I’m not sure what the X30 specs are with respect to what is allowed to be done to them, BUT we do run Leopards with the WKA/WKC road race series.
With WKA road racing, you more or less can NOT touch anything. With our new MY09 Leopard, Brian Fisher pulled the crank a to make sure it was square, gave it a couple more thousandths piston clearance, and set up the carb. The thing runs great and has won it’s share of races. I believe Brian charged us a couple hundred for his labor.
I would expect a TOTAL rebuild on a well worn engine would run you a $1000 or so. But you’re replacing a bunch of parts and doing a total tare down and rebuild!!