Topic: CB350F Clutch Not Disengaging

[danfr]

Hey guys, I'm having issues with my CB350F clutch not disengaging.

The bike has never shifted smooth from my first day with it. It was always tolerable but it never felt like it would completely disengage. So yesterday I decided to reattempt to adjust the clutch and now the clutch does not appear to work at all. I have followed the clutch adjusting instructions from the Honda manual to a T and with no luck.

Today I pulled off the clutch cover and found that the steel plates looked to have heavy rust spots on them, so I sanded them down a bit (see pic)

Other than poor adjustment what causes clutches not to fully disengage?

What is the symptom of warped steel plates?

If my plates are not too warped (still in spec), should I glass blast my plates at work?

Thanks

Dan

[HondaMan]

You're looking right at the problem! 

The rust causes clutch drag, big time. If you blast 'em, don't go so far as to remove the little "divots", as they are partly (largely) responsible for holding oil ready for the next disengagement when you pull in the lever. When you release the clutch, the plates squeeze some of the oil out their edges, and trap some in those tiny divots.

On the other hand, the rust prevents the fiber plates from being able to slip past the steel ones easily. When disengaged, these plates only separate by about .008" at the most, so it takes very little to make them drag agin' each other.

Maybe glass bead? Maybe soda blast? I'd be interested in seeing how yours come out, as I have seen a lot of rusty ones lately, and they are otherwise fine. It was the 20 years of sitting with old, wet oil in them that made them rust. 

[kghost]

You're looking right at the problem! 

The rust causes clutch drag, big time. If you blast 'em, don't go so far as to remove the little "divots", as they are partly (largely) responsible for holding oil ready for the next disengagement when you pull in the lever. When you release the clutch, the plates squeeze some of the oil out their edges, and trap some in those tiny divots.

On the other hand, the rust prevents the fiber plates from being able to slip past the steel ones easily. When disengaged, these plates only separate by about .008" at the most, so it takes very little to make them drag agin' each other.

Maybe glass bead? Maybe soda blast? I'd be interested in seeing how yours come out, as I have seen a lot of rusty ones lately, and they are otherwise fine. It was the 20 years of sitting with old, wet oil in them that made them rust. 

I agree Mark.

I've glass beaded them with fine bead material.

Still doesn't explain why it sorta worked and now doesn't.

I think you've screwed something up in the adjustment.

[dave500]

just hand sand or blast those steels clean,going by the rust tell tale id replace those frictions aswell,,youll be doing the work twice otherwise.

[danfr]

hey guys!

Thanks for the replies! I feel so well looked after!

It is possible that I did an improper adjustment, but I do find it unlikely. I tried multiple times verbatim but also tried a few variances with no change. When I first pulled the the clutch apart, there were quite large patches of rust.

I'll glass blast them tomorrow at work with a lower gun pressure. I also picked up a set of friction discs last year. I'll soak them in oil overnight tonight and assemble it all back tomorrow.

fingers crossed!

[danfr]

Ok, so I glass blasted the steel plates and reinstalled them with new friction plates, and no change.

I did notice that the plates did NOT have the perforations like I've seen in some photos of 350F steel plates.

I wouldn't imagine new springs would help as I don't have an issue with a slipping clutch.

Should I consider getting new plates?? A few of them were slightly warped, but nothing past 0.001"

Cheers

[Jasondo]

What type of oil are you running?? This has a profound effect on clutch performance . Oils that do not lubricate properly will not allow the clutch to completely disengage and drag. I am dealing with this very issue right now.

[HondaMan]

Ok, so I glass blasted the steel plates and reinstalled them with new friction plates, and no change.

I did notice that the plates did NOT have the perforations like I've seen in some photos of 350F steel plates.

I wouldn't imagine new springs would help as I don't have an issue with a slipping clutch.

Should I consider getting new plates?? A few of them were slightly warped, but nothing past 0.001"

Cheers

It's entirely possible that some of the rust has gotten stuck to the cork, too. Before replacing the fiber plates, consider (if you're patient) scrubbing it off of the cork with one of those soft metal or brass "detailing brushes" you can get at auto parts stores. They come in sets of 1 steel, 1 brass, and 1 nylon, look like big toothbrushes (good for big dogs...). It might be worth the effort, although it won't fully restore the performance.

[danfr]

Ok, so I glass blasted the steel plates and reinstalled them with new friction plates, and no change.

I did notice that the plates did NOT have the perforations like I've seen in some photos of 350F steel plates.

I wouldn't imagine new springs would help as I don't have an issue with a slipping clutch.

Should I consider getting new plates?? A few of them were slightly warped, but nothing past 0.001"

Cheers

It's entirely possible that some of the rust has gotten stuck to the cork, too. Before replacing the fiber plates, consider (if you're patient) scrubbing it off of the cork with one of those soft metal or brass "detailing brushes" you can get at auto parts stores. They come in sets of 1 steel, 1 brass, and 1 nylon, look like big toothbrushes (good for big dogs...). It might be worth the effort, although it won't fully restore the performance.

I've already replaced the fiber plates, so I'm ASSUMING that the next and hopefully final step would be to replace the slightly worn plates.

I do have superbike bars which do run a little shorter than the stock bars so the clutch cable is a little long. I could be wrong, but I believe the extra slack can be taken out by adjusting the clutch properly.

[HondaMan]

Ok, so I glass blasted the steel plates and reinstalled them with new friction plates, and no change.

I did notice that the plates did NOT have the perforations like I've seen in some photos of 350F steel plates.

I wouldn't imagine new springs would help as I don't have an issue with a slipping clutch.

Should I consider getting new plates?? A few of them were slightly warped, but nothing past 0.001"

Cheers

It's entirely possible that some of the rust has gotten stuck to the cork, too. Before replacing the fiber plates, consider (if you're patient) scrubbing it off of the cork with one of those soft metal or brass "detailing brushes" you can get at auto parts stores. They come in sets of 1 steel, 1 brass, and 1 nylon, look like big toothbrushes (good for big dogs...). It might be worth the effort, although it won't fully restore the performance.

I've already replaced the fiber plates, so I'm ASSUMING that the next and hopefully final step would be to replace the slightly worn plates.

I do have superbike bars which do run a little shorter than the stock bars so the clutch cable is a little long. I could be wrong, but I believe the extra slack can be taken out by adjusting the clutch properly.

You're entirely right about the adjustment. Longer cables are alos longer in the sheath, so the moving length stays the same either way (on a well-made cable, that is...).

[danfr]

I am looking at the specs of my bike and I cannot seem to find the torque spec for tightening down the clutch springs. I'm on page 76 of the service manual and it has the clutch spring preload (42.557-45.643 lbs) and the clutch free length but I have no idea how much I should be torquing down the clutch springs.

any insight would be appreciated!

Dan

[danfr]

Ok, so! New clutch fiber plates, new steel plates, new springs and GN4 Honda 10W-40 and not disengaging at all. I let the bike idle around 2500 to let the oil warm up and it is not working.

There has got to be a factor I am missing or overlooking.

Help!

[danfr]

Mystery solved.



Part number two was backwards. Boy do I feel like a fool. Ah well, off to the beach!