Author Topic: cb750k3 clutch adjustment help  (Read 6464 times)

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Offline 5thofhonda

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cb750k3 clutch adjustment help
« on: June 30, 2015, 06:02:20 PM »
Just got done replacing the pads and springs.  I go to adjust the clutch and after a while of messing with it, I still can't feel any resistance at the lever.  What am I doing wrong?

Offline martin99

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Re: cb750k3 clutch adjustment help
« Reply #1 on: June 30, 2015, 11:12:47 PM »
Assuming your cable hasn't snapped... ::)

Slacken off completely the adjustment at both ends of the cable, so the cable is not under any tension.
Loosen the locknut under the clutch cover. Turn the adjusting screw out a turn or two(so it is free), then turn back in clockwise until you can just feel the pressure of it getting tighter. Back it off 1/4 turn, and holding it in position tighten the locknut.
From the clutch cover end, take up the adjustment on the cable until you have about 3/8" to 1/2" freeplay at the lever - meaning you can pull the lever in by that amount before any resistance is felt.
Job done. Use the adjuster at the lever for fine tuning if needed.

If it won't adjust, then the problem is to do with the new parts and/or the way you fitted them. Try the above  first, if no go we'll need a little more information - brands used, stack height, etc. Pics are always good :)
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline PeWe

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Re: cb750k3 clutch adjustment help
« Reply #2 on: July 01, 2015, 03:24:41 AM »
I had a problem with my clucth that felt as a snapped wire. It was the clutch lever inside the clutch cover that came loose when the lock nut was not tightened.
Later on more problem that ended up in removing the entire clutch cover fastened with 10 M6 screws. Removed everything and put it together again. The center screw had seized, not possible to adjsut or remove at all.  item 8 in item 6
http://www.cmsnl.com/honda-cb750k6-four-european-direct-sales_model14384/partslist/E08.html#results

I'm lucky to know one CB750 collector not fa away that have a lot of parts in his garage I can visit when its emergency...
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 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #3 on: July 01, 2015, 04:30:53 AM »
Looks like I'll need to pick up a smaller screwdriver.  The screw is starting to sink into the lock nut.  I replaced the pads with the EBC kit from cycle one, along with new Barnett springs.  Haven't touched anything else.  Cable hasn't snapped either.

Offline mystic_1

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Re: cb750k3 clutch adjustment help
« Reply #4 on: July 01, 2015, 05:10:15 AM »
When the cable adjusters are backed off, the clutch should be in the "engaged" state, verify that first by putting the bike into first gear and seeing if you can spin the rear wheel.  If the wheel can spin freely, you've made a clutch assembly error.

One of the more common problems I see when people are having trouble reassembling the clutch on a CB750 is misalignment of the splines of the pressure plate and the clutch center.  It is not obvious by looking at them but, there are four ways to put them together depending on how they are rotated, and only one or two will work properly.  It's easy to see when the parts are disassembled and on the bench.

This is how the pieces fit together:



Normally their respective splines mesh like this:



BUT you will find that if you rotate the clutch center by 90 degrees, the splines no longer line up properly:



Now, I don't know that this problem would cause your particular symptom, usually it's the opposite, the clutch won't grip because the pressure plate can't clamp down onto the plates:



Once you've found the orientation that works, mark one of the spring posts for future reference.  Magic marker for temporary marking, or dimple it with a center punch for permanent reference.




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My build thread:  http://forums.sohc4.net/index.php?topic=68952.0

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #5 on: July 01, 2015, 07:09:48 AM »
I assume that would mean I'd need to order another gasket if this is the case?

I'm pretty sure the plates are meshed properly because I rotated the basket until it sank all the way into the case. I'll see if I can roll it when I get home.

Offline ekpent

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Re: cb750k3 clutch adjustment help
« Reply #6 on: July 01, 2015, 07:15:03 AM »
  Did you put a new gasket in the first time ? Unless you used some type of glue etc. you can usually re-use them on side covers.

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #7 on: July 01, 2015, 09:34:26 AM »
New gasket with threebond sealer.

Offline martin99

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Re: cb750k3 clutch adjustment help
« Reply #8 on: July 01, 2015, 12:54:42 PM »
Looks like I'll need to pick up a smaller screwdriver.  The screw is starting to sink into the lock nut.  I replaced the pads with the EBC kit from cycle one, along with new Barnett springs.  Haven't touched anything else.  Cable hasn't snapped either.

