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Mumbles
26th September 2004, 16:50
Hi guys can anyone help?
1989 Kawasaki ZXR750 H1
I have noticed that the clutch is starting to slip under excessive load, I have replaced the clutch fluid when I did the breaks last, and have re-bleed them just in case.
Its only happens sometimes so I don't really notice it until I pull the throttle all the way back. :whistle:
I have asked around about possible cheap fixes and been told I can repack the clutch assembly with 1 extra plate? (These answers have not come from actual mechanics)
It just so happens that a mate of mine has just replaced his clutch (Another 89 ZXR750 H1) and has kept the old friction and steel plates from his bike.
My questions to the experts out there is
Can I just add another plate?
If is yes which one do I add? Friction or Steel?
What order would I put this extra plate in?

Any help would be appreciated (I do have the Haynes manual to help me work off)

speedpro
26th September 2004, 20:11
Time for replacement clutch plates. You should be able to get aftermarket ones for a reasonable price I think.

If you really MUST add extra plates you need to put in a pair to actually make any differance. I'm not real familiar with the ZX clutches but as with others I would thin the steels and possibly take a whisker off the alloy baskets where they clamp the clutch pack so that the total assembled clutch thickness is the same with the extra plates as without.

dhunt
26th September 2004, 21:04
How bad is the slippage? My bike had a little at full revs putting washers on the clutch springs increased the tension a bit and now it doesn't have any slippage. Or if you think that is too doggy I'm sure you can get new springs with slightly higher tension.

David

Velox
26th September 2004, 22:43
I'm having some issues with the clutch slipping too. Does anyone know roughly what it'll cost to get new plates in?

F5 Dave
27th September 2004, 09:21
The extra steel plate is only acting as a preload, which can almost help, sometimes. You can also preload the springs, often sparkplug washers are the right size to fit over the posts & not bind.

On the 750 I put in some EBC stiffer clutch springs. They were pretty damn stiff so having 6 springs I could spread the load & only put a stiff one every 2nd one & leave the std ones in the other posiís. Worked a treat.

When you take it apart you will have to check the clutch basket is not too notchy (can file out small notches) else the plates can Ďhang upí on them. Check the steels are not glazed. Can resurface them rubbing them figure 8 on smooth concrete (clean before reusing them). But check they are not warped placing them on glass, or against each other & rotating looking for gaps. Measure the friction plates to see they havenít worn too much or you will be in for replacement. When they get bad you will notice a heck of a pong & the oil has been contaminated. New plates likely only option, new oil at that stage too.

Speedpro, must get a min to pull the Basket to send you, havenít forgotten.

Velox, how bad is the slipping?

Mumbles
27th September 2004, 19:29
Thanks alot lads,
Looking like I might take the spring option first, then the 2 plates....
if all else fails its $140 for the plate kit....
Thanks for the help, I'll keep ya posted as to what happens... Whose the best person to deal with in Auckland for Kawaka parts now that power sport are no longer supplying them....? or can I go none factory?
Mumbles

Velox
27th September 2004, 23:22
Velox, how bad is the slipping?
It's just a high revs - either when I lose even a tiny bit of traction because of the road surface (more than it would usually) or just when I'm accellerating hard in the higher gears. In both cases it'll rev high for a while and then decide to pick up finally. It is survivable though - it doesn't affect me at 'normal' speeds/accelleration too much. But I guess it could get worse and it's not ideal really. If it isn't too pricey to replace the plates I may aswell get it sorted at some stage!

F5 Dave
28th September 2004, 08:42
V. Sounds like it is still borderline, but if it is allowed to slip for too long (the action of slipping wears it quicker) it will go very quickly into chronic & even faster into outright failure where it slips so much you get no forward motion which is a trifle embarrassing & more than moderately inconvenient.

It may be able to be fixed with some stiffer springs or extra preload, but if you can spare the money you may find new plates better than having a stiffer clutch pull. Depends how stiff it is now.

Depending on how common your bike is (or if it shares the plates with another common model), you will be able to get after market plates no worries. Plate kits vary in price. Usually genuine are frighteningly expensive, but sometimes they price competitively. Another option is 2nd hand. Either the wrecker will know off the top of their head what will match it, or they will say to bring a plate in to match up, or just no depending if they have had their coffee that morning.

As far as expense, a large portion will be the labour to pull the plates out. Obviously if you can do it yourself or have someone who can it will be remarkably cheaper.

Stevo
28th September 2004, 09:34
It may be able to be fixed with some stiffer springs or extra preload, but if you can spare the money you may find new plates better than having a stiffer clutch pull. Depends how stiff it is now.

Depending on how common your bike is (or if it shares the plates with another common model), you will be able to get after market plates no worries. Plate kits vary in price. Usually genuine are frighteningly expensive, but sometimes they price competitively.

As far as expense, a large portion will be the labour to pull the plates out. Obviously if you can do it yourself or have someone who can it will be remarkably cheaper.

I have a 250 as well and found that there was very little price difference between genuine and non genuine (less than $10) and did it myself which was remarkably easy. Just need to make sure you order a gasket as well. With some models you can get heavier springs rather than replace the clutch plates but unfortunately I couldn't. If you can get heavier springs for your model of bike then this is the cheapest option. Not sure how long term it is though???:spudwhat:
My old plates didn't even look very worn but certainly a huge difference since installing the new plates.

Just my thoughts :ride:

Velox
28th September 2004, 14:59
Cheers for that Dave! :niceone: I think my bike would have the same plates as a CBR250 so it shouldn't be too bad from that perspective. I'll check out prices down at the shop and see where to go from there.

DEATH_INC.
28th September 2004, 16:43
Give mike at mt eden a call,he's doing kwaka's now and can get genuine and aftermarket from cheap premiers to not cheap barnett.
I often run an extra steel to preload the clutch a bit more(even with new plates),just put it in with the first steel you put in(so the two run together).
I will advise against using surflex plates at this point,I've run three of them and every one has stripped the lining off the plates almost straight away :mad: (they did warranty the last one though,to their credit)

F5 Dave
28th September 2004, 16:51
I was going to mention my experience with Surflex but thought maybe it was isolated, mine seemed to just disintegrate the lining around the tabs, but it put a bunch of junk in the engine.

DEATH_INC.
28th September 2004, 17:01
Mine just disintegrated,a couple of the plates had no lining on one or both sides and others had complete bits missing.....many large intact bits in the bottom of the engine/clutchcase...

Madmax
28th September 2004, 18:36
seems to be a common problem ZXR750s
(have had it happen as well)
replaced the springs
all OK

speedpro
28th September 2004, 20:11
I've got a Barnett kit in my Z and it never slips and always takes up hard.

DEATH_INC.
29th September 2004, 18:09
I'll second that!I had a barnett in the Turbo and it was great,'till it broke a couple of plates......(not the fault of the clutch,it does it regularaly...).