Topic: (Another) clutch-not-grabbing issue after install

[max]

My bike: '78 CB750K

So my clutch started getting weak at ~30k miles, so I thought it was time to drop in some new discs. I picked up the Barnett clutch kit w/discs, plates and springs and spent several hours last weekend swapping everything out and putting it back together. I decided to use only the discs from the kit, went with OEM springs instead of the Barnetts and stuck with the existing plates, since they were still in great shape and of better quality. Once done, I go for a ride and I'm able to shift through gears with almost zero effort--as if the clutch wasn't disengaging. I was even able to shift easily with no clutch. I go back in and double-check everything, using some helpful advice from these forums. I double-checked that the teeth on both ends of the basket were locked together, turned the adjuster screw 1/4 turn out from the point of resistance, measured the discs thickness and plate warpage and torqued everything to specs. I'm also pretty sure that the cable is just fine, since I can see the clutch lever for the lifter moving up and down as it should. The one thing I should note is that the kit came with 7 plates, but my model uses only 6; there's one "double" plate "B" in place of 2 regular plates. Aside from that, I think that I crossed all my Ts. So, I'd like to hear your ideas as to where I could've screwed up ;-) Any suggestions are very welcome, since I'm really itching to go for a ride.

Thanks,
Max

[Black 750K8]

My bike: '78 CB750K

So my clutch started getting weak at ~30k miles, so I thought it was time to drop in some new discs. I picked up the Barnett clutch kit w/discs, plates and springs and spent several hours last weekend swapping everything out and putting it back together. I decided to use only the discs from the kit, went with OEM springs instead of the Barnetts and stuck with the existing plates, since they were still in great shape and of better quality. Once done, I go for a ride and I'm able to shift through gears with almost zero effort--as if the clutch wasn't disengaging. I was even able to shift easily with no clutch. I go back in and double-check everything, using some helpful advice from these forums. I double-checked that the teeth on both ends of the basket were locked together, turned the adjuster screw 1/4 turn out from the point of resistance, measured the discs thickness and plate warpage and torqued everything to specs. I'm also pretty sure that the cable is just fine, since I can see the clutch lever for the lifter moving up and down as it should. The one thing I should note is that the kit came with 7 plates, but my model uses only 6; there's one "double" plate "B" in place of 2 regular plates. Aside from that, I think that I crossed all my Ts. So, I'd like to hear your ideas as to where I could've screwed up ;-) Any suggestions are very welcome, since I'm really itching to go for a ride.

Thanks,
Max

That sounds like a good thing I don't think I understand what you think is wrong? Buy the subject title are you saying it is slipping the engine speeds up but the bike does not move as it should?

[bjbuchanan]

Compare the stack height of what you pulled out vs what you put in. If you haven't lost the thrust washer and didn't mismatch, break pressure plate... that stuff then check out what you are working with now. The thickness of that double plate is a quick thing to worry about with mixing and matching.

Also, did you soak them in oil for atleast a couple hours? not doing it usually results in a clutch that is partially engaged, making shifting harder, but it is just another one of those variables to think about

[max]

Thanks for the helpful suggestions!

@Black 750K8 - I guess I almost made it sound like the clutch was shifting too well. Not true. Really, the problem is that there's hardly a friction point any more. I feel an extremely faint grab for barely 2-3 mm of travel and that's it. It's weird though, it's not exactly slipping as it was before, but it definitely doesn't feel right.

@bjbuchanan - I'm afraid that I didn't measure the original setup before I swapped in the new discs, but I did compare the thickness of old discs vs. new, and that checked out OK. I also only soaked the discs for 10 minutes. That's what was suggested in the instructions that came with the Barnett kit at least. Lastly, which washer is the "thrust washer"? ;-) I don't think I lost anything but, if I did, I wouldn't be surprised if it was a washer or something small like it.

[martin99]

Take it out, double check you have everything as it should be, soak those discs properly (personally I would do this for six hours at least), put it back together and re-adjust.