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Fork oil volume

B

ballvo

Tricycle
Changing the fork oil on my '86 Concours and have run into an issue. Manual calls for 338ml of fork oil, which is supposed to equate to the oil 355mm down from the top of the fork tube, fully extended, spring removed. I carefully measured the 338ml and, just to confirm, I measured the depth to the oil. Turns out to be 415mm!!

I've done a bit of searching on the forum and haven't come across any threads suggesting a possible typo in the manual. I'm confident in both my measurements so my question is: Should I just increase the volume of oil to bring it up to the 355mm depth? Or drain what's in there and re-measure the volume?

Another thing I noticed, which has no bearing on the above, is that both my spring lengths are longer (531mm) than the standard spring length given in the manual (514mm). I'm a long way from being the original owner of this bike and know nothing of its previous service history. Just wondering if longer springs were a "thing" sometime in the past to address front end dive or other handling issues?

Any and all insights appreciated. Thanks.

Neil
 
Mine is a 2005 and I was confused about how to do it as well. What I found is after a curtain year the service was completely different with the tubes collapsed. I wonder if you are using the wrong method or possibly the forks are from a different year of bike???
Maybe SISF will chime in I am sure he will have an answer for you.
 
Part of the confusion is; On the early Connies; (I think) they measured the oil level with the forks extended, and with the spring "removed"...
                                    Later models were measured with the forks compressed and no spring.
                                            The later model procedure is the easiest..

On both, the EZ way to do it is: do not worry about the exact fluid volume.
                  Instead; use a distance measurement with forks compressed....
Reasoning; Distance measurement is far more precise than volume.
                Forks compressed is the easiest/most consistent way to do it..

PS: This is my "good-old-boy" method. Worked fine on all my bikes..
        This is from memory {and my memory sux}.  If I miss a step, someone can correct me.

#1)  Buy a tool that can be used to suck the oil out of the fork tubes..
          {I used a turkey baster with a rubber hose, but you can use whatever suction tool you want}.
#2) Remove the springs...
#3) Put some oil in and exercise the forks up and down to remove trapped air..
#4) Add fluid until the level {with forks compressed} is "about" 6 or less inches.
#5) Mark your suction tool at 6 1/2".
    NOTE:  {I think} Kawasaki sed 6.73" on the later models; but I preferred 6 1/2". Either will work on all.
#6) {With forks compressed & no spring); insert the tool to the depth you prefer..
#7) Suck the oil out of 1 fork tube until you suck air.
          {When you suck air, you are at your preset depth}.
#8) Suck the oil out of the other fork tube until you suck air.
#9) Extend forks.
#10) Insert springs, caps, etc.
#11) Go ride...

Your 531 mm spring dimension sounds like a spring for a later model C-10.
Whatever it is; If it has been working ok, don't worry about it. Re-use it...

Do your caps have a Schrader/air valve on the top, or a preload adjuster?
If it has an adjuster,. it is possible someone installed newer forks or fork caps on the bike..

Ride safe, Ted
 
Nah: I'm just making it up as I go along.
          I sed; "I think", "This is from memory, and "my memory sux".
          MOB knows a lot more about this than I, has better recall, and can correct it I missed anything.

Ride safe, Ted
 
Thanks Ted, much appreciated.

I had read that 6.5" measurement (with forks compressed and spring removed) elsewhere but happy to have it confirmed here.

Forks appear to be original with the air valve on one cap only.

One further question: I have a set of All-Balls tapered steering head bearings on hand and the steering stem disassembled. I've also been reading that using OEM seals and bearings is recommended over aftermarket stuff. So, kind of wondering if I should just clean and re-lube the existing steering head bearings or replace with the new All-Balls kit? (I have no way of knowing if the currently installed bearings are original or otherwise.) Thanks.

N.
 
In my opinion; This is one of those: "If it ain't broke, don't fix it moments"..

Rotate the steering head left and right while feeling for roughness.
  If it don't feel rough, I would clean and lubricate.
After you remove the bearings, feel the race's for roughness/vertical rippling.
{If it's bad the bearings will have caused rippling}.
        If it's smooth,,,  I would clean and lubricate.

