Its only "similar" to the dio, its a derivative of both the US AF16 and the Dio AF18e. Small things like the carb intake(which a af16/18 one will work), Rear pulley/driven pulley, starter, cdi, and stator assembly are particular to the zx50 engine as well. You can not use the after market gears made for the AF16 or dio on a zx50/sc10a engine and the belt is not the same either due to increased crank case length for the 12" rear tire. Cylinder kits, variator, clutch, carb, intakes, reeds, exhaust from the af16/18 will work on it though. You can follow the link in my signature for a couple possible things to do.
At 11k kilometers its only really at 5k+ miles as its in KM not miles.
With 100 psi it should still run and go ok, it is at its serviceable limit though. I would also look into cleaning the carb.
Best of luck to you with your new zx, when it runs right youre going to love it.