Need some help changing (inner) oil on new CC 48mm Zokes.

CDBiker220

New member
Hi, decided to tear into the forks on my 2012 300. I got as far as taking the cartridge out and seperating the inner and outer fork tubes (needs seals, going to look into yamaha seals, i assume the 2006-2012 yz250/450 48mm seals should fit). Only about 260cc of oil came out...very very contaminated, was all silver looking with metal contamination. Bushings looked fine though.

Anyways, backing the pfp knob out i actually cracked open the cartridge and was able to unthread the cap but the whole pfp assembly only comes out some of the way depending on where I move the damper rod and no oil comes out even though i can see the pfp spring and such. I only what to take apart enough to change the inner oil, dont really wanna tear into valving or anything else. Can someone tell what to do to get the inner cartridge oil out. I saw a few people write up how to fill/purge the cartridge but no real explanation on how to remove the oil, just dont want to disassemble more than I have too. I still have to figure out how to make a tool to retighten the cartridge cap as I know I shouldnt be using the pfp knob to do it like how it came appart. Thanks!
 
Hi, decided to tear into the forks on my 2012 300. I got as far as taking the cartridge out and seperating the inner and outer fork tubes (needs seals, going to look into yamaha seals, i assume the 2006-2012 yz250/450 48mm seals should fit). Only about 260cc of oil came out...very very contaminated, was all silver looking with metal contamination. Bushings looked fine though.

Anyways, backing the pfp knob out i actually cracked open the cartridge and was able to unthread the cap but the whole pfp assembly only comes out some of the way depending on where I move the damper rod and no oil comes out even though i can see the pfp spring and such. I only what to take apart enough to change the inner oil, dont really wanna tear into valving or anything else. Can someone tell what to do to get the inner cartridge oil out. I saw a few people write up how to fill/purge the cartridge but no real explanation on how to remove the oil, just dont want to disassemble more than I have too. I still have to figure out how to make a tool to retighten the cartridge cap as I know I shouldnt be using the pfp knob to do it like how it came appart. Thanks!

Awkkk! Careful with that PFP adjuster, as in, stop before you start unthreading the cartridge cap ;) Oops, you've already done that. Best course now is to get a KYB cartridge cap removal tool and relieve it for the PFP adjuster.

There is a lot of vacuum on the compression piston - you'll have to wiggle it and pull hard but it should pop right out and, if you're not careful, dump a bunch of oil everywhere.

When everything in apart stroke the legs to encourage any residual oil to exit. Stock refill is 310cc in the outer legs and 210cc in the cartridges.
 
Yeah, like Steve said, you need a KYB cart tool- but even then they're not all the same.

You need one that's hollowed out so it'll fit over the PFP knob...

Then it's pretty much like the KYB cart.
 
Thanks for the help guy's. Good thing I didnt start tearing into it more before I asked. Going to stop at a local suspension shop on the way home and pick up some 48mm KYB fork seals, as I've heard they work well (both performance and durability), the SKF Blue/Green looking seals that were originally in the fork didnt last too long. Planning to use GMP's instructions in post #166 in the link below to fill and purge air/excess oil. If their is better instructions/method out there let me know.

http://www.gasgasrider.org/forum/showthread.php?t=11075&page=17
 
Thanks for the help guy's. Good thing I didnt start tearing into it more before I asked. Going to stop at a local suspension shop on the way home and pick up some 48mm KYB fork seals, as I've heard they work well (both performance and durability), the SKF Blue/Green looking seals that were originally in the fork didnt last too long. Planning to use GMP's instructions in post #166 in the link below to fill and purge air/excess oil. If their is better instructions/method out there let me know.

http://www.gasgasrider.org/forum/showthread.php?t=11075&page=17

When the nok seals leak too....give me a call. I have the setup that will last years and that can be removed and reinstalled many times over and are super slippery once broken in.....wheh....out of breath.

Rob
 
You won't find a tool on the shelf, you'll have to make one. Cheap KYB tool from Rocky Mtn., hollowed out, welded to an old 1" socket.



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Actually, I've got one or 2 of these in the shop. Work fine over the knob- have to pay attention, but work fine...

http://www.motionpro.com/motorcycle/partno/08-0373/

08-0373.jpg
 
I bought exact that tool. Local Yamaha shop had it in stock. So i finished one fork leg and going to put the other together tomorrow. I think I did a good job. I did however measure the springs (I'm sure they're stock) one measured 470mm the other measured 472mm (stock should be 475). I noticed their was basically no preload on them when in the fork. So i moved the preload clip down one position to get 5mm and 7mm of preload respectively. A little preload might not hurt as Im probably a bit heavy for the stock forks (185 lbs) but I know I'll be closer to 175lbs come summer time so i dont wanna buy heavier fork springs just yet. Was this a bad idea? Also, one side the oil in both the cartridge and outer oil was very silver/metallic looking, almost like overused tranny oil but thinner, but the other side was just green/brown and looked like other dirty fork oil ive seen. Kinda weird the oil looked different on both on both sides, but all bushings still looked new.

Just a note, The suspension was worked on before for the previous owner. I know that the PFP spring is one step lighter, stock main springs, 350cc oil in the outer cartridge(I put this much in the leg I finished), and the rebound was changed in the fork as well as the shock. Originally set up for A class/Local Pro 175lb rider.
 
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I saw that tool but passed as I was worried about the contact area and it slipping while leaning on it engaging the comp assy threads. It probably bottoms out on the PFP adjuster before the cap, right?

Stock preload with stock springs is about 5mm. I reset my clip to 0 preload, then added 2mm shims I made to the bottom of the fork under the springs. This should help the fork settle a little more with the stock PFP springs. Other than that I added rebound as well and removed free bleed, probably close to what was done to yours. I also had one cartridge with dirtier oil than the other, strange. I scrubbed them clean inside and out, and as far as I can tell the anodizing looks the same on both.

I really like the fork, its firm and you feel a lot of the trail but with no deflection thats a good thing. The PFP system is interesting but of limited use because of the stiffness. That was part of my reasoning for dropping the main spring preload, I can always make it up with more PFP if needed.

How did the procedure work out for you?
 
GMP - Your procudure seemed to work great. Im assembling the other fork tonight. That Tool worked really well. didnt bottom out on the pfp adjuster, but was slightly loose fitting and would slip if you were'nt aligned perfectly.

I am thinking of jumping into the shock soon...only other shock I've done is the dual ohlins shocks on an 81 Husky I do vintage races on (still had a nitrogen reservior like todays shocks) but I'm sure alot has changed. But I'll make a new thread when I get into that.
 
I've done the Sachs, but I don't have the needle for the Ohlins yet. Very close other than that. Big mess though until you figure your retention/oil collection system out.:eek:
 
I really like the fork, its firm and you feel a lot of the trail but with no deflection thats a good thing. The PFP system is interesting but of limited use because of the stiffness. That was part of my reasoning for dropping the main spring preload, I can always make it up with more PFP if needed.

The PFP is beneficial for compression, but I would think a stiffer main spring would help in holding the bike up in the stroke and returning the forks to full extension following an impact. Then again, that would require even more rebound damping ;)
 
Steve,
No problem with ride height, bike is up in the stroke nice. Pics of me confirm that. My only complaint is it could settle more, and I think that aggrevates the steering lock issue in tight slow turns. It just feels like it might have too much preload, so I dropped a few mm. Also added even more rebound this time in. The bike still liked the clicker wound into 5 clicks out with the free bleed removal.


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