A throttle cable, if not properly cared for, or if used for an extensive period of time, can eventually become frayed, worn and unusable; it is therefore important to replace this component on your dirt bike periodically. Having a reliable throttle cable is extremely important, as losing throttle control can be very dangerous, and can result in serious injury. Replacing a throttle cable takes only a few minutes of time and some basic tools.
Remove the two screws that secure the throttle housing on the right side of the handlebars. Slide the throttle housing cap up and set it aside.
Twist the hand bolt on the throttle cable counterclockwise, until it loosens up. Lift the throttle cable end up and out of the throttle housing.
Pull on the throttle cable from a spot near its connection into the carburettor, on the right side of the motorcycle's engine housing. Thread the cable down through the frame, until you have a loose cable connected to the carburettor.
Use a Phillips screwdriver to remove the two screws that secure the side of the throttle control housing on the carburettor. Pull the plate to the side to remove it. Gently slide the end of the throttle cable out.
Slide the bottom end of a new throttle cable into the throttle control housing, in the opposite way you removed the old cable.
Replace the plate cover on the control housing, using the two screws you removed previously. Tighten down the screws with a Phillips screwdriver.
Thread the new cable up through the motorcycle's frame, the opposite way you pulled it down.
Slide the end of the new cable into its connection point in the throttle housing on the bike's handlebars. Twist the hand bolt up against the housing until it feels secure.
Replace the cover on the throttle housing. Tighten down the two mounting screws, using a Phillips screwdriver.
You may have to use your throttle quick-adjust bolt after installation, in order to adjust the throttle feed to your desired tightness. To do so, just twist the quick-adjust clockwise for tightening and counterclockwise for loosening.
Always stay aware of pinch points when working around motorcycle parts.