KZ250 Clutch - what needs replacing.

My KZ250 clutch is at the very end of it's travel, and also slips around 8000rpm. So it looks like the clutch will need doing. I've done motorbike clutches before (well, once before), but in that case all the parts were obvious, available and cheap.

Without pulling the clutch apart, what parts will I need to replace? I will obviously need new friction plates. I probably need new springs too, but they seem hard to come by. I can find springs, and I can find plates, but finding them together seems difficult. The killer here is postage - in Australia most parts seem to come from the USA (funny for a Japanese bike, but whatever). So my $15 springs end up costing $55. If I can combine postage for the springs and the plates though, it's not so bad.

So are the springs an essential swap-out part when doing the clutch? Normally I would just replace them, but I will likely be paying three times the price of the springs on postage as well.

For the record, I've been looking at EBC parts - number CK4425 for the plates and CSK7 for the springs. Are there any other brands I should be looking out for? Or can anybody suggest where to get these from?

Thanks in advance.

Irish Yobbo wrote: My KZ250 clutch is at the very end of it's travel, and also slips around 8000rpm. So it looks like the clutch will need doing. I've done motorbike clutches before (well, once before), but in that case all the parts were obvious, available and cheap.

Without pulling the clutch apart, what parts will I need to replace? I will obviously need new friction plates. I probably need new springs too, but they seem hard to come by. I can find springs, and I can find plates, but finding them together seems difficult. The killer here is postage - in Australia most parts seem to come from the USA (funny for a Japanese bike, but whatever). So my $15 springs end up costing $55. If I can combine postage for the springs and the plates though, it's not so bad.

So are the springs an essential swap-out part when doing the clutch? Normally I would just replace them, but I will likely be paying three times the price of the springs on postage as well.

For the record, I've been looking at EBC parts - number CK4425 for the plates and CSK7 for the springs. Are there any other brands I should be looking out for? Or can anybody suggest where to get these from?

Thanks in advance.

Well I live in the USA I changed out my friction plates and springs. I didn't look at brands I just bought what came up on Google for a kz650. As far as shipping goes for you I would just bite the bullet. Maybe ebay? Lots of ppl offer free shipping mostly from China though.

I think I will just need to bite the bullet.

The big question is, will any CSK7 spring set work for my bike? There are plenty of motorbikes that use the CSK7, but they are all different makes and models, and some use more and some use less springs. Will these springs really work for my model, or is that number a model range, and I need to choose my bike for that range?

Irish Yobbo wrote: I think I will just need to bite the bullet.

The big question is, will any CSK7 spring set work for my bike? There are plenty of motorbikes that use the CSK7, but they are all different makes and models, and some use more and some use less springs. Will these springs really work for my model, or is that number a model range, and I need to choose my bike for that range?

How did u come across them? And how many springs does your bike take??

Check your plate thickness and spring free length first, shimming springs with washers is a work around.

blink543 wrote:

Irish Yobbo wrote: I think I will just need to bite the bullet.

The big question is, will any CSK7 spring set work for my bike? There are plenty of motorbikes that use the CSK7, but they are all different makes and models, and some use more and some use less springs. Will these springs really work for my model, or is that number a model range, and I need to choose my bike for that range?

How did u come across them? And how many springs does your bike take??

According to this link I need 5. The part number I know because some of the ebay listings for EBC springs for my bike use this code (CSK7). Frustratingly, the EBC catalog does not list the KZ250. From what I understand, it is a pack of 6 to make it compatible with more models, but I only need 5.

The bike has 64000kms on it which is a lot for a 250, so I'm pretty convinced there's a bit of wear in there. I just don't want to replace the plates and not fix the problem.

I would not buy EBC parts; I would buy genuine Kawasaki parts.

Assuming there is a t lest 1 Kawasaki dealership in Australia, if I lived in Australia would not buy from overseas and pay the high cost of shipping. I would simply buy the genuine Kawasaki parts from that dealership (assuming the parts are available).

Based on the information at www.dealercostparts.com (see image below) it appears that the friction plates and clutch springs are still available for the KZ250. Notice in the parts list below the diagram neither of those parts is marked "Not Available." I recommend you check with your local Kawasaki dealership to verify this, and if it is true order from them. Ed

Have you tried adjusting the clutch to add freeplay into the system? Most of the time a simple adjustment and replacing the stock springs with fresh stock springs will fix the slipping issue.

Nessism wrote: Have you tried adjusting the clutch to add freeplay into the system? Most of the time a simple adjustment and replacing the stock springs with fresh stock springs will fix the slipping issue.

Me too. Yes a lot of miles but that 20hp-25hp motor seems awful puny to tear up 7 friction plates in the clutch....assuming they have not been fouled with friction modifiers by using the wrong oil for too long. That is the $64,0000 question to me.

