourself like I just suggested you’d be looking at $900 for it all.  Well that’s about what I’d do it for

 

[KDXGarage]

Next time, please put what year and model in the first post, please.

 

Repair and replate cylinder

split crankcase halves and inspect halves, replace used / new

inspect crankshaft halves and rebuild or replace

 

try not to spend money on anything besides the engine on the next bike before non-engine costs.

[Brap97]

[Brap97]

Those are the cracks I have found, both on the right half of the case. For those asking, nothing unusual on my end that caused it to blow up. Correct gas and mix, oil ect... must have just been worn but I think with what I read I am going to attempt the rebuild myself, however it’s a little intimidating getting into the bottom end as I have only ever done top ends. So I might come back with some questions here and there haha
Thanks everyone!

[EEE299]

The second pic just looks like casting marks to me. I don't know about the first...

[RK-REX]

First pic sure looks pushed out. 

Second pic, is hard to tell, the lowest one in the pic looks like a casting imperfection, but the one by the hole and the one above it are kind of suspect. A good DIY way to check for cracks is to clean it really good with carb cleaner or something, then soak a rag in diesel fuel or kerosene or penetrating oil and rub it all over the part so that whatever is on the rag squeezes out onto the surface and into the cracks if there are any, you can also just pour some on it too. Then take a dry rag and wipe all the diesel/kero off of the surface and dust it with talc powder or chalk dust. If there is any residual fluid left down in a crack, it will show up on the powder. I usually do it a few times to make sure I'm not missing anything. 

If you want to see what it looks like, just put a drop or two on a metal surface then dust it. It shows up pretty good. 

[Motox367]

Those case's not bad at all. I suggest you find someone who can weld . Learn how to get ot ready for welding and after weld. Heres some ive done