Here’s a DIY guide for rebuilding the 43mm inverted Kayaba forks on Kawasaki KLX 250
Oil Seal, Dust Seal, Bushing, Inner Bushing Piston-Fork, Snap Ring, and 600ml of fork oil:
Note that the inner fork tube has some sharp edges:
It’s a good idea to wrap those edges (I like electrical tape while the service manual says to put a bag over the end) to avoid damaging the oil seal and dust seal when you slide them onto the tube.
Next slide on the new parts in the order shown:
At this point you are supposed to use a special oil seal driver tool to seat the bushing and oil seal. Since I don’t have that tool I made one from the old oil seal:
Cut a section out of the old oil seal so that you can slide it onto the fork tube. Make sure you round the edges as you don’t want to scratch your fork tube. Finished product- a home made oil seal driver:
Now we are ready to seat the bushing and oil seal-
Slide your DIY oil seal driver onto the fork tube like this:
And use it to seat the bushing and new oil seal:
Once the new oil seal is fully seated, remove your homemade seal driver tool and install the snap ring-
Then push the dust seal into the outer tube like this:
Now we are ready to add new fork oil. Depending on how much oil you managed to drain from the fork you will need to add between ~450-530ml of fork oil.
The service manual calls for using a “Fork Piston Rod Puller” special tool to move the piston rod up and down a dozen times or so to get rid of all the air in the fork, but I find that the top plug works just fine for that purpose:
The oil level in this fork is supposed to be about 10cm from the top of the inner fork tube. Again, Kawasaki recommends a special tool, but I just made a “dipstick” and slowly add oil until I’ve reached 10cm from the top of the inner fork tube:
If you accidentally overfill the fork you’ll need to use a syringe and tubing to suck out the excess oil.
Once you’ve got the appropriate amount of oil in the fork it’s time to reinstall the fork spring:
Kawasaki calls for a special “fork spring holder” tool to hold the spring below the piston rod nut, but I find it’s not hard to get a 17mm spanner on the piston rod nut. You will want to torque the piston rod nut against the top plug to 11 ft-lbs:
Last step- pull up the outer fork tube and install the top plug, torque to 22ft-lbs. (Easiest way to torque this is to install the fork back into the triple clamp, then tighten).
Let the Good Times ROLL!