hi evan. i have a honda xl250 4 stroke from 1974. whenever it is started it idles really high, like 5-6 thousand rpm. i am almost certain it is not anything to do with the throttle cable. would you have any other suggestions?? anything you could tell me would be a great help. thanks.
First thing I would do is turn down the idle adjustment on the carburetor. Should be a plastic thumb knob hanging off the side of the carb.
Your choke assembly could also be stuck in the on position.