my 06 topped out at about 50
I have gotten mine up to 110 mph but I dont have stock tires. So somewhere around there.
it depends what has been done to it but a normal cr125r would go 60 to70 mph they cant go too fast because a cr450 goes 80mph to 100mph
about 180mph with 150hp in the carb version (1997-8) and 164hp in the fuel injected (1999+) while not as powerful as a busa, still ridiculously fast and with better handling to boot about 180mph...
about 45