For a few dollars and a couple-three hours in an afternoon, FIRST:
I would drain ALL the oil, pull the clutch cover, remove the five spring bolts and springs, slide the clutch pack out, clean the Hell out of the friction and steel plates, (check the actual thickness of the friction plates, compared to the service manual) check the steel plates for warpage and spot-streak bluing. You can lightly scuff up the steel plates a tiny bit with some 240 grit wet-dry paper but clean them very well.
Reinstall the friction and steel plates with a little film of JASO-MA rated oil, and put the springs back in but, with 5 thin shim washers under the five spring bolts in case the springs are not quite up to snuff.
Now refill with PROPER JASO-MO rated WET CLUTCH engine oil ... adjust the clutch cable and release - free play correctly... then decide if you really need to spend another $85-$120 on clutch parts.
Use your own judgement from that point on as you at least now, know how to flip the clutch pack in and out.

I have bought a number of well used bikes over the years with a "substantial" discount because of being told "it has a bad clutch" ... and found that proper cable, clutch pats cleaning, free play adjustments and that little trick ... had them working pretty good... with nearly no money invested except, time, a few bucks for 4 to 6 shims and fresh oil.

missionkz wrote:

Nessism wrote: Have you tried adjusting the clutch to add freeplay into the system? Most of the time a simple adjustment and replacing the stock springs with fresh stock springs will fix the slipping issue.

Me too. Yes a lot of miles but that 20hp-25hp motor seems awful puny to tear up 7 friction plates in the clutch....assuming they have not been fouled with friction modifiers by using the wrong oil for too long. That is the $64,0000 question to me.

For a few dollars and a couple-three hours in an afternoon, FIRST:
I would drain ALL the oil, pull the clutch cover, remove the five spring bolts and springs, slide the clutch pack out, clean the Hell out of the friction and steel plates, (check the actual thickness of the friction plates, compared to the service manual) check the steel plates for warpage and spot-streak bluing. You can lightly scuff up the steel plates a tiny bit with some 240 grit wet-dry paper but clean them very well.
Reinstall the friction and steel plates with a little film of JASO-MA rated oil, and put the springs back in but, with 5 thin shim washers under the five spring bolts in case the springs are not quite up to snuff.
Now refill with PROPER JASO-MO rated WET CLUTCH engine oil ... adjust the clutch cable and release - free play correctly... then decide if you really need to spend another $85-$120 on clutch parts.
Use your own judgement from that point on as you at least now, know how to flip the clutch pack in and out.

I have bought a number of well used bikes over the years with a "substantial" discount because of being told "it has a bad clutch" ... and found that proper cable, clutch pats cleaning, free play adjustments and that little trick ... had them working pretty good... with nearly no money invested except, time, a few bucks for 4 to 6 shims and fresh oil.

You're probably right, it might be worth pulling it apart just for a look. However I'm pretty convinced it's not adjustments. The cable was freshly lubed when I did the brakes, and it has the tiniest bit of slack before taking up. It only need to move a few mm at the clutch to disengage.

Also, when I got the bike I'm pretty certain it had the wrong oil in it. If you started it up and put it in first, it would immediately stall when cold. One of the first things I did was change the oil and that fixed the problem, but I have no idea how long it was like that for. So the combination of the wrong oil and high mileage was leaning me towards replacing parts.

Irish Yobbo wrote: You're probably right, it might be worth pulling it apart just for a look. However I'm pretty convinced it's not adjustments. The cable was freshly lubed when I did the brakes, and it has the tiniest bit of slack before taking up. It only need to move a few mm at the clutch to disengage.

Also, when I got the bike I'm pretty certain it had the wrong oil in it. If you started it up and put it in first, it would immediately stall when cold. One of the first things I did was change the oil and that fixed the problem, but I have no idea how long it was like that for. So the combination of the wrong oil and high mileage was leaning me towards replacing parts.

The clutch cable should have more than "the tiniest bit of slack". This suggests the cable is too tight.

I'm not a fan of shimming clutch springs. Just get new ones. Worst case you buy clutch parts later, in which case you will already have the springs.

Oh, and the people on this site seem quite freaky about oil. Some MA2 oil is fine, like Shell Rotella 15W-40. But just about any type of diesel oil is just as fine, even though it's not MA certified.

Nessism wrote:

Irish Yobbo wrote: You're probably right, it might be worth pulling it apart just for a look. However I'm pretty convinced it's not adjustments. The cable was freshly lubed when I did the brakes, and it has the tiniest bit of slack before taking up. It only need to move a few mm at the clutch to disengage.

Also, when I got the bike I'm pretty certain it had the wrong oil in it. If you started it up and put it in first, it would immediately stall when cold. One of the first things I did was change the oil and that fixed the problem, but I have no idea how long it was like that for. So the combination of the wrong oil and high mileage was leaning me towards replacing parts.

The clutch cable should have more than "the tiniest bit of slack". This suggests the cable is too tight.

OK I might need a bit more info on this. If there's more slack (let's say 5mm of extra cable) then my clutch lever will be loose (by a couple of cm). As I understand it, when the clutch is 'off', there should be no pressure from the cable at all, so whether there is a tiny bit of slack (1mm extra cable) or more(5mm extra cable) will make no difference to the clutch apart from the lever travel and the take-up point.