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Discussion Starter · #1 · (Edited)
HOWTO: ZX6R G1 Front fork refurbishment

Having spent some head scratching and loads of "Googling" to find the answers to removing the fork internals, I thought I'd share what I learnt for those attempting the same.

Please bear in mind that I'm not a mechanic by trade so some of the terminology used may not be correct but the process is correct as I've done it on my bike !




Front fork refurbishment 1998 ZX6R G1

Removal:

*** In the age of modern camera phones, it is a good idea to photgraph everything before you remove / loosen it - it helps when reassembling !! ***

1) Use slings to lift and brace the front of the bike - remove the front wheel.

2) Back off the rebound and compression screws to fully out (Make sure you remember / make note of how many clicks / turns it took)

3) Before removing the forks, loosen the allen bolt that can be accessed from the cavity that normally holds the front axel. It's an allen bolt so TAKE CARE not to round it off !!!

4) Loosen, but do not undo the top fork cap (blue in my pictures on my bike) whilst the stanchion is still gripped by the bike. Use the spanner supplied with your bike.

5) Remove the forks from the bike (take photo / remember how far above the billet the botton of the fork caps sit - in case you've dropped the forks through the head for different geometry)

6) Now remove the (blue) fork cap - this screws into the stanchion so be careful not to damage the stanchion (unless of course its being replaced). Don't worry about parts pinging all over your garage - although this is under a little tension with the spring it is minor and can easily be contained with your hand.

7) Pour the old fork oil out into a container and tip it over your neighbours wall - if you like your neighbour, send it to me and I'll tip it over mine cos he's a dork.

8) With a spanner on the nut of the fork internals, you should now be able to remove the compression / preload cylinder (silver, at the top of the fork internals, just under the blue cap) with another spanner.

9) You should now be able to remove the washer, spacer, washer and spring and internal piston rod.

10) Remove the dust cap from the outside of the stanchion, and the retaining clip that holds the fork seal in.

11) Now the fun bit !!! The next step to remove the internals requires a special Kawasaki tool, or in my case a pice of "flat-bar", approx 1 metre long tapered to provide the required size of "screwdriver head". I have also read of a shower-curtain pole being reformed to create a "square end" in place of an expensive Kawasaki tool.

Look into the fork and you will see the rod protruding through the internal cartridge. You will need to brace the cartridge to prevent it spinning so you can remove the allen bolt from the botton of the fork.

I achieved this (not recommended) by jamming my flat-bar down inside between the rod and the cartridge. Once you can prevent the cartridge from moving the allen bolt should come out with ease.

12) Now the allen bolt from the fork base has been removed, sharp tugs (a-la a slidehammer) on the stanchion tube should pull the stanchion tube (with oil seal and bushings attached) from the fork base.


Refitting:

1) Give everything a good clean-up removing any traces of old oil / cabbages from inside the fork body and all removed parts.

2) Inspect the stanchions for pitting, the bushings for wear and any other inspections that may be needed - now would be a good time to replace anything if necessary !

3) Lubricate the new oil seals lightly on their insides so they go on the stanchion a bit easier, and refit in the correct order with the bushings (told you photos would help !!)

4) Reinsert the stanchions with bushings and seals attached into the fork base, carefully ensuring the lower circlip is correctly seated.

5) Reinsert the reassembled internals carefully inside, then nip up the allen bolt into the bottom of the cartridge.

6) With everything in place now tighten the cartridge to the fork base using your newly aquired expensive Kawasaki special tool.

7) Now seat the fork seal correctly using a fork seal punch, piece of scaffold tube, or in my case using a punch and rubber hammer to carefully reseat the fork seal - take care and take your time at this stage as it is REALLY EASY to damage the seal.

8) Replace the fork seal retaining clip.

9) Brace the fork vertically in a vice (or get a mate to hold it) and refill the fork oil.

For my model: 588ml +/- 4 ml (less in earlier models I believe but check with a workshop manual). I used 3 x 0.5L bottles, so I could easily pour the first 500ml in, then used a horse syringe (50ml) to do the topping up to 590ml - my eyesight is too poor at this age to get exactly 588!! Ensure you get EXACTLY the same in each fork !

10) Now slide the dust cap over the stanchion and replace the piston rod, spring, washer, spacer, washer in the correct order on the inside.

11) It's a bit fiddly, but now reattach the compression / preload cylinder (the silver bit) to the correct height onto the internal cartridge.

