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Fork seal change-out...did I do this right?

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Just changed the fork seals and all bushings, seals, etc with a pivot works kit on my 2007 KX250.  The manual that I downloaded seems really unclear, or maybe even incorrect, so I wanted to follow up on here about fork oil amount and bleeding vs measuring on the inner cartridge.  I found a previous thread that says ~160mL in the inner chamber, so I started with that.  The manual that I downloaded looks like below and shows that the oil level should be 123-127mm from the top of the inner tube (or 100-145mm adjustable range), but no actual oil amount.  This manual also says measure with the fork assembled but no spring.

Screen shot 2014-04-28 at 4.20.10 PM.png

 

 

Now....with this manual...the fact that it shows the spring being removed from the top of the tube makes me think this is the incorrect manual.  Also, the 2007 uses a 14mm hex head for both removing the inner cartridge and the bottom leg of the fork...not sure where the 19mm socket is from.  Doesn't this seem like the manual for a single chamber fork??

 

Preface and Questions:

 

My 2009 YZ125 manual showed the exact amount to measure into the inner fork; ie, filled, pumped the pushrod, measure with syringe to _X amount below fork tube and done.  Reassembled and added required amount to outer.

 

1)  I've read and seen where some people fill the inner fork completely full, pump the pushrod, and then bleed through the side.  Is this the correct method?  Should fork oil always be measured with the syringe for the inner cartridge?

 

2)  Does this manual look right for the newer KX250?  And what's the difference between the recommended oil level (123-127mm) and the adjustable range (100-145mm)?  If the numbers shown in the manual are in fact correct, should I be safe just pumping the push rod completely up, then measuring only the internal cartridge oil to that amount?

 

Lots of questions I know...but really appreciate the help.

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Found a few other manuals online..one dated 2004 (the one I was using) and one dated 2007 ver.7.  The 2007 ver.7 still had the older style fork diagram, what the heck!!??  Did Kawasaki not update their manual or am I just getting compiled versions?  I definitely don't want to buy one if it's still the old diagram.

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I just bought a 07 kx250 and plan on changinging the bushings and seals this week. I don't have the manual but I've been searching the net for inner and outer fork oil amounts. I found on race tech suspension site that they say 150 ml for inner. You say 160 ml .. I'm no expert but I would say I'm going to fill with 160 ml and just bleed it until it stops coming out holes. As for the outer amounts I've seen anywhere from 225 to 310.. I just read that mxa magazine claimed the best results they had were with 310 so I think I might try that. I just sent my shock off to factory connection for revalve . I'm 175 lbs (b rider) motocross only and it felt like I was just blowing through the stroke and bottoming on shock. I might call them and ask what fork oil levels they recommend.

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Correction ...I read race techs site wrong. They show 150 mm from top of chamber to oil level.. I think I'm just going to call fc and ask them the oil amounts.

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Just buy the manual it's got more info then just fork oil heights, and it's not all that much money for what it is.

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Don't worry about the inner chamber capacity.  The 160ml is a baseline for bleeding.  When you install the base valve you will have excess oil come out, should be zero air in the inner chamber, not like the outer chamber where there's a level to adjust.  

 

Dave J inner chamber assembly and free piston mod:  http://www.scribd.com/doc/121004689/KX-Free-Piston-Mod

 

You guys with the 05-07 KX250's, if you get into your forks alot, I used some (IIRC) 2" conduit U brackets to hold the inner cartridges.

 

IMG_0132.jpg

Edited by Jeekinz

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Don't worry about the inner chamber capacity.  The 160ml is a baseline for bleeding.  When you install the base valve you will have excess oil come out, should be zero air in the inner chamber, not like the outer chamber where there's a level to adjust.  

 

Dave J inner chamber assembly and free piston mod:  http://www.scribd.com/doc/121004689/KX-Free-Piston-Mod

 

You guys with the 05-07 KX250's, if you get into your forks alot, I used some (IIRC) 2" conduit U brackets to hold the inner cartridges.

 

IMG_0132.jpg

 

Thanks Jeekinz!! So, I'm pretty confused at this point.  My manual for the 09' YZ125 clearly shows to measure the amount in the inner cartridge to ~140mm below the top of the tube, but doesn't show to bleed or anything.  Should all inner cartridges be bled?

