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Author Topic: The clutch has left the building! FOUND HIM!  (Read 340 times)

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Offline Dolomite

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The clutch has left the building! FOUND HIM!
« on: September 17, 2019, 01:07:59 pm »
Well the clutch went leaving work yesterday. Luckily I only had a short ride home stuck in 1st @ 6000rpm to get it rolling. Looking at doing either the cyclex Super Clutch Kit or their 4 friction clutch kit. Has anyone used either of these, or perhaps both? Is one longer lasting than the other. Bike is a 1978 CB750K with a 76 cb750K motor with 836 kit, cx1 cam, and PD carbs. Thanks!
« Last Edit: September 20, 2019, 03:54:32 pm by Dolomite »

Offline ekpent

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Re: The clutch has left the building!
« Reply #1 on: September 17, 2019, 04:43:49 pm »
 Usually when a clutch goes bad it slips especially in the higher gears at higher rpm's. What were your symptoms ? 76K clutch has a little different clutch pack then the earlier years.

Offline Dolomite

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Re: The clutch has left the building!
« Reply #2 on: September 17, 2019, 05:28:34 pm »
Loss of power, high rpm to get movement, then it got stuck in first. I know the clutch has gone and it's time to replace it. Was more so looking for any insight on the cyclex clutch kits.

Offline 754

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Re: The clutch has left the building!
« Reply #3 on: September 18, 2019, 12:04:15 am »
 I bet an ear broke off the 4 corner plate with bearing in the middle..
 happened to me,  coming home from a party , all of a sudden any throttle and it would slip.
 bet that's what it is..
Maker of the WELDLESS 750 Frame Kit
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My next bike will be a ..ANFOB.....

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73 836cc.. Green, had it for 3 decades!!
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Offline 70CB750

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Re: The clutch has left the building!
« Reply #4 on: September 18, 2019, 03:41:10 am »
I bet an ear broke off the 4 corner plate with bearing in the middle..
 happened to me,  coming home from a party , all of a sudden any throttle and it would slip.
 bet that's what it is..

Interesting.  When I took Dorothy apart, one corner was missing but the clutch never stopped working.

Offline Borth42

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Re: The clutch has left the building!
« Reply #5 on: September 18, 2019, 07:29:05 am »
Twice now since I have had my cb650, I switched to 5th gear and my bike did not go into gear.
It was like I shifted into neutral, but without being in neutral.

I am glad I stopped in on this thread, wonder if I have some work to do now..

Offline Dolomite

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Re: The clutch has left the building!
« Reply #6 on: September 18, 2019, 07:59:32 am »
I bet an ear broke off the 4 corner plate with bearing in the middle..
 happened to me,  coming home from a party , all of a sudden any throttle and it would slip.
 bet that's what it is..

Is there something else I will need in addition to steels and frictions then? Haven't opened it up yet to take a look, waiting on the clutch tool to get delivered tomorrow.

Offline 754

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Re: The clutch has left the building!
« Reply #7 on: September 18, 2019, 09:36:45 am »
pop the outer cover off and see if the plate broke.. .
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline ekpent

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Re: The clutch has left the building!
« Reply #8 on: September 18, 2019, 10:09:34 am »
 Does the bike still shift even without the clutch while sitting stationary with the engine off ?  You should be able to row through the gears,may have to rock it back and forth a bit.

Offline Dolomite

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Re: The clutch has left the building!
« Reply #9 on: September 18, 2019, 10:49:53 am »
pop the outer cover off and see if the plate broke.. .

Will do that when I get home from work. Are you referring to the assembly cover or the lifter plate?

Does the bike still shift even without the clutch while sitting stationary with the engine off ?  You should be able to row through the gears,may have to rock it back and forth a bit.

It will not come out of first right now, no matter what I do. Shift lever will go down but not up, really hoping it didn't bend a fork, hoping if a corner broke off, as Frank suggested, its just wedging somewhere causing the basket to not move or blocking the forks.

Offline ekpent

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Re: The clutch has left the building!
« Reply #10 on: September 18, 2019, 11:14:55 am »
 The shifting mechanism is on the other side of the engine and the shift forks are buried inside the lower cases hiding in between gear clusters. Best to get in there for some troubleshooting before ordering too many new parts. Being totally stuck in first may be a sign of something else. You mentioned the engine had a loss of power also,that should not really be related to a bad clutch.

Offline Dolomite

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Re: The clutch has left the building!
« Reply #11 on: September 18, 2019, 12:48:46 pm »
The shifting mechanism is on the other side of the engine and the shift forks are buried inside the lower cases hiding in between gear clusters. Best to get in there for some troubleshooting before ordering too many new parts. Being totally stuck in first may be a sign of something else. You mentioned the engine had a loss of power also,that should not really be related to a bad clutch.

The engine had plenty of power, it was a loss of transferring the power to the wheels.

Offline Dolomite

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Re: The clutch has left the building!
« Reply #12 on: September 19, 2019, 01:35:36 pm »
Sorry for the lack of updates. Been a busy week at work and waiting for the clutch tool still. Possibly tomorrow, likely Saturday I'll dig into it and see who was right!

Offline Dolomite

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Re: The clutch has left the building! FOUND HIM!
« Reply #13 on: September 20, 2019, 03:57:12 pm »
Found the little bas.......guy. removed the clutch basket, lifter plate had 2 corners broken off, looks to be an old break no parts found. Is it okay to leave it like that? Clutch pack measured 1.37 which by any standard is toooo thin so thats gonna get replaced. Then for the stuck shift lever. Looks like the gearshift positive stopper spring came off and unwound. Not sure if the bolt backed out or the spring was just already tired and jumped off. Now to get the part numbers and replace.

Offline ekpent

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Re: The clutch has left the building! FOUND HIM!
« Reply #14 on: September 20, 2019, 09:03:04 pm »
 Sounds like you found a 'twofer'.Try an add in the wanted for a lifter plate.

Offline PeWe

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Re: The clutch has left the building! FOUND HIM!
« Reply #15 on: September 21, 2019, 02:17:47 am »
Nos lifter plate not expensive.
CB750 K6-76 1005cc JMR Billet block.
CB750 K2-75 Parts assembled to stock K2

 

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