Author Topic: Clutch Plates Not Flush  (Read 1023 times)

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Offline Ellz10

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Clutch Plates Not Flush
« on: March 13, 2022, 03:45:28 PM »
Straight to the point. I've got a '77 K7, Barnett special clutch kit with steels and frictions without a dual-spring plate. I measured by placing the old OEM clutch right next to the new Barnett one and it's exactly the same stack height. So I went ahead and installed the new clutch and as you can see in the picture, it's exactly 2mm set in.

Now I've heard different opinions, one being that the K7 and K8 had clutches like this and it's normal. Is that ACTUALLY the case or do I need to go back in and throw another plate in? I used ALL the plates that came in the set and like I said, this new set is the exact same height as the stock oem one I removed.

Thoughts?
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'77 K7 - http://forums.sohc4.net/index.php/topic,193043.msg2251436/topicseen.html#new

Offline Don R

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Re: Clutch Plates Not Flush
« Reply #1 on: March 13, 2022, 04:28:53 PM »
 I asked a similar question in the high performance thread. The 77K parts fische looks just like the 77F parts diagram.
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Offline Ellz10

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Re: Clutch Plates Not Flush
« Reply #2 on: March 13, 2022, 04:49:56 PM »
I asked a similar question in the high performance thread. The 77K parts fische looks just like the 77F parts diagram.

Oh? Is it standard for the 77/78F models to be 2mm set in like this too?
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'77 K7 - http://forums.sohc4.net/index.php/topic,193043.msg2251436/topicseen.html#new

Offline Don R

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Re: Clutch Plates Not Flush
« Reply #3 on: March 13, 2022, 09:13:33 PM »
 I believe when you add the springs and the clutch lifter the clutch pack will pull up tight. Be sure the clutch center and hub have the splines lined up, there are two ways they fit and two ways they don't. I think that's how a lot of the lifter plates get broken. The other way is not tightening the bolts evenly in a criss/cross pattern.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline PeWe

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Re: Clutch Plates Not Flush
« Reply #4 on: March 13, 2022, 11:49:14 PM »
My late clutch pack look similar.
I measured the stack height.
38.8mm.
Fresh glass beaded stock metal discs. Double disc grinded, not glass beaded since the small glass media can leave residues.

The photo of it mounted is before all 4 M6 were tightened.
EBC clutch, Barnett 66 lb springs.


When installing F2 clutch  Jan 2020


When installing fresh glass beaded discs Jan 2022
« Last Edit: March 14, 2022, 12:13:57 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Ellz10

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Re: Clutch Plates Not Flush
« Reply #5 on: March 14, 2022, 08:08:34 AM »
I believe when you add the springs and the clutch lifter the clutch pack will pull up tight. Be sure the clutch center and hub have the splines lined up, there are two ways they fit and two ways they don't. I think that's how a lot of the lifter plates get broken. The other way is not tightening the bolts evenly in a criss/cross pattern.

I'm having a hard time understanding what you mean by making sure the clutch center and hub have the splines lined up. Could you explain it a little better? What splines are you talking about? Can you show me on a picture?

Edit:  I believe I know what you're referring to. Do you mean the pressure plate that goes on top after the plates are all installed? The one where if it doesn't set in, then you rotate it 90° and it sets in?

If this is what you are referring to then yes, I made sure its correct!  (:

If you are referring to something else, please let me know.

My late clutch pack look similar.
I measured the stack height.
38.8mm.
Fresh glass beaded stock metal discs. Double disc grinded, not glass beaded since the small glass media can leave residues.

The photo of it mounted is before all 4 M6 were tightened.
EBC clutch, Barnett 66 lb springs.


When installing F2 clutch  Jan 2020


When installing fresh glass beaded discs Jan 2022


Perfect! This is quite reassuring. I went back to Barnett's site to look and it is accurate and the right set for my bike so I was just curious. I'm guessing a few of the F models and the 77/78K's share a few things.
« Last Edit: March 14, 2022, 08:38:18 AM by Ellz10 »
Thankful for everyone on this forum. Grateful to continue to learn so much.



