clutch slipping

my clutch starts to slip whenever the rpm's get over 6-7k. i have plenty of free play at the clutch handle. the bike(1976 kz900) only has 18.5k miles on it. is this normal? i do not use additives in the oil, and the oil level seems ok. i cannot see a clutch assembly going bad with low miles on it.

have you tried adjusting it?

well, the freeplay at the handle is good. if the clutch was out of adjustment, would it only slip at high rpm's?
i am willing to try it if it would help.

what is it doing at 7K? That doesn't make a whole lot of sense to me. If it doing to slip it should slip from a dead stop, especially if you "get on it". I don't know what red line is for that bike, but I am assuming 10K so you don't have a tremendous amount left in it. I would think it may be more in your main jets not giving it enough fuel, but that is just my 2 pennies. Are you using full synthetic oil or oil with gas conservation properties (usually 10w30 and lower)? Those oils have friction modifiers in them. Just a thought.

try adjusting it,if that doesnt work pop the cover off and check your springs and plates.it could be just overpowering the clutch at higher rpms due to weak springs or worn or broken plates!goodluck,happy wrenching!

it seem to work fine till i get to about 5-6k. from then on if i roll on the throttle the rpm's will climb but not the speed. the clutch is slipping at around 6k. the freeplay at the clutch handle is ok.

Clutches always slip in high gear before they get bad enough to slip in the lower gears. The maximum load on a clutch is at the engines torque peak with the trans in high gear.
The adjustment on the cable is for cable adjustment, not the clutch, the clutch adjustment is on the side of the engine/trans cover. Generally it's a slotted stud with a lock nut.

thats part of the adjustment is adjusting the piece inside the cover,then you adjust the cable!

i'll try it at the side cover. thanks for the help, i do appreciate it.

Redline for a stock 900 is 9K rpm. If the clutch plates are worn, it will slip FIRST in 4th and 5th gears under acceleration. It won't slip when starting from a stop initially. The comments here leave me thinking that someone needs to explain how to adjust a clutch. That is the FIRST step before getting into the clutch itself. First is to loosen the tension on the cable at the mid-adjust point by turning the two adjusters toward each other. Then move the wheel adjust up near the switchgear till it is about 3/16" gap from the switchgear. Then take the slack of of the cable by moving the two adjusters away from each other at the mid-adjust point. At that point, get a 12mm wrench or socket and loosen the locknut on the adjuster on the countershaft sprocket and turn the adjust screw all the way IN till it lightly seats and then turn it out 1.5 turns (or whatever the manual states)... Leave the locknut loose and go out and ride the bike... you may need to adjust the screw in or out (I almost always have to adjust on the fly). If this doesn't cure your clutch slip... do this:

* drain oil
* remove clutch cover (right hand)
* remove five clutch springs. The Kaw Factory Shop Manual gives the minimum length each spring can be before replacment. A short spring indicates it has lost its springiness and the clutch won't work right. Don't replace with heavy duty springs unless you have a strong grip!
* pull out the 8 friction plates and 7 steel plates. You need a micrometer or caliper to measure thickness on the friction plates. If they are too thin or glazed, replace. Put the steel plates on a piece of glass to see if they are flat.
* put it back together in reverse order. If you remove the clutch basket for some reason, don't lose the small ball bearing that sits between the pusher and the rod.

Got a KZ440 with the same problem. thanks for advice gonna try it. Its the only thing left to do. Got a solution for rebuilding starter.:laugh: I used a Yamie starter core and placed the ends of my starter on it. works great with a little adjustmemt.

Thanks Again:cheer:

My clutch plates (friction) are black, and they're the stockers. Would this constitute glaze?