Easy fix to a slipping clutch?

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my77stang · #1 Unread post by **my77stang** » Sat Jun 03, 2006 1:28 pm

First i wanna thank those who put me in the right direction on the "running like crumb over 4000 rpm" problem.

on to my next dillema.......

the bike im working on is a 82 kaw kz750r1 gpz

the clutch lever has to be let ALLLLL the way out for it to go into gear - (and at that point there is no tension on the clutch cable at all). we tried changing the oil, using 20-50 motorcycle oil for wet clutch bikes, and added a 1/2 quart of STP super thick oil treatment to it. still we have the same problem - while riding if we dont rev it up very slowly it starts slipping, it will do it in any gear and at any rpm.

is there any adjustments inside where the actual clutch is located? if not how hard is it to change these things?

any info will be greatly appriciated, im ready to drive this bike off a cliff.

Thanks!!

Shane

BuzZz · #2 Unread post by **BuzZz** » Sat Jun 03, 2006 6:23 pm

If you have no tension on the clutch cable, and your getting slippage, your pretty much left with replaceing the plates to fix it. The plates are worn or glazed and the only proper fix is replacement.

my77stang · #3 Unread post by **my77stang** » Sun Jun 04, 2006 2:38 am

well that just figures

any good sources for aftermarket clutches? i dont even know where to begin looking?

thanks for the input =)

-Stangy

my77stang · Sun Jun 04, 2006 10:56 am

i just broke everything down, the steels look great, and the clutches themselves look fine too. they dont appear to be glazed, and the friction plates still have a good amount of meat to them (they still have the raised squared off high spots of friction material on them)

if anyone has thickness specs for this it would be greatly appriciated. im considering shimming the springs to add some more apply pressure. has anyone played with a mod such as this?

Thanks again for all your help.

-Stangy

my77stang · #5 Unread post by **my77stang** » Sun Jun 04, 2006 4:43 pm

ok, shimmed the springs - seemed to help but did not fix the problem, looks like its time for a clutch even though these look good.

im thinking this is a good trick for better holding pressure on a working clutch though, free and easy to do =)

BuzZz · #6 Unread post by **BuzZz** » Sun Jun 04, 2006 5:03 pm

Plate glazing may or may not be easy to eyeball. Especially if it is a chemical/additive issue. And a measurement against factory toleranecs is definately needed. As well as a measurement of the clutch springs for hieght.

If you have coil springs and not a diaphram syle spring, it is possible to put washers under each spring and maybe get some bite from that, but it's an afroamericanguy-rig fix at best. We used to do it on our motocross bikes (old sparkplug washers worked well for most bikes at the time) in the 80's for the last moto if you were particularly hard on the clutch that day, and needed one more race outta your toasty clutch pac.... we also used to drop the oil and run ATF in the gearbox, it helped the clutch bite alot.... but those were old 2-strokes. That kinda garbage will kill your modern 4 stroke engine.....

niterider · Mon Jun 05, 2006 12:05 pm

I think that the STP oil treatment in the oil only makes matters worse because it is very slick. It will make the clutches slip. You will need to change oil and clean the STP off of the clutch disks. But it also sound to me that the disks are worn thin. Hope this helps you.

my77stang · #8 Unread post by **my77stang** » Tue Jun 06, 2006 2:38 pm

i got the shim idea from working in a auto machine shop and doing heads all the time - shimming springs to add pressure is common.

as for the STP, i figured it would help seeing as how its super duper thick..... but alas, another 40 bucks thrown at the bike is unavoidable.... shame its such a P.O.S. LOL

another thought i had was this....

theres a rod that goes thru the crankcase which pushes the clutch pack apart when you pull the lever - at the end of this rod theres what kinda looks like a engine valve (stem and a flat head) well this made me think, if i put that into the valve stem resurfacer at work and took say .005-.010 off the tip, it would let the clutch assembly squeeze down that much further. in essence, decreasing the clearance between the clutches.

for a 200.00 bike - is this worth doing? then changing the oil and scuffing all the clutch plates?

.......maybe im just crazy?!?!

niterider · #9 Unread post by **niterider** » Tue Jun 06, 2006 3:52 pm

Have you priced the clutch plates? That may be the best way to go. I don't think that grinding the rod down is going to fix it.

ejshotgun · Tue Jun 06, 2006 7:12 pm

Get a Manual it’ll pay for itself the first time you open it.

Clutch plates
The above is the link to Z1Enterprises where I get most of my parts.
I'm not familiar w/your model but the way you described the workings of the clutch it sounds like mine. On the left side there should be an access plate and under here there is an adjustment for the clutch. This is what pushes on the rod you described.
Be sure and dump the oil and replace as already mentioned. STP aint good for anything in that motor.
I had similar probs w/mine a while back and was able to adjust it where it would work ok until I got on it real hard and then it would slip. So I wound up replacing the clutch pack (only the fiber plates).

Happy wrenching