The reason I say C and L is; Getting the old races out {and back in} can be a real PITA.  :mad:

Ride safe, Ted
 
connie_rider said:
Nah: I'm just making it up as I go along.
          I sed; "I think", "This is from memory, and "my memory sux".
          MOB knows a lot more about this than I, has better recall, and can correct it I missed anything.

Ride safe, Ted
Click to expand...

because of the internal fork differences in the '86-'93 models, and '94-'06 models,
PLEASE use the corresponding fluid measurement methods for the model being serviced, don't try to "adjust/re-calculate" or measure in a manner not suited to model year...


I'll stress this again, and even tho ALL C10 models have a 5.5" (140mm) front wheel travel, the internal valving, and fork volumn, (combined with the fact pre '94 models have an air crossover tube between the forks) can further be clarified as "there is a reason for the differences"... simple math will tell you the difference between an extended '86 level, and a compressed '94 level (besides the internal volumn difference) is 7-1/4". The levels and methods insure the proper levels for the operation of the internal valving.

don't bother with the "fluid liquid measurement in ml" as noted, the actual value you need to adhere to is the distance measurement from top,

Frankly, as I pretty much repeat these methods yearly, I find kawasaki's manual, and technique about the measurements a bit... ridiculous....
It would have been much simpler, and easier to relate to for anyone, if they were to just use a proper level for both different models, based on the forks extended... as that is how it's easily done... compression of the forks for the later year models, requires a tedious and painful necessity to do this all, either by 'blocking up under the front wheel, or if the wheel is off, shoving the axle in the forks, and compressing them upwards using a wratchet strap... the old bike just require letting the forks dangle free, and filling them to te dimension...(but then, the older ones actually had a drain plug/screw... what a concept..) Thanks kaw, for making it time consuming... :-[ :-[ :-[ :-X :-X ::) and harder than it needed to be.

SOOOOO.... TED.....
next fork oil change, do it exactly like the book says, and then let the forks dangle... and give us the 'secret dimension' for '94 and up with the forks dangling... THAT would be a NICE number to have. :) :rotflmao: :rotflmao: :nananana: :nananana: :nananana: >:D >:D

pre '94 ('93 DOWN TO '86) IS DONE SPRINGS OUT, FORKS FULLY EXTENDED...
'94 AND UP, IS DONE SPRINGS OUT, FORKS FULLY COMPRESSED

FLUID LEVEL FROM TOP OF TUBE IS;
PRE '94    355MM (13.98", 14" EXACTLY IS OK, BUT NO MORE)
'94 AND UP    171MM (6.73", 6-3/4" IS ok BUT NO LESS)

FREE SPRING LENGTHS ARE;
PRE '94  NORMAL-514MM (20.24")... REPLACE IF AT OR LESS THAN 504MM (19.84")
'94 AND UP  NORMAL - 543.3MM (21.38") REPLACE IF AT OR LESS THAN 533MM (20.98")

you may have a set of aftermarket "Progressive" springs installed, they are slightly longer than stock ones, (Which will coorelate the dimensional difference you found, as "longer than an '86-'93, and shorter than a '94 up dimension)  and when installed, the 'tubular' top spacer is not used ( was there a tubular spacer installed above the spring????)
(the hat shaped washer is tho, sits on the spring), so the longer spring may be a Progressive. (they are long enough that it requires you to press down hard on the cap during it's install, but just don't try to use that extra tube, along with the Progressive springs, ).
I've installed Progressive's in both my C10's, and they are a step up in suspension, not the big buck thing like some will argue, about custom springs, and emulator cartridges, and such, but still good springs, and an improvement over stock/
the picture is from Murph's site, and I can't say for certain it is showing the comparison between stock and Progressive, maybe it is, but I'm not saying that...
I do know the Progressives did have 'more windings' and were longer, and all my old springs are in a box in my garage crawlspace... so i'm not diggin them out for pictures...
anyway, here...
concours%20progressive%20springs.jpg

hope this helps... oh, if you are doing this on a pre '94, with air assist forks, you no longer need 'air' assist when Progressive springs are installed... this upgrade (springs) helps give longevity to the fork seals, as they no longer have to seal 7 psi of air pressure in the forks (which was the 'max' air pressure noted for use).

