GPZ550 (1983) clutch help

Have been doing a rebuild and now riding around but the clutch is giving me problems. I have gone through the adjustment process so I think my plates need replacing so just asking for advice before I start ordering parts. When riding I can change through the gears fine, when coming to a stop with the clutch pulled in the engine is almost stalling and impossible to get back into neutral, if I adjust the cable a fraction I start to get clutch slip. Thanks in advance.

Channo

How much freeplay do you have at the lever?

I set the free play on the lever as per the manual, everything else is set up to the manual specs . Haven't done a clutch before but looks like I am about to learn

Read a few times on here lately that the manual is wrong on some 550s but not sure if its on the GPZ too....... read clutch problems farther down and let Loudhvx chime in before you tear into it....... using bike oil anymore is a must too but won't effect the adjustment your describing.

How old is the cable? If you dont know, I would replace it before moving forward with disc replacement.
You have nothing to lose,...

If you adjusted the clutch per the manual you shouldn't have any clutch drag at idle. Sounds like the clutch plates are warped.

Regarding the slippage, that's typically due to sagged out clutch springs. A lot of people blame the clutch plates needlessly for slippage when the problem is the springs.

At minimum I'd get new OEM springs and a clutch cable if yours is old. Grease up the clutch actuation mechanism when you go to change the cable and adjust the ball/ramp mechanism per instructions in your factory manual. While the clutch is apart measure the fiber plate thickness and compare to the spec in your manual, also check flatness of the steel plates and replace parts as needed.

Channo wrote: I set the free play on the lever as per the manual, everything else is set up to the manual specs . Haven't done a clutch before but looks like I am about to learn

In what direction are you turning the clutch release adjusting screw? On some models you're supposed to turn it counterclockwise first until hard to turn, then clockwise 1/4 turn. some aftermarket & factory manuals are ambiguous & don't provide the direction. the owner's manual may have the specific procedure.

Yes, it's hard to locate the correct procedure in the manual since you have to weed through the appendices, and the clymer is vague, and may be wrong.

gpzweb.s3-website-us-east-1.amazonaws.com/ClutchReleaseMech.GIF

If it's been sitting the plates could be stuck together. You can take them out oil them and put them back in and see how it works.
Steve

Thanks for the ideas, will drain the oil and strip down over the weekend and make a decision if the plates need replacing . Let you know what the conclusion is

Channo wrote: Have been doing a rebuild and now riding around but the clutch is giving me problems. I have gone through the adjustment process so I think my plates need replacing so just asking for advice before I start ordering parts. When riding I can change through the gears fine, when coming to a stop with the clutch pulled in the engine is almost stalling and impossible to get back into neutral, if I adjust the cable a fraction I start to get clutch slip. Thanks in advance.

Channo

If you're clutch-in at a stop and yet, it feels like you are stalling the engine out, then, you have NOT released the clutch fully and thus putting drive-load on the engine. Assuming your clutch cable isn't stretched beyond functional range; this means you need to adjust the clutch to press on the the rod sticking thru the inner case wall on the 550 so it absolutely has released but only just so.

I just did this about a week ago on my 550a, mostly because I felt my clutch was "grabbing" too soon (like the first mm of release of the lever when it started grabbing - too soon for my liking).

The problem I ran into is there didn't seem to be enough adjustment travel at the case adjuster screw AND the non-factory manual explains it incorrectly or perhaps I should say doesn't explain at all which direction of adjustment at the screw does what...

I followed the procedure to loosen the intermediate cable adjustment and the lever and tried a few times to bring the adjustment at the case into range with little or no success. Of course I was assuming "righty tighty, lefty loosey" would be how that adjuster screw would work at this moment, which it turned out was wrong. Plus that adjuster screw has a limited adjustment range.

Finally, in frustration, I decided to pull the starter cover, peg, shifter and case cover off and have a peek. (You could actually shine a flashlight up from the ground and peek down inside where the starter cover comes off to see the release inside the case).

My 550a has the 3 bearing system which I think is what yours has too.
When I got the case cover off, I noticed how dry everything was, so I cleaned it and greased it with some moly grease.
You'll have to be careful here since if yours is "dry" too, you may find one or more of the ball bearings can just fall out of the captive plates they are sandwiched into. This is why I greased mine to alleviate friction here and to keep the balls in their place while I experimented.
Inspect these plates and the ball bearings closely and you'll get a complete understanding of how the cable pulling motion is translated into a clutch releasing inside the engine. The captive balls travel up small ramps in the plate which causes the two plates to separate further but you only have a total expansion of the height of the ball bearing... The adjuster screw simply moves this plate into an operable range against the rod sticking out of the inner case wall.

Prior to removing the case cover, I loosened the lock-nut on the adjuster and then once visible, I played with the adjuster to see how it affected travel of the plate that pushes against the clutch rod.
Basically, you can adjust the screw in the case cover and watch as the ball bearing plate sandwich moves away from the case cover bore meant to hold it. Moving this bearing plate out of the bore is creating inward deflection and would put more inward travel on that rod and therefore cause the clutch to release more that it was previously.

So I tried adjusting it to stick out of the case bore a couple of mm's further inward to begin with. Then assembled the case cover and finally the cable joints. These cable adjustments were done watching the clutch lever so I could watch the lever slowly close-up. I did this to put no preload on the cable until I got to the handle adjuster to get that 1/8" play.

The first couple of times I did this, I discovered how close the tolerance of this system really is and "SNAP!"
If you get it too "tight" you can cause the release mechanism in the case (the 3 ball bearing cage assembly) to rotate too far and actually "snap" out beyond it's range.

Understand, that as you pull that clutch lever, pulling the cable, pulling the release arm in the case. This cable movement is translated into a rotation of that 3-bearing plate and it cannot be rotated too far forward before it will "snap" up beyond it's range, under spring load and suddenly your clutch lever will drop as if the cable broke.
The arm inside the case cover, where the cable actually connects only has a range of motion of between 6 and 7 on the clock dial. If your cable is adjusted tightly, you can actually pull that release arm so far forward that it will move up beyond it's range and due to return spring load pop up and thus move into the range of 8 to 10 on the clock dial where it cannot return from.
So case cover has to come back off, manually move the release cage/arm back into the 6 position... start again.

This is super tough to explain. Wish I had taken pictures but my hands were pretty greasy at the time

After some trial and error and about 1 hour in the garage, I finally found that I could adjust the bearing plate outward from the case enough to put it in a range of motion that would release the clutch fully (so it doesn't slip in-gear) and yet completely unloads it too when I pull the lever in at a stop. Now when I release the lever to move forward, the lever moves maybe 5-6mm from the grip before the clutch begins to pull which is where I've always found it most comfortable.

Dayum, that was probably as clear as mud I bet...

Thanks wrenchmonkey. It is really clear as I've had that cover off and been adjusting all week. Does't matter what I do I can get the correct setting. The best I can do is adjust so it's not slipping but just impossible to get into neutral when coming to a stop and can,t hold for long when stopping with the clutch pulled in. Going to drain the oil this weekend get the cover off and check out what the plates look like - not that I know what to look for, hopefully the manual is a good reference point. Someone did mention in this thread that the plates might be sticking. As this is an old bike and I don't really know what K's it's done a very good chance that it's stuffed.