got the forks together... questions


Sep 11, 2006
Got the fork seals done on my friends 2002 kx125. I got the specs from the dealership that each fork should have 22oz of fork oil. I put in 12 oz and its right up to the top with the forks collapsed, springs out. So I figure pump everything and mabey some massive air bubble will come out and I'll be able to add the rest of the oil. NO dice!

So then we figure okay, mabey they ment 22oz for the whole front end. That would mean we put an extra 1oz in each side.

So on to checking the oil height. I end up sucking out 4oz from each side to get the 5.25" oil height.

Put it all together. My friend says it rides better but sits lower. And when he gets the bike off the ground the forks make a slap when they extend.

I rechecked all the schematics and know that everything is together correctly. The only thing in question is the amount of fork oil.


Dec 14, 2008
If I remeber correctly, your bike has KYB forks on it ? The proper way to measure the fork oil level is to fully collaps the fork tube, and with spring removed, measure from the top of the outer fork tube to the top of the oil. There is a level range for this, I wish I could remeber the spec. You should be able to find it online somewhere. I'm gonna guess it's around 140 mm. Just be sure to set up both forks the same.


Old MX Racer
Oct 19, 2006
You knew it was low on the fork oil, maybe. Put the forks together anyway. They set lower and clunk when extended, definitely not good! Rode it anyway?? Some one could get hurt first off. Second, you really need a shop manual, follow the steps, pour the required amount of oil in, check they are even and at the proper level. Have you ever priced any of the parts inside a set of forks$$$$.$$ Vintage Bob


Mar 16, 2005
yes, the 2002 KX125 forks have KYB single chamber forks, but they are "bladder" forks.
while non-bladder forks use a min level of 140mm, the bladder fork oil level is a tad higher, I would start at 95mm. you can go up to 70mm if I remember correctly.

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