Topic: CB400F Clutch Bearing play?

[Machinegun Mike]

Hi all,  my first post, so be gentile. 

I've done a significant amount of searching regarding my clutch not disengaging fully, and have a few things to try when i get home, thanks to that. i think i either have the wrong oil or too much oil... hopefully nothing worse! :3

I have a question regarding the play in the clutch adjuster.  the vid tells the story. is this excessive play?  if so what is likely to need replacing?
http://youtu.be/tQV5AkOFLDo
bike is stock '75 CB400F.

cheers,
Mike.

[thirsty 1]

there is an eccentric under that thing your fingering. it pushes the plates apart disengaging your clutch. stop breathing so heavy your making me horny. turn in till it touches, turn out 1/4, tightened jam nut, ride. 

 

[Machinegun Mike]

lol

So you don't think the amount of play in it is abnormal?   

I have adjusted the screw as per the manual, like you've suggested and at best i can get it to only slightly creep forward.   I adjusted it in a bunch of different ways all resulting in varying amounts of creep.   

It only started happening when i changed my oil to 15w40 car mineral oil. so i'm fairly confident that is the problem.  I've read that car oils can make the clutch plates stick together, which seems right because if i pull the clutch in and rock the bike back and forth it frees up a bit.

[thirsty 1]

haha,  so if you let the clutch out the bike doesn't move? is it new to you? id capitalize but im lazy typing with one hand. say hi to Brisbane for me.

[thirsty 1]

I think you answered your own question with the oil thing. my clutched slipped.  my clutch was replaced with barnett plates and discs hd springs.  no slippy no more. 

[thirsty 1]

lol

So you don't think the amount of play in it is abnormal?   

I have adjusted the screw as per the manual, like you've suggested and at best i can get it to only slightly creep forward.   I adjusted it in a bunch of different ways all resulting in varying amounts of creep.   

It only started happening when i changed my oil to 15w40 car mineral oil. so i'm fairly confident that is the problem.  I've read that car oils can make the clutch plates stick together, which seems right because if i pull the clutch in and rock the bike back and forth it frees up a bit.

if it leaks oil then its to much. just my 2 cents 

[Machinegun Mike]

Hi Brisbane.   

it'll move. it won't stop.  if i put the clutch in and come to a stop, with my foot on the brake to stop it creeping forward, the engine will stall because the clutch is still slightly engaged.   So it's doing the opposite of slipping.

oil level is currently at the max line on the dipstck...

[thirsty 1]

ask yourself if you've changed anything from late? reverse if you did and check your results. turn that grub out to 1/2 and try that. as you know your clutch wants you to stop riding in the city.  try twisty roads with no stopping. that should do you right

[Machinegun Mike]

I changed the oil, and the valve cover gasket.   i over filled the oil, but pumped it out to the max level on the dipstick before starting it.  Nek minnit, clutch no worky.

[nancy]

Mike
First - put the right oil in. Motorcycle oil with NO anti-slip or whatever properties. Meantime,...have u tried to get the bike running by push/bump starting it? I'd expect the plates to free after a few seconds under load of riding. I have had the exact symptoms on my 750. After a period of downtime - plates were stuck and the bike would stall when I tried to put it in gear. So I fired it up again and pushed it and leapt onboard and put it in 1st while rolling. Was good after that.
Regards
Mark

[thirsty 1]

could be you have plates with goo on them and they don't want to spin free. stuck together. or your clutch disc hub has notches in it where the plates ride not letting the plates move. or you put some sealer on your cover gasket and now its stuck in your clutch plates. I did this to my wifes bike. I did not get laid for a few days. or your clutch cable is wonky and not letting your clutch release. or your going to have to remove your foot rest and kicker and look in there. I don't know which there to use. is it their, there, or they're? drink tooheys old. or ride another bike for awhile and go to the dog races...

[thirsty 1]

or the clutch hub nut has come loose and the whole assm. is loose under the cover. even if you overfilled the oil level it wouldn't cause your clutch to stick. wrong oil yes. its not a big deal to pull the cover. pm me if you need help with it. I don't mind

cheers

[Machinegun Mike]

Mike
First - put the right oil in. Motorcycle oil with NO anti-slip or whatever properties. Meantime,...have u tried to get the bike running by push/bump starting it? I'd expect the plates to free after a few seconds under load of riding. I have had the exact symptoms on my 750. After a period of downtime - plates were stuck and the bike would stall when I tried to put it in gear. So I fired it up again and pushed it and leapt onboard and put it in 1st while rolling. Was good after that.
Regards
Mark

Thanks mark, i will 100% be doing this.  The bike had barely sat a week since the last start. so it's a fair bet the oil is the problem.  I can get the bike off the mark,  it'll run for enough time to give it some revs and take off. however it wont let me select neutral again once it is in gear because the clutch wont release, or any other gear for that matter, bangs into 1st and then i cant lift it back out until the bike stalls, or i turn it off.

would you agree that simply using the wrong oil would cause my symptoms?  everything else i've read suggest that the clutch will slip, rather than not release.

[nancy]

I'd have thought not - as far as I know, wrong oil - with anti-slip additive will just cause slippage. But I am not certain. I would guess a coincidental issue with stuck friction plates, warped steel plates or thrust bearing area. You might just have some stuck disks - maybe this oil was the catalyst that caused that - but I can't explain why. I am suggesting you dump the oil and keep it for your lawnmower or weed whacker. Put in the right oil and if the fault does not go away; pull apart your clutch.

In my case - last year - I had reassembled my clutch during a rebuild that took ages - I had 2 slightly warped steel plates. I swapped them out for better ones and my fault was fixed. However - I have had as I mentioned - the same problem since from leaving my bike idle for about 2 weeks. The bump start fixed it - followed by a loosening up ride and all was well.

Change your oil before any further analysis.

Regards
Mark

[Machinegun Mike]

hmm. good point.

i had noticed a little bit of slipping before i changed the oil.  I put that down to topping up the oil with car oil of the same weight, but with lots of additives, as i was losing a fair bit of oil from the valve cover.   i dropped that oil and put in the 15w40 mineral oil, which seemed to be the purest thing i could find, after fixing the valve cover leak..

[nancy]

I buy ELF brand (French - sorry about that Greenpeace)...see below..20w50 is the correct for the 750. Dunno if your model should be different or not. I had better experience with the bike with 20w50 than when I tried lighter stuff such as 10w or 15w...

http://www4.total.fr/pdf/elf-lubricants/product-guide/index.htm?startPage=38

[Machinegun Mike]

The last paragraph in the article below briefly mentions oil causing dragging

"The most common cause of this problem is a badly adjusted clutch. However, modern oils can sometimes cause this problem."
http://classicmotorcycles.about.com/od/serviceandrepair/ss/Adjusting-And-Inspecting-Motorcycle-Clutches.htm

fingers crossed that's all it is.  damn work getting in the way of me getting some oil!!

[Machinegun Mike]

for the sake of anyone who finds this in a search, i changed the oil to a 10w40 motorcycle oil and the problem is gone!

so incorrect oil can cause drag as well as slip!