'77 K7 - http://forums.sohc4.net/index.php/topic,193043.msg2251436/topicseen.html#new

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Clutch Plates Not Flush
« Reply #6 on: March 14, 2022, 08:26:54 AM »
Rotate the guts one more tooth and see if it will inset more.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline PeWe

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Re: Clutch Plates Not Flush
« Reply #7 on: March 14, 2022, 10:28:14 AM »
It has 2 positions were the splines match. If wrong, rotate one step as mentioned.

I mark a tower and where it sits with a marker pen to ensure it will sit correct  before adding all discs.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Ellz10

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Re: Clutch Plates Not Flush
« Reply #8 on: March 14, 2022, 10:32:45 AM »
It has 2 positions were the splines match. If wrong, rotate one step as mentioned.

I mark a tower and where it sits with a marker pen to ensure it will sit correct  before adding all discs.

I edited my previous post to ask if I was assuming correctly. After reading your post, I do believe I'm on the same page.
Thankful for everyone on this forum. Grateful to continue to learn so much.



'77 K7 - http://forums.sohc4.net/index.php/topic,193043.msg2251436/topicseen.html#new

Offline PeWe

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Re: Clutch Plates Not Flush
« Reply #9 on: March 14, 2022, 12:22:38 PM »
I believe when you add the springs and the clutch lifter the clutch pack will pull up tight. Be sure the clutch center and hub have the splines lined up, there are two ways they fit and two ways they don't. I think that's how a lot of the lifter plates get broken. The other way is not tightening the bolts evenly in a criss/cross pattern.

I'm having a hard time understanding what you mean by making sure the clutch center and hub have the splines lined up. Could you explain it a little better? What splines are you talking about? Can you show me on a picture?

Edit:  I believe I know what you're referring to. Do you mean the pressure plate that goes on top after the plates are all installed? The one where if it doesn't set in, then you rotate it 90° and it sets in?

If this is what you are referring to then yes, I made sure its correct!  (:

If you are referring to something else, please let me know.

My late clutch pack look similar.
I measured the stack height.
38.8mm.
Fresh glass beaded stock metal discs. Double disc grinded, not glass beaded since the small glass media can leave residues.

The photo of it mounted is before all 4 M6 were tightened.
EBC clutch, Barnett 66 lb springs.


When installing F2 clutch  Jan 2020


When installing fresh glass beaded discs Jan 2022


Perfect! This is quite reassuring. I went back to Barnett's site to look and it is accurate and the right set for my bike so I was just curious. I'm guessing a few of the F models and the 77/78K's share a few things.
One thing about my clutch pack of 38.8mm. The EBC  discs have done at least 25.000 km.
Mostly around 90whp, since end of 2020 +100whp. 1000cc give a clutch pounding torque from rather low rpm.

A new set will probably add a little.  7 discs, 14 sides.....

Maybe time for an extra set on the shelf to be used when urgently needed. ;)
« Last Edit: March 14, 2022, 12:29:17 PM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Ellz10

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Re: Clutch Plates Not Flush
« Reply #10 on: March 14, 2022, 12:36:07 PM »
I believe when you add the springs and the clutch lifter the clutch pack will pull up tight. Be sure the clutch center and hub have the splines lined up, there are two ways they fit and two ways they don't. I think that's how a lot of the lifter plates get broken. The other way is not tightening the bolts evenly in a criss/cross pattern.

I'm having a hard time understanding what you mean by making sure the clutch center and hub have the splines lined up. Could you explain it a little better? What splines are you talking about? Can you show me on a picture?

Edit:  I believe I know what you're referring to. Do you mean the pressure plate that goes on top after the plates are all installed? The one where if it doesn't set in, then you rotate it 90° and it sets in?

If this is what you are referring to then yes, I made sure its correct!  (:

If you are referring to something else, please let me know.

My late clutch pack look similar.
I measured the stack height.
38.8mm.
Fresh glass beaded stock metal discs. Double disc grinded, not glass beaded since the small glass media can leave residues.