IIRC there is a piece that the adjuster bears upon that fits into the bearing in the lifter plate. I'm thinking that if that is missing the adjuster will just continue on through the bearing centre? That's if I understand its operation correctly anyway. #7 in the schematic-

http://www.cmsnl.com/honda-cb750-four-k5-usa_model483/partslist/E++09.html#results
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #9 on: July 01, 2015, 02:31:35 PM »
Just got home. The bike will NOT roll in gear, so we're good there. But tut seems no matter how I adjust it. There's still no resistance at the lever.

Offline PeWe

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Re: cb750k3 clutch adjustment help
« Reply #10 on: July 01, 2015, 02:53:04 PM »
I have no sealer on my gasket. I have removed a nd reassmbled the cover twice without any leaks. Careful when removing cover to not brake gasket if stuck on both sides but different locations.
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 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #11 on: July 01, 2015, 03:00:40 PM »
The adjuster and lock nut are correct (I think) but there is still play in the throw out.

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #12 on: July 01, 2015, 03:19:53 PM »

No resistance at all, at any adjustment.  Like it isn't connecting with whatever is behind it
« Last Edit: July 01, 2015, 03:31:47 PM by 5thofhonda »

Offline martin99

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Re: cb750k3 clutch adjustment help
« Reply #13 on: July 01, 2015, 03:38:48 PM »
The locknut needs to be a lot further up the threads than you have it in your video. On mine, and others I've done, the locknut tightens almost flush with the top of the adjuster. Yours looks like it can go in at least another 1/4"- 3/8" before you would expect to feel pressure. If you still have no contact after that, I'd think about what I suggested in my previous post.
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #14 on: July 01, 2015, 04:34:03 PM »
Decided to trash the gasket and figure this out.  The throwout isn't engaging itself when it's turned.  The back plate pushes out so there's no actual pressure being applied to the actuator.  All parts are there and in the correct place(s).

Offline mystic_1

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Re: cb750k3 clutch adjustment help
« Reply #15 on: July 01, 2015, 04:39:57 PM »
I'm not following your explanation.  Might help if we used common terminology for the parts, as per the workshop manual.



Got a video, perhaps?
« Last Edit: July 01, 2015, 04:42:26 PM by mystic_1 »
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Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #16 on: July 01, 2015, 04:59:10 PM »
Apologies.  The clutch release shaft and bearing retainer components are not working properly with the lifter cam when rotating.

Offline Vinhead1957

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Re: cb750k3 clutch adjustment help
« Reply #17 on: July 01, 2015, 05:10:43 PM »
 So what someone suggested was check item 12 to see if it got lost in reassembly

Offline mystic_1

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Re: cb750k3 clutch adjustment help
« Reply #18 on: July 01, 2015, 05:20:23 PM »
In what way are they not working properly?

With the cover off, apply pressure to the end of the clutch adjusting bolt from the inside, so that you're pushing the lifter assembly against the cover.  Now rotate the clutch release shaft, like the clutch lever would when you pull the cable.  The ball bearings in the ball retainer should ride up in the ramps on the clutch release shaft and the clutch lifter cam, pushing the whole assembly away from the cover, towards the inside of the engine.

In your video above, the clutch release shaft is moving inwards far enough that hte balls in the ball retainer are riding right up out of the ramps entirely.  Apply pressure from the inside and rotate until the balls fall back into their recesses, and then check as described above.


Since you have the clutch open again, I'd go ahead and verify the Clutch Lifter Piece is in place, and consider popping the plates out again and checking for spline alignment on the clutch pressure plate versus the clutch center as per my earlier post.

mystic_1
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Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #19 on: July 01, 2015, 05:21:17 PM »
To which I replied that it had not.  Parts 6 and 9 do not stay meshed together.  They expand as they should, but do not retract.  Instead they spin free, which creates the lack of resistance.  My issue now is that I have no idea how to get them to stay put.

I turned the bike on and shifted into first.  The bike wouldn't roll, but otherwise acted as though the clutch was engaged.  It didn't stall, and adding throttle had no effect either.

Offline mystic_1

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Re: cb750k3 clutch adjustment help
« Reply #20 on: July 01, 2015, 05:33:50 PM »
What you describe regarding the lifter components sounds normal, I do not believe your problem is with the lifter components.  Ordinarily these parts can only rotate a few degrees, if they rotate too far then the balls ride right up out of the ramps and sit between the lifter cam and the release shaft's plate.

Rotation is normally limited by the end of the adjusting bolt bearing against the lifter piece in the center of lifter plate, which is under spring pressure from the clutch springs.

It's sounding more and more likely to me that spline alignment is your problem.  When it is incorrect, the lifter plate cannot move "outward" far enough, creating the gap you're noticing between the lifter piece and the adjusting bolt.

