Adjusting the Fork Height on a KX125

The Kawasaki KX 125 dirt bike is suitable for riders who want an entry-level bike. As with all bikes, it can be modified and fine-tuned to suit your specific riding style. It is easy to adjust things such as the seat height, but it is more complicated to adjust the fork height. The fork height is dependent on a bladder system that is filled with oil. The height can be adjusted depending on the amount of oil within the fork leg. You will need some special tools to do this modification.


1) Remove the fork top plug from the frame by unscrewing the bolts with a wrench on the top and bottom of the fork. Pull the fork out of the wheel assembly after it has been unscrewed. The fork is the piece of metal that holds the front wheel of the bike in place.

2) Secure the fork vertically using clamps or a vice.

3) Remove the top plug from the outside tube by rotating the cap counterclockwise with a wrench until it is no longer connected to the outside tube.

4) Compress the outside tube by pressing it down while it is in the vice and press the fork spring away from the top plug. You can do this with your hands or a flat-head screwdriver if the spring won’t come loose. The fork spring is actually two long springs that sit inside the metal tubing on the fork.

5) Slide the fork spring holder away from the top plug and the push rod nut to allow you to reach the nut. The fork spring holder is a C-shaped clamp. The top plug is the plug at the top of the fork, and the push rod nut is a medium-size nut that holds it all in place.

6) Loosen the rod nut with a wrench, and remove the top plug by pulling it off the assembly.

7) Remove the fork spring holder and lift the fork spring out of the inside tube. You can do this now because the top plug is now completely apart from the assembly.

8) Empty the oil from the now-opened fork tube into a container.

9) Vice the fork leg vertically so that it is fully compressed.

10) Fill the fork leg with oil based on your desired height. You can adjust the oil height between 75 and 115mm.

11) Attach the fork piston rod puller onto the fork leg. It will snap into place once it has slid into the inside tube. Push it up and down a few times to expel any air from the cylinder. Let it sit for a few minutes so any air bubbles will rise to the top.

12) Reassemble your fork by following these steps in reverse.

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