Topic: Clutch overheating? Now with 100% more extra broken! (and pictures)

[IainC]

I've been racking up the kilometers since I've finished the majority of work on my bike, and everything has been great except for this one problem I'm having.

It seems once I've been out for a bit and the bike is nice and warm, sometimes the clutch will fail to engage. The lever becomes very hard to pull, and the bike refuses to shift, I can't even get the pedal to move. This seems to happen when accelerating quickly or after I've been cruising for a bit. Mostly this is happening in second gear. If I need to come to a stop, I can't get my clutch to engage and the bike will stall. Sometimes this will happen for a few seconds other times up to a minute.

I've adjusted my cable at both the lever and the mechanism, and I've also adjusted the clutch itself as per instructions in the manual. When the clutch was apart this winter all disks and springs were well within spec.

Any suggestions?  

[MCRider]

I suspect a very fatigued cable. Is it new? Or old?

Your description of the symptoms seems a little off. If you are coming to a stop and it stalls, then the clutch is not DIS engaging. You say not engaging.

[IainC]

I suspected the cable as well as everything else seems to check out fine. I'm not sure the age honestly but this needs to be replaced anyways as its a little long for the new bars. Do you think the length could also be a problem? My buddy at the bike shop dosn't think he can easily get a shorter cable, so I'll need to do some research and see what I can find.

You've got me on the technicality, but I think you understand my situation, Disengage would be the correct term. 

[MCRider]

I suspected the cable as well as everything else seems to check out fine. I'm not sure the age honestly but this needs to be replaced anyways as its a little long for the new bars. Do you think the length could also be a problem? My buddy at the bike shop dosn't think he can easily get a shorter cable, so I'll need to do some research and see what I can find.

You've got me on the technicality, but I think you understand my situation, Disengage would be the correct term. 

Length is not a problem in itself.  Lots of these bikes had high rise handlebars put on and we used 10"+ over stock length cables. If the cable is good shape it works fine.

Age is, regardless of length. OF course you can have wear from use, but also get a funny feeling from a cable that's just been neglected. They can rust up inside and give poor feel.

Many shorter cables like from CB350s and CB450s work. If the shop has them, you can lay one up against your cable and see if the fittings and cable play are similar. I'm pretty sure i've used CB350 twin cables with low bars on CB750.

Custom cables can be made by Motion Pro I think and others I'm sure.

[IainC]

I think my best bet then would be to spray some lubricant through the cable again, and measure and get a couple (always best to have an extra) new cables made and ordered to fit.

Hopefully this is my only problem.

[MCRider]

I think my best bet then would be to spray some lubricant through the cable again, and measure and get a couple (always best to have an extra) new cables made and ordered to fit.

Hopefully this is my only problem.

Lubricant can't hurt surely. But expereince teaches if its an old cable, it may not respond. Also, an old cable that feels good with no load on it is a different cable with a load on it.

New custom cables, that's the ticket!

[BobbyR]

I think my best bet then would be to spray some lubricant through the cable again, and measure and get a couple (always best to have an extra) new cables made and ordered to fit.

Hopefully this is my only problem.

Lubricant can't hurt surely. But expereince teaches if its an old cable, it may not respond. Also, an old cable that feels good with no load on it is a different cable with a load on it.

New custom cables, that's the ticket!

I bought my new cables from Honda for 78 750K a few more dollars than Motion Pro, but maybe worth it long term.

[IainC]

Happened again to me on the way home from work. Was stuck in maybe 5-10min of stop and go traffic, and as I was accelerating when it cleared up I started losing power, and shifting into second and third gear seemed to really bog it down. I pulled over and at this point it would not shift at all, pulling in the clutch lever did nothing, and it would not shift into neutral. I decided to go for a walk to the coffee shop down the street by the time I got back it still wouldn't work but I could get into neutral. I adjusted the nut and screw on the clutch again, made sure my cable was adjusted fine, but to no avail. Eventually I put it in neutral, started her up, and shifted into first and took off, then all of a sudden it was working again.

I'm getting frustrated and worried this might be worse than just an old cable.

[V4 Lover]

Okay, so this is the second time today this has happened. Now it was as I was cruising on the highway. The bike will get stuck in gear and I'm unable to shift. It can't just be a matter of the cable. The bike is parked now and the lever is just loose, and I can freely shift through the gears. It's almost as if the clutch is getting stuck either engaged or disengaged.

Right now I'm at my buddies place, but I bet if I go out there now that its cooled down, put it in first and drive, it will free up and let it shift again. 

[IainC]

^ That was me, just didn't realize I was logged into Brandon's account.

Tomorrow I head back out with all the clutch parts off my parts bike and see if we can fix it so I can get it home. No luck getting the clutch to engage, its stuck disengaged and I can flip through gears freely. 