so, look closely, and verify you are actually working on '86 forks, (with air cap on one fork, and an '86-'93 front wheel) (and that a complete fork/wheel assembly has not been retrofitted from a '94 up bike ; '94 up uses a different front wheel, easy to spot)
and finish accordingly.
best of luck, use the method for the bike being serviced, and all will go well...
 
MAN OF BLUES said:
don't bother with the "fluid liquid measurement in ml" as noted, the actual value you need to adhere to is the distance measurement from top,

pre '94 ('93 DOWN TO '86) IS DONE SPRINGS OUT, FORKS FULLY EXTENDED...

FLUID LEVEL FROM TOP OF TUBE IS;
PRE '94    355MM (13.98", 14" EXACTLY IS OK, BUT NO MORE)
Click to expand...

Thanks, this is what I wanted to know.

Definitely '86 forks and wheel.  No tubular spacer so may be Progressive springs - the length does require a lot of pressure to get those first threads on the cap to 'bite' . Thanks for the tip re: no air assist necessary with these.
 
ballvo said:
MAN OF BLUES said:
don't bother with the "fluid liquid measurement in ml" as noted, the actual value you need to adhere to is the distance measurement from top,

pre '94 ('93 DOWN TO '86) IS DONE SPRINGS OUT, FORKS FULLY EXTENDED...

FLUID LEVEL FROM TOP OF TUBE IS;
PRE '94    355MM (13.98", 14" EXACTLY IS OK, BUT NO MORE)
Click to expand...

Thanks, this is what I wanted to know.

Definitely '86 forks and wheel.  No tubular spacer so may be Progressive springs - the length does require a lot of pressure to get those first threads on the cap to 'bite' . Thanks for the tip re: no air assist necessary with these.
Click to expand...

yep, the 'no tubular spacer' is the giveaway. Progressive's for sure...
handy hint for gettin the caps back on...
before installing the springs, get a marker, and install a cap, thurn it one full turn. mak a mark on the edge of the cap where you can see it, then, while gently pulling up on the cap, loosen it till it 'pops free, make a coresponding mark on the fork tube... do the same with th other tube and cap, and keep them segregated by side... when you stick the springs in, and that washer on top, set the cap on, and press down with the appropriate hex socket on the end of a 'speedwrench', (see photo below) aligning the marks, and press and turn... easy peasy.. no stripped threads, and makes it all a painless thing with no worry.
 

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See, I told ya'll he knew more than me.  :great:

As it happens; I recently removed the Progressive Brand Springs from my 03 while I was trying to set spring sag.
My Progressives measure 20 3/4" {this is 5/8" below the 03 specified length and 1/4" below the min.}
NOTE: These springs "are" used so they do have some sag, but I doubt they have sagged that much  {???}

My guess is balvo's springs will be about the same length.

Since my dirt bike days, I've always done mine with forks compressed as it's just easier for me to do it this way.
  The way I understand it; measurements were done with the forks compressed because that way was considered more accurate.
  ie; The dangling "wheel/forks/brakes/etc weight" is partially compressing the Topping Spring.             
        Supposedly that spring compression makes the measurement less precise.?.?

We'll both agree that the difference between both methods is just splitting hairs.
Most could not tell any difference from that little difference in fluid level..
So, I agree;  "Either way will work". 

Ride safe, Ted

PS: Both the Progressives and the stockers sag to much. {to set the sag as recommended in YouTube video's.. {???}}
      So, I'm getting ready to remove about 4" from these to stiffen the front end a bit..
          (In one of his posts, Bubba sed he removed about 6" from his springs, so I think 4" will be ok?)
          Any thoughts on how much to cut?
 