You also describe being able to put the bike into gear, with the engine running, and NOT having the rear wheel spin.  This suggests the clutch is DISENGAGED and spinning freely.  Ordinarily you pull the clutch lever which DISENGAGES the clutch, and release the lever to ENGAGE the clutch.  From your description the plates are not grabbing down on one another, so disengaged, which is a symptom of the spline alignment problem. 

I would suggest you mark the orientation of the parts, pull out the clutch center, plates, and pressure plate, and check your spline alignment as per the photos above.

mystic_1
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Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #21 on: July 01, 2015, 06:42:58 PM »
I was hoping that wasn't the case but I'll give that a shot tomorrow after work.  And now because of the holiday weekend, my new gasket won't get here until Monday, even though I'm 3 hours from Cycle One.

So far the only bright side is that I figured out my electronic ignition actually works.  Previous owner said it was temperamental, but didn't know why.  It's a little loose and doesn't always connect, but with my new tail light, it's easy to tell when it hits.  No more kicking for me unless I want to be cool.

Offline Vinhead1957

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Re: cb750k3 clutch adjustment help
« Reply #22 on: July 01, 2015, 06:50:19 PM »
Kicking saves the starter! And if you are running good one kick is all you need

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #23 on: July 01, 2015, 06:57:21 PM »
Once it's warm, it only takes one.  I'm not too worried about running good until the motor gets built.  So long as it moves, I'm happy for now.

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #24 on: July 03, 2015, 12:39:19 PM »
This is how the clutch basket looks.  To me it seems like it looks correct when compared to walkthrough pictures.  Can anyone else tell from these?






Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #25 on: July 03, 2015, 01:08:29 PM »
I shouldn't be able to wiggle the pressure plate from the outside, should I?  With it all assembled, I can move it by wiggling the part that the springs surround.

Offline mystic_1

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Re: cb750k3 clutch adjustment help
« Reply #26 on: July 03, 2015, 02:32:47 PM »
Being able to move the pressure plate around by wiggling the springs posts is normal at this stage, what you want to check for is to see whether you can pull the pressure plate outwards enough to squeeze the clutch plates against the lip of the clutch center.  If the spline alignment is wrong, you wont be able to pull the pressure plate outwards enough to do so and the clutch plates will always be loose.  It's not possible to see this in your photos.
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Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #27 on: July 03, 2015, 02:49:52 PM »
I couldn't pull it outwards at all.  I have to wait until the holiday is over to borrow my buddy's impact again to get it apart.

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #28 on: July 07, 2015, 01:59:59 PM »
Well, got it all situated.  Got everything taken out and put back in correctly.


And snapped the lifter plate.

Any idea where to pick one up?  Looks like Honda discontinued them.

Offline Vinhead1957

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Re: cb750k3 clutch adjustment help
« Reply #29 on: July 07, 2015, 02:49:20 PM »
Just google the part# 22360-300-010 are out there $52-$100 range

Offline oldhatt45

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Re: cb750k3 clutch adjustment help
« Reply #30 on: July 07, 2015, 03:46:55 PM »
Check this listing.

CMSNL 45.50 Euro's = $50.03 dollars

http://www.cmsnl.com/products/plate-lifter_22360300010/

Charlie

Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #31 on: July 07, 2015, 03:49:49 PM »
Not bad at all, just a long wait for shipping.

Edit:  Just found a complete basket on ebay and snagged it for $53 shipped
« Last Edit: July 07, 2015, 03:56:45 PM by 5thofhonda »

Offline mystic_1

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Re: cb750k3 clutch adjustment help
« Reply #32 on: July 08, 2015, 05:02:35 AM »
Ouch, I was afraid that would happen.  Breaking the pressure plate is one of the other most common clutch woes on these bikes.  Since you nabbed a complete clutch, compare the "new" basket (outer) to your existing one and see if the slots that the clutch plate tabs ride in is in better shape than yours.  The edges of these slots can sometimes become worn or dinged, resulting in a slightly noisier clutch.  Not always, because the tabs on the friction plates are softer than the material of the outer basket.  Also compare the clutch centers where the teeth of the clutch plates ride in the splines for the same sort of wear.

Also dry-fit the clutch center and clutch outer as per the earlier pictures and mark their orientation, to speed future disassembly/reassembly.

cheers
mystic_1
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Offline 5thofhonda

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Re: cb750k3 clutch adjustment help
« Reply #33 on: July 11, 2015, 08:07:35 PM »
Took the broken lifter plate to a welder.  He said he could weld it, but because of where the break was, he couldn't do it properly and it would probably break as soon as I tightened it down again.  So now we wait for the replacement.