Here is a problem that veteran engine guys will laugh about.
However, for the uninitiated, this can be an intimidating situation.
You need to replace your crank shaft.
So, you have removed your engine from your bike.
You have removed all the bolts, springs, snap rings, cylinder, linkage, ect from your engine.
Here is what your are left with.
In this case, I used a 93 KX500 Engine.
Some guys will grab a hammer and start beating the transmission shafts to split the cases.
While this can in some situations work, you always take the chance of damaging your shafts, cases, gears, ect.
The solution is to buy, beg, or borrow a engine case splitter.
This one is a Motion Pro but there are many on the market that work just the same.
#1 rule. DO NOT BE IN A HURRY.
Engine cases are expensive and can easily be broken.
Before you get started, take the time to clean the threaded areas carefully and even run a test bolt or chase the threads with the correct size tap if required.
Oil all the threaded rods, set nuts, and threaded holes.
Next, assemble your tool.
Slip the arms onto the main shaft.
Then hand tighten the set nut.