More help splitting cases

[Tom H]

I am on my first time splitting cases on a '90 KDX 200. I bought a fly wheel puller, and got it off. The right side and left side are completely stripped of stuff and bare. (Probably removed more than I need to), I got all 10 crankcase bolts out, and I can't just get the cases apart. The tranny area splits a fraction of an inch, but the crankshaft area seems glued together. I have held it in the air had my son rap on it with a rubber mallet, but it don't come apart. I am too chicken to try wedging a pry bar in between the cases, although I suspect you could do that at the motor mounts without causing severe damage. The only thing I can see that I haven't removed is a snap ring on the clutch side of the counter shaft, but it appears the sprocket side of that shaft should pull free.
I figured I better stop and ask for help before I do something stupid. Anybody got an idea what I should do next?
Thanks

 

[jaguar]

I just did mine. what a pain!
I used a harmonic balancer puller and wound up having to beat on the center post with a hammer to get the cases to split little by little (it took forever). It wound up deforming the end a bit, so I'd recommed using hardwood on the end and beating on it.
The fit of the crank and bearings is too tight to be able to pry the cases to get it to split apart. You'd just damage the cases.

 

[Glitch]

Tom, dont pry, it could mess up the crank and the sealing surface between the two cases, even if you are extra careful. You should use what jaguar used, a harmonic balancer puller. If you have a manual for your bike its got step by step instructions on how to split cases, and it says to use a harmonic balancer puller.

 

[Tom H]

(I checked at all the local shops today, & no one had a manual. I'll order one but that will take a while. I thought this would be a lot easier than it is)
In the meantime, I think I tried something similar to what you are suggesting. I took a piece of 1/2" plywood , 8" square, and drilled a 5 hole pattern to match the ignition case bolts. I drilled a hole in the middle of the plywood for the crank end to go through, and a couple more holes for a gear puller bolts. I bolted the plywood to the case via the ignition cover bolts. I made the gear puller pull the plywood (& attached left crankcase) away from the crank.
I was able to reef on things pretty darn hard and straight, in a seemingly safe manner, but it still won't split. I banged on it every which way with my rubber mallet, and it is still stuck together! It is seemingly stuck at the front of the engine as I cn see minute cracks the rest of the way around (Yes. I am sure that got all the bolts out). I am afraid to reef much harder.
Is this similar to what the manual says to do? Anyone got a hand gernade?

 

[WaltCMoto]

This was my experiance on a 97 kx250.
the main bearings ( for the crank) are light to medium pressed in, so you take a small home propane torch and heat up the case on the outside where the bearing is so the aluminum heats up and expands, releasing the bearing. Dont try to get them red hot, just 5 minutes moving the torch around will do. aluminum growes pretty quickly with heat. Then when its hot, pry the cases apart carefully as so not to damage between the cases.
hope this helps.
Walt

 

[jpm200]

It could be corrosion in the case alignment dowels. My 89 was slow to come apart.
With the tension on the cases spray some penetrating oil where it appears to be stuck. Leave it overnight and try again. A little heat may help as well.
Don't be scared to crank on the tension as long as you have the 5 bolts deep into the cases.

 

[Kawierider]

I jsut split my cases on my 85'. I made puller and bent it....I ended up using a big huge thinck steel puller to seperate them....and it still wasnt easy...On my bike the bearing stayed on the cranck and pulled out of the case. I then had to have the dealer press it out of the other side of the case while they rebuilt the cranck. the same thing happened over there too.
Buy a good quality, thick, thick steel puller. make sure that you screw it in evenly on both sides. Then tighten it down. I used a rubber mallot to tap the shafts in the trans and the cranck to make sure it didnt hang up on the seals.
Make sure the cases seperate evenly to ensure they dont crack.
Have fun, jsut be careful, good luck
Tim

 

[70 marlin]

Try the kawi tool. Best $$$ I ever spent. Any other way you’re flirting with disaster!

 

[beefking]

I made a puller for my 89 out of a 2x6 block of pine. 3 holes for the ign. cover bolts, and one in the center. In the center, take a LARGE bolt (M12 worked good) and stick it through the hole in the middle. On the other side, put a few thick fender washers over the bolt and then thread the nut onto the bolt.

Next thread some extended bolts into the ign. cover holes, and leave enough room between the block and the cases to access the nut you just threaded on.

All you have to do from there is hold the nut with a wrench and crank that bolt down. The nut will go up against the washers/block, stopping it, then the bolt will thread down onto the crank... Of course a little heat around where the bearing is seated helps. Also, I put a little silicone on both sides of a nickel ($.05) and stuck it onto the crank. This protected the crank and lubricated it as well.

You'll hear a few loud snaps, this is usually a good thing (just the bearings poppin out, or the bolts snapping...either way.)


Good luck, hope this works for ya! :thumb:

PS total cost was not even $5 for hardware, plus the nickel was destroyed.