The photo of it mounted is before all 4 M6 were tightened.
EBC clutch, Barnett 66 lb springs.


When installing F2 clutch  Jan 2020


When installing fresh glass beaded discs Jan 2022


Perfect! This is quite reassuring. I went back to Barnett's site to look and it is accurate and the right set for my bike so I was just curious. I'm guessing a few of the F models and the 77/78K's share a few things.
One thing about my clutch pack of 38.8mm. The EBC  discs have done at least 25.000 km.
Mostly around 90whp, since end of 2020 +100whp. 1000cc give a clutch pounding torque from rather low rpm.

A new set will probably add a little.  7 discs, 14 sides.....

Maybe time for an extra set on the shelf to be used when urgently needed. ;)

Hah, I have always been a strong proponent of keeping an extra/backup. It's never steered me wrong!
Thankful for everyone on this forum. Grateful to continue to learn so much.



'77 K7 - http://forums.sohc4.net/index.php/topic,193043.msg2251436/topicseen.html#new

Offline Kelly E

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Re: Clutch Plates Not Flush
« Reply #11 on: March 18, 2022, 03:33:54 PM »
Did you stack all of the steels correctly? When they stamp them out it creates a slight dish shape. There's a round edge and a sharp edge. You have to stack them in all the same, it doesn't which way but all the same.
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Offline Don R

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Re: Clutch Plates Not Flush
« Reply #12 on: March 18, 2022, 05:13:26 PM »
Cyclex says the early clutch pack measures 1.460" or 37.08mm and the late one is 1.560" or 39.624mm That might muddy up the waters a bit.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Ellz10

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Re: Clutch Plates Not Flush
« Reply #13 on: March 18, 2022, 05:27:37 PM »
Did you stack all of the steels correctly? When they stamp them out it creates a slight dish shape. There's a round edge and a sharp edge. You have to stack them in all the same, it doesn't which way but all the same.

I was careful to inspect each and do so, yes!

Cyclex says the early clutch pack measures 1.460" or 37.08mm and the late one is 1.560" or 39.624mm That might muddy up the waters a bit.

For Barnett or OEM?
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Offline Don R

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Re: Clutch Plates Not Flush
« Reply #14 on: March 18, 2022, 06:31:08 PM »
http://www.cyclexchange.net/Engine%20Parts%20Clutches.htm

 Scroll down to where it shows the 5 plate system on the right side of the page, there are 4 photos, 2 of him measuring the stack and showing the difference between early and late parts. 
 He's illustrating how to tell early from late clutches so you can order the correct one of his units. The information is still correct.

  My thought is, if whatever is in there can be compressed by the springs and the adjuster can lift the lifter and separate the clutch, it works.
  CycleX is selling all kinds of combinations that still work.
« Last Edit: March 18, 2022, 06:42:31 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline PeWe

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Re: Clutch Plates Not Flush
« Reply #15 on: March 19, 2022, 10:18:01 AM »
I have also seen the clutch pack numbers CycleX has about the standard clutch packages.
Early (6 metal + 7 fibers) and later ( 5 metal + 1 double riveted metal disc + 7 fibers.

I measured other plates I have. Fresh glass beaded I measured before to ensure they were equal and OK.  Double riveted not glass beaded, grinded.

A lower priced Cruzinimage clutch for K6-F3. Fibers are new, have never been soaked in oil
The entire package 39.4mm

I have ordered 2 sets of EBC CK1145 fibers. Good to have in stock ;) I'll measure with those later on. That will indicate how worn my clutch is in my K6.

If each clutch fiber is worn 0.1mm on each side makes 1.4 mm total thickness of the stack height. 7 discs, 2 sides.
(Minus the 2 sides to aluminium where wear might be less, 1.2mm)

I bought an old K2 clutch before that had an extra metal disc in the bottom against the alu. Looked like it has been used like that for a long time.
7 metals + 7 fibers


« Last Edit: March 19, 2022, 11:09:11 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967