Fork oil fill level confusion
  • billygoatgruff
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    Fork oil fill level confusion

    by billygoatgruff » Fri May 31, 2013 3:35 pm

    Hey Guy's I'm fixin do replace my fork seals on my 250x. I've read how too's and watched videos of how to do it and it looks pretty straight forward. My question or my confusion is how much oil to put back in? I want to replace the oil in the inner cartridge at the same time. My owners manual says that there will be X amount of oil left in the damper if you let it drain for X amount of time. If I completely disassemble the fork wouldn't there not be any oil remaining? Manual says with standard spring and standard capacity requires 11.8 oz of oil and the only thing I can find on the inner damper is 6.5oz
    Am I over thinking this? Should I just disassemble and put in the 6.5oz in the inner damper and then put 11.8oz in the outer and call it good?

    Thanks BGG
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    JimDirt
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    by JimDirt » Fri May 31, 2013 5:21 pm

    The inner chamber is just filled so it is past the lip that is down inside , i usually fill about a inch over , then as you slowly push the cartridge in , it will push out the excess (you have to put a fair amount of pressure till its in far enough to thread on), all the excess oil is not used , then as far as the outer chamber goes , what i do (since its completely disassembled) , is take the Blue Scott towels (the ones you get at Wal-Mart in the Auto section) , and a broom handle , then put a couple of them over the handle , and push it thru , this will remove any leftover fluid

    The reason behind this is a few ounces of fluid can make a difference from side to side , so to avoid any extra fluid being in the parts (i do this with the lower tubes as well) they want you to let the parts sit for X amount of time to completely drain , so it wont be unbalanced from side to side and so when you put in 365cc that is what you are putting in , so as long as you wipe/blow them out good , you should be able to assemble everything quickly and not have to wait
  • billygoatgruff
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    by billygoatgruff » Sun Jun 09, 2013 6:52 pm

    Ok, I did my seals and also did a complete fork oil change. I found a good youtube video that walked thru the process on a Honda fork.
    So now that it's all done I noticed a difference in the static height of the front of the bike.(static meaning bike sitting under it's own weight. I think that's the correct term)I have a custom fork brace that I made out of a block of wood. Before the change i could put the brace in with no problems. Now that I changed the fork oil I have to lift the front slightly to get it in. About an inch. I followed my owners manual for the amount of oil. It says 11.8 oz for standard with 13.5 oz. max. I put in 12. Could I have not put in enough oil? I don't have a service manual that shows the amount for a complete fluid change.
    Just the owners manual. Anybody have a service manual that states the correct amount at a complete change??

    JimDirt, I did follow your instructions on how to completely remove all of the old excess oil

    Thanks, BGG
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    riddler9
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    by riddler9 » Sun Jun 09, 2013 7:20 pm

    Did you check to make sure the cartridge decompressed properly after reassembling it? It is pretty easy to trap air that pushes out oil so you end up with too little oil in the cartridge. Sometimes the cartridge ends up creating a vacuum that pulls the rod back in as well.

    It is likely not a problem with the oil in the outer tube as the amounts you are talking about are correct.
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  • billygoatgruff
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    by billygoatgruff » Sun Jun 09, 2013 8:22 pm

    riddler, I'm pretty sure that they got bled correctly. Once i filled the cartridge I compressed the dampnig rod up and down slowly a couple of times to get the air out.

    BGG
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    JimDirt
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    by JimDirt » Mon Jun 10, 2013 8:12 am

    When you compressed the cartridge by hand , did it extend fully on its own ?? , if it did not , that would explain the fork sagging too much , which would mean you need to re-bleed the cartridge , if anything with all fresh fluid the bike should be slightly stiffer and hold up higher , not lower

    If your Owners Manual shows the fork rebuild process , it should be giving all the info for oil capacity
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  • billygoatgruff
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    by billygoatgruff » Mon Jun 10, 2013 10:22 am

    Yes the damper rod extended back out fully on it's own. I think I'm goin to get another qt of fork oil and go thru and bleed them again just to be sure. I road the bike and they seem to be working fine. Just the static load is lower now for some reason. After doing it once , it's pretty easy. The fork is not as complex as I'd thought. I did not get into the damper part of it. I'm sure that's a little different.
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    JimDirt
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    by JimDirt » Mon Jun 10, 2013 5:48 pm

    Just as a question....How much do you weigh ??? , a 250X will only support a 150-165 lbs rider max without stiffer springs , a 450X will support a 180 lbs rider max without stiffer springs , if your setting your sag and you weigh too much for the stock springs it will throw your static sag off because you are trying to compensate for not having the correct rate spring when setting the sag , so its stiffening up the rear spring which is holding the rear up higher and adding more weight to the front end (just sitting there)by the rear being higher it throws the balance weight of the bike forward more resulting in more sag in front
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    riddler9
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    by riddler9 » Mon Jun 10, 2013 8:08 pm

    billygoatgruff wrote:riddler, I'm pretty sure that they got bled correctly. Once i filled the cartridge I compressed the dampnig rod up and down slowly a couple of times to get the air out.

    BGG


    When bleeding the cartridge, hold it at a 10 degree tilt for the majority of the process instead of vertical. It yields much better results.
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  • billygoatgruff
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    by billygoatgruff » Thu Jun 13, 2013 8:09 pm

    JimDirt wrote:Just as a question....How much do you weigh ??? , a 250X will only support a 150-165 lbs rider max without stiffer springs , a 450X will support a 180 lbs rider max without stiffer springs , if your setting your sag and you weigh too much for the stock springs it will throw your static sag off because you are trying to compensate for not having the correct rate spring when setting the sag


    I haven't made any adjustments to the sag. The sag is with in spec. The only thing that has been changed is the fork oil, and that somehow changed the static height of the forks.
    I'm going to disassemble them and re-fill and bleed them again and put the same amount of fork oil back in and see what that does? If it doesn't change the static height I'm just going to add a couple ounces one ounce at a time until I either hit the max fluid level or get the static height I had previously.

    It might be awhile before I can get back to the bike or the thread. I just had to evacuate from the Black Forest fire here in CO. I evaced my Mom on Tuesday and she was staying with us then we got the evac order yesterday. She's with my sister and we're with some friends.

    Stressing!

    BGG
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    JimDirt
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    by JimDirt » Thu Jun 13, 2013 8:47 pm

    OK your static and race sag are both in spec correct ?? , they must ALL be correct including free sag , usually OEM puts the oil level at Standard , so that amount SHOULD be sufficient to hold the bike up provided you are within the rider weight specs for standard springs , so it might be a good idea to re-check the procedure you did , since usually you would have LESS front sag then you had before after a inner and outer oil change , and the only need to adjust the oil level is for "feel" preference and bottoming resistance , not to make the bike hold up where it should

    And good luck with the fires , hope everyone remains safe !
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