Rebuilding cranks is not super difficult, and the tools needed are not so high tech, but experience pays huge dividends. It's about knowing where to tickle it and how hard.

Ive got a dedicated NSR250 crank jig, which allows me to press the centres together with the big end pins in perfect alignment. It's fascinating that you can take a brand new crank, pull off the out wheels and then find that it doesn't fit in the jig because it was pressed together at the factory out of alignment. Hmmm.

To true up the wheels you need to know what the dial gauge readings mean, and then where to "adjust" it. You also need to know when it's time to call it quits.