:mad:

the O/P is working on an '86...

you are putting words in my mouth I did not say...
and I don't agree on all the points you have eluded to below..

connie_rider said:
See, I told ya'll he knew more than me.  :great:

As it happens; I recently removed the Progressive Brand Springs from my 03 while I was trying to set spring sag.
My Progressives measure 20 3/4" {this is 5/8" below the 03 specified length and 1/4" below the min.}

BUT THEY ARE STILL LONGER THAN THE NORMAL '86 SPRINGS...
MY MOB COMMENT
NOTE: These springs "are" used so they do have some sag, but I doubt they have sagged that much  {???}

My guess is balvo's springs will be about the same length.

Since my dirt bike days, I've always done mine with forks compressed as it's just easier for me to do it this way.
  The way I understand it; measurements were done with the forks compressed because that way was considered more accurate.
ie; The dangling "wheel/forks/brakes/etc weight" is partially compressing the Topping Spring.             
        Supposedly that spring compression makes the measurement less precise.?.?


BY WHO'S OPINIONS?
MY MOB COMMENT

We'll both agree that the difference between both methods is just splitting hairs.
Most could not tell any difference from that little difference in fluid level..
So, I agree;  "Either way will work". 


I NEVER SAID THAT WHATSOEVER, AND DO NOT AGREE...
MY MOB COMMENT
Ride safe, Ted

PS: Both the Progressives and the stockers sag to much. {to set the sag as recommended in YouTube video's.. {???}}
      So, I'm getting ready to remove about 4" from these to stiffen the front end a bit..
          (In one of his posts, Bubba sed he removed about 6" from his springs, so I think 4" will be ok?)
          Any thoughts on how much to cut?
Click to expand...

sorry, I'm not getting the 'topping spring' thing you elude to... the bottom damper rod is bolted to the bottom fork tube...
I'm saying there are internal volume differences in the fork tubes between the old and newer models... there are also differences in the valve damping and hole locations in the damper...
but, here is the part you are not listening to me about....
the air balancing crossover tube, on pre 94 models.... lives right above the lower triple tree.... right about 9" from the top of the fork tube.....

this air balancing crossover sits well above the normal pre '94 oil level.... it has to...  are you getting what I'm selling yet? :rotflmao: :nananana:

so telling him to compress forks, and fill to 6"+whatever from the top.... ?
maybe the fluid will drop and equalize evenly when extended, but likely not.. THAT is why the procedure for pre '94 bikes is as it is... and should be followed. ::) :-[

I luv ya bro, truley do, but unless you do a fill on your post '94 bike, compressed, and then tell us the measurement when they are extended... and it's 'close' (like in tossing hand grenades close) there can be no assumption made. OR even the O/P, with his '86, can fill per the book, and then compress the forks and measure what he has (and making sure both forks remain equal during the process), and then return them to extended, and re-measure to insure they are still equal.
THEN, we can have a firm dimensional figure...somewhat... :rotflmao: :rotflmao: :rotflmao:

How many seals have we gone over here, and on the other site, because people over filled?? many.
:truce: :truce: :truce: :truce:

as for Progressive springs on post '94 bikes, yes, I have heard many say they still are mushy, and sag... but on pre '94 bikes, like the O/P has, and I have and had, they do improve over the OEM system. :great: :nananana:
 
I will correct my previous statement; I sed we both agree that both methods will work.
    You disagree.
        So, let's agree that we disagree...

Replies to your questions/statements.
1) I already "did" what your suggesting. I developed the 6 1/2" dimension on my 86.
    **ie; I serviced the 86 fork {extended}, then compressed the fork and remeasured the fluid level.
          As I recall: It was closer to 6 3/4" but I prefer less dive when I brake, so I raised it an extra 1/4". {became 6 1/2"}
      I AGREEE, the OP can repeat my test.
2) I also agree that the Progressives are longer than the 87 original springs.
      I just pointed out that these are shorter than my stock 03 springs are supposed to be.
3) The topping (rebound) spring is the spring that is installed on the damper rod before you install the damper rod into the upper fork tube. (You can see it in the C-10 service manual ({page 12-2} {exploded view/below the damper rod})
            This spring prevents the forks from banging when the forks "top" out.
  https://www.ebay.com/itm/1986-KAWASAKI-GTR1000-ZG1000-CONCOURS-FRONT-FORK-DAMPNER-DAMPER-TUBE/263606166892?hash=item3d6026e56c:g:ho8AAOSwz9la0R~X
        After installing the damper rod into the upper tube a tapered bushing is installed on the base of the damper rod.
        Next this "assembly" is installed into the lower tube. At that time, (I agree) it is bolted to the bottom fork tube...

