Did I Blow My Top End or Bottom End?

[MXonaKawi]

My bike suddenly died on the track today when riding. It bogged on the face of a jump and then shut off completely. It would not kick over and the kick starter won't even move past 10 o'clock. The piston is completely stuck in it's position. The piston and cylinder appear to be in great condition though. It's the rod that seems stuck and won't move. Any advice or pointers would be greatly appreciated.

Dirt and metal debris I found sitting atop the piston.


Metal shards sitting below the piston (on the crank? I think it's called).

[sandblaster]

If you remove the cylinder you should see what happened.
It's hard to see much of your cylinder but my guess is it's time for a top and bottom.
Get that cylinder off and let us know what you find.

[MXonaKawi]

If you remove the cylinder you should see what happened.
It's hard to see much of your cylinder but my guess is it's time for a top and bottom.
Get that cylinder off and let us know what you find.

Sandblaster thanks for the reply. My top end is brand new. I just put it in 2.5 months ago when I finished the rebuild. The cylinder looks great and the inside feels smooth as ever, no visible scoring. The piston looks pretty much the same as when I installed it too, with just some slight signs of wear all around but not in any one spot in particular.

I've still got the piston attached to the rod, but it won't budge. The rod is stuck and as a result the kickstarter obviously won't budge.

I'm wondering if that metal circle type debris pictured above is a piece of a broken thrust washer from the connecting rod.

[Foxx4Beaver]

I've still got the piston attached to the rod, but it won't budge. The rod is stuck and as a result the kickstarter obviously won't budge.

try taking off the magneto cover, and grab onto the flywheel and try to rotate the motor backwards...I've seen a lot of guys have good luck doing this with a locked up motor.

[DoldGuy]

Looks like a thrust washer debris (copper in color). Check the big end rod bearing should be a thrust washer on both sides of the rod. Lucky no top end damage!

DoldGuy

[Flattracker]

What year and model is your bike? I have a 98 kx250. After 3 years trail riding then 3 racing my big end rod beading melted. The photos aren't showing up on my phone but it sounds like the same failure.  Likewise my top end had no damage other than dents in the cylinder head from bearing shrapnel.

[MXonaKawi]

Well thanks to Foxx4Beaver I was able to remove the magneto cover and free the stuck piston. It moves freely now and while I was rotating it, 2 more pieces of metal debris surfaced. They are pictured here. I'm guessing it's shrapnel from the thrust washers or rod bearing.


If that's the case, it seems I have two options:
1) Buy the Hot Rods Connecting Rod Kit for $100 and hope that solves the problem.

2)Buy the entire OEM crankshaft assembly for $250, gasket kit for around $40, and crankshaft bearings for around $30 and have complete confidence that my bottom end is perfect.

Which do you think is the best solution?

My bike is a 2000 KX 125.

Here is quick video of where I'm at currently in regards to motion.
View My Video

[bens87braap]

probably not a good idea turning the engine over with the piston slapping around like that

[sandblaster]

probably not a good idea turning the engine over with the piston slapping around like that

I didn't want to say anything but I felt a huge pucker when I saw that... 

[MXonaKawi]

probably not a good idea turning the engine over with the piston slapping around like that

I didn't want to say anything but I felt a huge pucker when I saw that... 

Yea I definitely won't make a habit of that. Do you have any suggestion on which of the two aforementioned options I should take?

[sandblaster]

aforementioned?
Too many syllables for me 
I'm all about doing it right.. And I'm not a big Hot Rods fan.
Since your splitting the cases, check your trans bearings out especially the out put shaft bearing.

[MRDART]

If you can afford it, the complete crankset is a faster way probably, but a properly rebuilt crank should be just as good, if not better since the factory might not be as anal about the trueing of the crankhalves as a good mechanic is...
 Oh and do replace the mainbearings and seals, might have debris embedded in the bearings that can cause another failure...
 Hope you get it running soon

[Foxx4Beaver]

Well thanks to Foxx4Beaver I was able to remove the magneto cover and free the stuck piston.

 

[Flattracker]

I rebuilt mine with Kawasaki parts complete crank, bearings, seals, trans bearings and top end. One year racing on it  and rock solid reliable. I would recommend OEM. Also my rod moved so much that it contacted the bottom of the case and embedded some steel that I had to remove.

[MXonaKawi]

I rebuilt mine with Kawasaki parts complete crank, bearings, seals, trans bearings and top end. One year racing on it  and rock solid reliable. I would recommend OEM. Also my rod moved so much that it contacted the bottom of the case and embedded some steel that I had to remove.

Ok, well I think this may be too big of a job for me to do myself with the exception of the top end. I'll probably bring it to a mechanic or shop for the bottom end.
So to be clear. I will need to start with part #13031-1465 from the Crankshaft/Piston diagram.
As far as the bearings and seals and trans bearings, I'm completely lost. I'm a bit out of my league when it comes to the Crankcase diagram.
Can anyone point out the part #'s for each?
I'd like to order all the parts myself and then bring them all with the engine to whoever I choose to do the work on it.

http://www.motosport.com/dirtbike/oem-parts/kawasaki/2000/kx125