Be wary of what your cousin told you, part in hand or not... It would be alot of work to open the motor, inspect and diagnose shift fork problem then close motor back up before getting new part.
See where i'm going with this..? Im not picking you apart just tryin to look out for you, as I am in the middle of case split and tranny job on my K5. What I "thought" was the problem was indeed the problem along with 3 other parts in there that I would have never guessed. It was kind of like one little problem caused another then another, ect.
Well $300 later its finally going back together. That doesn't include all the little seals and gizmos "you might as well replace while your in there" expense.
Dont be scared , just be prepared....
Remember , the proper flywheel puller, a case splitter, a soft deadblow hammer, and a little patience, be careful not to strip stator plate screws and take note of stator position before you remove.
If its gonna be apart for some time waiting for parts, coat exposed parts with oil and cover with saran wrap. the internals will rust fast if not. (especialy the crank end ignition side)
Tapping on sprocket shaft with deadblow hammer while using case splitter will help cases come apart evenly. I log alot of hours on my 500 so I split the cases once a season to maintain whatever needs it. Once you do it you will see the KX500 motor is really a simple motor and tearing into the bottom end isn't so bad.
I hope this helps, Good Luck
