Fork oil change, how much oil?

I am going to change my fork oil. How much oil do I need to buy? I weigh 250lbs. ( remember muscle weighs more than fat! ) and have stiffer springs in the forks but they are still soft when jumping. What weight oil should I use. The manual has a min. oil height, what is the max height I can go.

The range is 80-150mm. Start around 100 and add as required. You could try a 7 or 10 weight cartridge oil.

How much oil will I need to buy?

I BELIEVE 500cc's per leg put my 99 @ minimum level (whatever the capacity is of a RATIO RIGHT). I used PJ1 2.5 weight, and I need to raise my level (I weigh 170#).

According to MXA, 5 wt should be the minimum viscosity to ensure proper lubrication of the fork internals. Kayaba 01 IS 5 wt.


'99 WZ/YR (you choose!) with ALL YZ mods, de-octopused, DSP Doug Henry airbox w/ velocity stack, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, OEM YZ tank, IMS YZ seat.

I changed the oil last night. I followed the directions to the letter. It took less than 1qt. for both forks w/a height of 90mm. Does that sound right. Seems like it should have held more than that.


Priming the cartridge with oil is critical for attaining the proper oil height. I tore my forks apart and thoroughly cleaned them prior to adding oil. If you did not fully dissasemble your forks, then yes, you may bo OK on oil level...

No I didn't disassemble them but I did pump the tubes to get as much of the old oil out as possible. I filled the tubes, pulled the dampener rod up and down a dozen times, and extended the outer tube all the way up and put it back down. I then pumped the outer tube about 7" several times to get the air out. I pushed the the dampener rod all the way down and then set my oil level at 90mm w/my turkey baster.

Hey Finglan,

That muscle you speak of that weighs so much? Would that be the hangous overthebeltous? Sorry man I just couldn't resist. :D You just opened yourself up for that one! I hope you forget this shot by the time we get together again, (that may be a while now)! Serously if it wasn't for the big guy I would still be stuck in a rock field somewhere in the Aleghenny National Forest. Thanks for bailing me out of that one. :)



'00 WR 400

Western Fab Insert, YZ timed, airbox lid removed, YZ throttle stop, Michelin S12's, UFO YZ plastic,Mobile 1.


You forget I have the added weight of a full head of hair! Give me a buzz if you want to ride in Swain. They have been going down about every Sunday now to get ready for the Sept. 9th race. It is a 5 mile loop much tighter than Allegheny, hence slower. Lots of smaller rocks but less roots. Good place to get used to the rocks. I finally put new meat on the rims.

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