 

Also, you're saying the 160mL in the KX is a baseline for bleeding, but if you're filling up to the top and bleeding any excess, what's the point of measuring with the syringe?  Maybe I'm completely lost, but the syringe tool is supposed to be used for the inner cartridge correct?  There doesn't seem like a way to actually measure the oil added to the outer with the syringe tool.

 

Last question..it doesn't seem like I did this right and will have to disassemble to forks again.  Should I be able to reuse the seals pending everything comes apart ok?

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First off, forget the YZ manual.

 

The fork tool (syringe) is to measure the airgap in the outer chamber, spring removed.

 

I gave my shop manual away when I sold my 250, but it was something to the effect:  Damper fully (open or closed) fill with X-amount of fluid, then operate the damper rod to bleed the air bubbles, let sit for some time, I think you close the 2 holes with your fingers and add a little more fluid.  Collapse the damper rod and slowly insert the base valve (BV) into the inner chamber.  While inserting the BV, slowly pull the damper rod to seat the BV and tighten.  Operate the damper rod, hold it sideways or whatever the book says, the damper rod should push out all on it's own.  There's always like 15-20mm it won't push out though.

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First off, forget the YZ manual.

 

The fork tool (syringe) is to measure the airgap in the outer chamber, spring removed.

 

I gave my shop manual away when I sold my 250, but it was something to the effect:  Damper fully (open or closed) fill with X-amount of fluid, then operate the damper rod to bleed the air bubbles, let sit for some time, I think you close the 2 holes with your fingers and add a little more fluid.  Collapse the damper rod and slowly insert the base valve (BV) into the inner chamber.  While inserting the BV, slowly pull the damper rod to seat the BV and tighten.  Operate the damper rod, hold it sideways or whatever the book says, the damper rod should push out all on it's own.  There's always like 15-20mm it won't push out though.

 

Ok, so I clearly did this wrong on both bikes since I used the syringe to measure oil in the inner cartridge  :(  :facepalm:

 

I'll disassemble tonight and bleed the inner cartridge.  When reassembling, I'll drive the seals in and leave the inner cartridge and spring out, then compress the fork bottom until the bottom leg touches the dust seal, then use the syringe to measure.  Reinstall the spring, then inner cartridge.  **** I hate I have to take these back apart!!

 

Sounds correct right Jeekinz?  Thanks for the help man!! I would've been riding some really crappy suspension.

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Jeekinz,That's a cool idea with the fork holders! Thanks for your help with our questions!!! Ok so I've got a manual ordered but I also called Factory connection today. They told me there isn't a set amount for inner. They fill it to top,opererate the damper rod (slowly) and then repeat until oil level stays up.Next insert base valve and tighten .they also said to run 315 cc in outer tube. Hope this helps here.

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For the fork oil measurement, you just use a ratio rite.  IIRC, the adjustable oil range is 280-320ml.   The open chamber forks you use a fork oil tool.

Edited by Jeekinz

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Well I redid the YZ today, and ordered a correct service manual for the KX...hopefully.

 

Just to revisit...I left the outer/inner tubes together but drained the oil, then pulled the inner cartridge out separately.  Pulled the base valve, refilled with oil, pumped multiple times, and then allowed to sit for ~30minutes for all air bubbles to escape.  Came back, measured with syringe to ~148mm from tube top (service spec), pumped damper rod about 3/4 way up, then reinstalled base valve while pulling the damper rod down.  After base valve was back on I pumped damper rod full extension ~10 times and bleed the cartridge of excess oil.  Reassembled into inner/outer tubes.

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You guys with the 05-07 KX250's, if you get into your forks alot, I used some (IIRC) 2" conduit U brackets to hold the inner cartridges.

 

 

 

Also bought some 2" plastic U-brackets.  They were a little big, but luckily plastic bends, so I just screwed them closer together....PERFECT!!  :thumbsup:

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Good until the 148mm spec. Don't recall that.

When the inner chamber is all assembled, you just assemble the rest of the fork, right before you expand the fork to close it all up you add 280-320ml oil to the fork.

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Good until the 148mm spec. Don't recall that.

When the inner chamber is all assembled, you just assemble the rest of the fork, right before you expand the fork to close it all up you add 280-320ml oil to the fork.

 

The 148mm spec is just for the YZ, and I think that's basically just a starting point for bleeding, probably unnecessary if you can eyeball close enough to the bleed holes while filling.  At the 148mm spec, there was still quite a bit of fluid that bled out after I reinstalled the base valve, otherwise I would've been worried.

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