[IainC]

REPOST OF WHAT IS ALREADY IN MY PROJECT LOG - FEEL FREE TO POST THERE INSTEAD, THANKS

Today we tore the clutch apart.



After getting the oil drained the first step was to remove the clutch cover. Once off we have 4 nuts to back out. I went around doing this in 4-5 passes on each screw letting the tension on the springs off evenly.



Once off our first problem was evident. The lock nut holding the clutch basket in had worked its way lose and the clutch basket was moving back and forth freely.



It's not the easiest to see, but our second major problem was the clutch plates were really worn down. See how the clutch on the left has little groves running along the plates, notice the one of the right dosn't.



I have an extra lock nut in better shape so we reassembled using this one and the extra clutch basket. Everything else seemed to check out fine.

So once the bike was back together and full of oil again it was time to see if the clutch was working. Low and behold its still stuck!!  What's going on here? It's easy to find neutral and push the bike around. Pulling in the clutch lever actuates the arm fine, but the clutch refuses to disengage. We took it to the top of a small hill and by getting a push start can power shift into first and then ride around, power shifting through the first couple gears, but pulling the clutch lever isn't doing a thing for us.

Could we have tightened the lock nut down too tight? Would this prevent the clutch from operating properly? Is it possible we are just missing something completely obvious? Maybe the plates are just stuck together and disassembling them and getting a good coat of oil will free everything up.

[wookie]

triple check your adjustment at the basket.  The lever can move the arm without disengaging the clutch.   Is there a lot of tension on the lever?

[IainC]

The lever feels fine, not to much tension as its sitting right now. The mechanism is adjusted as per the manual: Loosen lock nut, screw adjusting screw until feeling slight resistance, then backed out 3/4 of a turn, finally tighten back the lock nut making sure not to move the screw.

[wookie]

there should be around 1/2 to 3/4 inch freeplay at the handle before the tension starts.

The 750 is screw into until resistance and back out a 1/4 turn.

I have a feeling it's not adjusted properly at the basket, try overadjusting it in until it disengages the clutch 

[MCRider]

there should be around 1/2 to 3/4 inch freeplay at the handle before the tension starts.

The 750 is screw into until resistance and back out a 1/4 turn.

I have a feeling it's not adjusted properly at the basket, try overadjusting it in until it disengages the clutch 

Yeah 3/4 turn at the basket sounds like a lot.

[IainC]

I adjusted as instructed but can always try it turned out less. Does this mechanism wear over time? My freeplay on the lever feels fine.

Just to clarify, this adjustment is on the little screw hiding underneath the small cap in the middle of the clutch cover.

Thanks for your input

[MCRider]

I adjusted as instructed but can always try it turned out less. Does this mechanism wear over time? My freeplay on the lever feels fine.

Just to clarify, this adjustment is on the little screw hiding underneath the small cap in the middle of the clutch cover.

Thanks for your input

YEs I looked on a CB650 fishy as I'm not a 650 guy, but that is it, rt side cover with a slotted screw on cap. Adjuster screw hides behind that.

[IainC]

You got it. That will be my first thing to try before taking everything apart again to make sure my plates arn't sticking and do a second inspection of all the parts.

[MCRider]

You got it. That will be my first thing to try before taking everything apart again to make sure my plates arn't sticking and do a second inspection of all the parts.

Yeah run it in as described, but only back it out a teenie bit like 1/4 turn.

To your question, they can wear, but on the 750, I've never seen one wear to the point it wasn't serviceable. Yours has a different design but still I can't imagine wear is a problem.

[Bill/BentON Racing]

I just read your posts.Try what MCRider said,good chance it'll work.Bill

[MCRider]

CBCafe brought it up first. So if it doesn't work, blame him. 

[IainC]

Good point, when I break something I know who to blame and I'll make sure I don't accidentally send you the bill MCR 

[bear]

Don't know a lot about the 650's, but it sounds like your plates are binding on the basket.
This can be caused by a worn or failed bearing/bush, or excessive wear on the fingers of the basket.

Cheers,
Brian

[wookie]

CBCafe brought it up first. So if it doesn't work, blame him. 

That's right, blame Canada.  Ha Ha. 
I just did my clutch and when i was adjusting at the basket it felt like i was feeling resistance right away but i had to dial the screw in further for the clutch to disengage.  It's like there were two points of resistance
I'm not an expert but i have gone through the teardown and complete rebuild of my bike and the teething process was long.

hope you get it.

[IainC]

Tore the clutch down again, turns out we installed a piece on the wrong side of the basket so upon fixing this it seems to be working now. Only problem I have is I seem to have stretched my cable too much as we can't adjust it perfectly. I'm at the end of both of the adjusters and no more to go. The clutch is still grabbing just a little with the lever all the way in. Either way it was fixed enough to get home so once I install a new cable hopefully it will be working tip-top. I'm going to avoid driving it so I don't burn out my clutch plates like last time.