12) Slide the stanchion up to meet the fork cap (blue) and nip up as much as you can by hand. Seat the dust cap correctly, if not already done.

13) Clamp the fork back onto the bike to be able to tighten the blue fork cap.

14) Readjust compression / preload and rebound damping as required.

15) Do the other fork !!


I apologise now if there are any errors in the process (I hope not !) and wish you luck with yours !

Regards,
Warrington.
 

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good write up.... many thanks.

my forks are in need of fork seals and oil in the very near future.
 

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Discussion Starter · #3 ·
You're welcome.

It seemed a daunting task before I got started but once you're in, it's all pretty straight forward.

Good luck with yours - the best approx. 50 quid I spent and it saved me a fortune of getting someone else to do them.

WM
 

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where abouts in Scotland are you?

i lived in Perth for a number of years
 

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I have a 2001, and the seals/oil have never been replaced. I'll be doing a fork oil change in the the next couple of weeks, or at the end of the season.

The suspension is in good shape. The bike hasn't been stood up hundreds of times either. Is this a "while you are in there" job to replace the fork seals?

Not gonna lie, The fork seals look slightly intimidating. I know I could do the oil no problem. If mine arent leaking, and the front end has been bounced off the pavement a million times, not sure its entirely necessary to replace them.

I wanted to get your guys opinion. For someone that has never done fork seals or fork oil before, I'm not sure I wanna take up an entire sunday working on my suspension
 

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Discussion Starter · #7 · (Edited)
Paintpollz,

Just to be clear I am no mechanic - I am simply an owner who is too tight to pay someone else to do something I was sure I could do myself. I HAD to replace my seals as they were "misting" on the stanchion and failed the MOT (annual roadworthy check in the UK) and had never done anything like it before.

I too was a little intimidated by the process but having now done it the ONLY difficult part of the process was preventing the inner cartridge from spinning (step 11 "removal" and step 6 "refitting" above). I have read of a number of novel ways to achieve this with homemade tools to avoid paying for the expensive special Kawasaki tool. Once I had ground down a piece of flat bar (approx. 1m long) to make a "screwdriver-like-head" that fit, the job was a doddle. The seals were one of the easier bits to the job, just take care when fitting the new ones and you'll be fine.

My opinion would be having got that far, for the sake of a few extra dollars you'll then KNOW that your seals are good - it would be a shame if 6 months after you'd changed the oil, the seals started leaking !

If you were my mate down the road I'd be saying "go for it" and do the seals as well, but I can well understand your reticence.

For reference I took approx. 4 ~ 5 hours for the job, BUT I was doing it blind and learning as I went. I was double checking on the internet as much as I could at each stage to ensure I didn't make any stupid errors, so I'm sure with the instructions and some enthusiasm you could almost certainly halve that time. I did have the luxury of a mates garage and scissor ramp where it could stay overnight, so I had no time pressures to "get the job done by".



If you do decide to dismantle the forks, it would be of a real benefit to other owners if you could measure the size of the square recess in the fork internals where the "special tool" needs to go (from memory I'd say it was approx. 13mm or 1/2 inch along each side of the square).

All the best and good luck with the job - I'd be grateful to know if the steps above help.

For others reading these posts, once the rest of the parts turn up (hopefully this morning) and the bike's back together and on the road, I shall be posting on setting up the suspension. Stay tuned viewers !

Safe riding,
Warrington
 

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Paintpollz,

Just to be clear I am no mechanic - I am simply an owner who is too tight to pay someone else to do something I was sure I could do myself. I HAD to replace my seals as they were "misting" on the stanchion and failed the MOT (annual roadworthy check in the UK) and had never done anything like it before.

I too was a little intimidated by the process but having now done it the ONLY difficult part of the process was preventing the inner cartridge from spinning (step 11 "removal" and step 6 "refitting" above). I have read of a number of novel ways to achieve this with homemade tools to avoid paying for the expensive special Kawasaki tool. Once I had ground down a piece of flat bar (approx. 1m long) to make a "screwdriver-like-head" that fit, the job was a doddle. The seals were one of the easier bits to the job, just take care when fitting the new ones and you'll be fine.

My opinion would be having got that far, for the sake of a few extra dollars you'll then KNOW that your seals are good - it would be a shame if 6 months after you'd changed the oil, the seals started leaking !

If you were my mate down the road I'd be saying "go for it" and do the seals as well, but I can well understand your reticence.