4) Not sure why you concerned with the oil level being above the air balance tube?
      Why is that a concern? The fluid level "routinely" moves above the air balancing tube. (see below)
          ie; {extended} Fork is filled to 14" from the top.  /  Air balancing "cross over tube" is 9" from the top.
                Result; Fluid is 5" below the crossover tube..
              Replicate a nose dive by Compressing the forks 5 1/2".
                    In this case, fluid would be 1/2" above the crossover tube.
              NOTE: As the upper tube moves into the lower tube {5 1/2"}, the fluid is displaced by the upper tube .
                      **Because of the displacement, the fluid level will increase a greater rate than the fork movement.
                          I maintain that the 5 1/2" or tube movement {and the displacement} would cause the fluid level to rise to 7 1/2".
                              (ie; That 7 1/2" would make the fluid level 6 1/2" below the top when forks are compressed...)                   
                When the fork spring is installed (it also displaces fluid and raises the fluid level)
                      With everything included; The fluid level (that was originally set at 14") would now be well above the
                        crossover tube.
                (fully assembled, I suspect the only time the balance tube is below the fluid level is at or near full extension).

                  Hard to type out what I'm thinking.  Hope my explanation makes sense?                         

Ride safe, Ted 

Everyone please notice that this is 2 adults discussing differing opinions...
              We're not arguing and fighting. "we're discussing ".. 

PS: I still think I'm right...  :nananana: :rotflmao: :nananana: :rotflmao: 
 
this air balancing crossover sits well above the normal pre '94 oil level.... it has to...

I'm still pondering why you think this is a problem?

What I think is: {when the fluid level is above the air balance tube holes} your concerned that the fluid level will migrate from 1 fork tube to the other? 
{Making the fluid level higher in 1 tube than the other?}
    I completely agree that fluid can/will migrate thru the air balance tube when this occurs..

But; The air balance tube has 2 purposes.
1) Equalizes pressure between the 2 fork tubes.
2) Equalizes fluid level between the 2 tubes.

ie; The air balance tube is more than a way to balance pressure. It is also a crossover tube for the fluid.
      So the fluid will migrate from the higher side to the lower until it is level...
        ie; Fluid will seek a level whenever there is a fluid connection between the 2 tubes.

NOTE: If I am incorrect and the fluid level is always below the holes for the air balance tube,  you would be correct.
          But, here we disagree.....
          As I tried to show earlier, the fluid level is routinely "above" the holes for the air balance tube.
                At that time, the fluid has to self level.

Agree or disagree?

Ride safe, Ted
 
I think the easiest way to stop confusion is:
He (balvo) should service his forks to 14" with the forks extended as MOB sez.

Use my previous steps to fill the forks, but do the fill and measurements with forks extended.

After filling, please compress the front suspension and measure the fluid level.

If it is not 6 3/4" my memory was incorrect.
 
connie_rider said:
Just to stir this up a bit... <evil grin>
Race Tech says the oil level on "all" the C-10 forks should be 150 mm (5.9").

Ride safe, Ted
Click to expand...
Collapsed, extended, spring in or out???? :nananana:
 
Yes, compressed, spring out, and emulator in..
    This is quite a surprise as Kawasaki recommends 170 mm / 6.73" on the later models..
    I've been stating that 6 1/2" was ok on all the models, but their saying 150 mm / 5.9" on all models...
        That is quite a step...

Ride safe, Ted
 
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