For reference I took approx. 4 ~ 5 hours for the job, BUT I was doing it blind and learning as I went. I was double checking on the internet as much as I could at each stage to ensure I didn't make any stupid errors, so I'm sure with the instructions and some enthusiasm you could almost certainly halve that time. I did have the luxury of a mates garage and scissor ramp where it could stay overnight, so I had no time pressures to "get the job done by".



If you do decide to dismantle the forks, it would be of a real benefit to other owners if you could measure the size of the square recess in the fork internals where the "special tool" needs to go (from memory I'd say it was approx. 13mm or 1/2 inch along each side of the square).

All the best and good luck with the job - I'd be grateful to know if the steps above help.

For others reading these posts, once the rest of the parts turn up (hopefully this morning) and the bike's back together and on the road, I shall be posting on setting up the suspension. Stay tuned viewers !

Safe riding,
Warrington

Warrington,

Thanks for your advice, it's extremely helpful. I'm glad you are in the same boat as I am. I can use my mothers garage to perform the work, so I don't have deadlines as well. I think I will end up doing this at the end of the summer, unless I find a saturday morning or a day off with extra time. Summer plans fill up quick.

Thanks again, I will certainly measure the square recess.
 

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Hi,

+1

thanks for the writeup!

I googled some threads already about messed up front fork compression damping adjuster screws... The problem is the left one on my ZX-6R G1 is stuck...

I rather wanna send the fork in and have it refurbished ... and get harder springs... and maybe pop this in :

http://www.k-tech.uk.com/product_detail.php?id=1057

but about the original ones... i just see this screw head where you can adjust the compression (click) and nothing else how will they come out ?

oh yeah and im searching for a workshop for the refurb job in... Budapest :squint - posted that on a local forum aswell... but anyway if you are living in Hungary too feel free to post...

until that ill try my luck with WD40...
 

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Discussion Starter · #11 ·
Tornado,

As I said in my first post I'm not a mechanic, just a practically minded bike owner.

The link you sent for the replacement part looks different from the one I took off - although the link states its for a 1998 ZX6R, maybe the compression adjuster is for a set of USD forks (I'm sure later models of the ZXR went to USD forks) ? I can't see how this part would replace the compression adjuster that I saw when I did my bike.

To remove the compression adjuster valve follow steps 1 - 6 in my original post. Once you have them out you'll be able to compare the adjuster you've removed with the pictures on the link you sent.

NOTE: If you do remove the compresison adjustment valve, you'll need to (as a minimum) change the fork oil, because you'll almost certainly lose some in the process and then you won't know what the total quantity is each side.

If you're not at all sure it would be wise to give your forks to someone who does - after all they're the front of your bike and I wouldn't want to do a half-arsed job on something so important to my safety.

Best of luck.
Warrington
 

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Hi,

Thank you for the reply.

Ill have them checked by a workshop next week. Just the thing is i managed to turn out that one adjuster screw a few clicks and now it wont turn in again and the adjuster on the other side is completely stuck. In other words there is a slight difference in compression damping now... i still try with WD40.
 

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The link you sent for the replacement part looks different from the one I took off - although the link states its for a 1998 ZX6R, maybe the compression adjuster is for a set of USD forks (I'm sure later models of the ZXR went to USD forks) ? I can't see how this part would replace the compression adjuster that I saw when I did my bike.
Update : Now i emailed K-TECH about this and if they confirm it will fit ill order the adjusters plus harder springs and fork oil and take the bike to the workshop...
 

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maybe there was a misunderstanding. the compression adjuster screw is in the bottom part of the fork leg.

i got this insctruction for removal :

To remove the std adjuster you need to remove the pin in the side of the fork leg, to do this you need a 3mm drill and a stud extractor to pull out the pin.
 

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Great write-up, thanks! Just went through this process yesterday so thought I'd compare notes :)

One thing I would add for anyone else coming across this is that you can avoid the need for any special tools for tightening the cartridge bolt by temporarily reassembling the fork to put pressure on the cartridge - this gives plenty of resistance for torquing up the bolt and barely adds any time.

Oh and I tried for over an hour to get my hardened dust seals off with no luck until I tried heating the metal below the seal with a blow torch until it came off with ease (took five minutes). Apparently this can damage the clearcoat but I couldn't see any visible signs.

I'm a very amateur home mechanic so take a handful of salt with all of the above and check with a professional if you have any doubts.

As the OP stated, it's really not a hard job. Just make sure everything goes back in the same way it came out and you can't really go wrong. :)
 
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