Author Topic: Cb750k6 clutch disc query  (Read 2615 times)

Offline Nurse Julie

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Re: Cb750k6 clutch disc query
« Reply #15 on: December 30, 2018, 06:35:54 PM »
Paul, I have just read through all the above, are you certain that the new friction plates you are wanting to fit, are actually for a CB750/4. What I'm saying is, have you ordered / received the correct parts?
Edit...Did you buy this as a kit from David Silver by any chance?
« Last Edit: December 30, 2018, 06:40:27 PM by Nurse Julie »
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Offline Paulreade

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Re: Cb750k6 clutch disc query
« Reply #16 on: December 30, 2018, 09:56:59 PM »
Hi Julie, I purchased the bike from James H and he sent me the parts for the clutch confirming they are the discs for the bike and from David silver spares.
So hopefully all ok.Do you ask for any specific reason ?
Regards
Paul
Current bikes:
Suzuki GSX 1250 FA
Triumph t100 bonneville
Honda cb750 k6

Offline Nurse Julie

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Re: Cb750k6 clutch disc query
« Reply #17 on: December 30, 2018, 10:06:08 PM »
Ah, it's all making more sense to me now. Yes, James did supply you with the correct clutch kit as sold by Silver for a K6. The problem is, maybe it's the wrong clutch for your bike. The kit you really need is from EBC part number CK1145. This kit only has one directional plate. Hope this helps. As you get more used to your bike and the parts, you will realise although David Silver supplies a lot of parts, not all of them are correct, spark plugs come to mind but, that's another story.
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Paulreade

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Re: Cb750k6 clutch disc query
« Reply #18 on: December 31, 2018, 08:46:35 AM »
Yes it's been an interesting debate on both sides of the pond ( usa&uk). The guys in the USA have said exactly the same thing that I should be using the CK 1145 pack not a set with all slanted oil grooves. They are also advocating a double sprung steel disc , I guess to quieten the rattle ?.
Will be taking up with David silver spares in the new year.
Regards
Paul
Current bikes:
Suzuki GSX 1250 FA
Triumph t100 bonneville
Honda cb750 k6

Offline AshimotoK0

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Re: Cb750k6 clutch disc query
« Reply #19 on: December 31, 2018, 09:41:17 AM »
The bulletin they are referring to is from 'Wrench' and its on here buried right near the end of my dropbox mega CB750 file. It refers to using a double clutch plate from the Goldwing and was used in the Cb750K7 clutch

You need to scroll down a looooong way on this but t's there !

https://www.dropbox.com/s/anpzqn2r55f1o9k/CB750%20Mega%20Parts%20Service%20and%20More.pdf?dl=0


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« Last Edit: December 31, 2018, 10:02:23 AM by AshimotoK0 »
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Offline Trigger

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Re: Cb750k6 clutch disc query
« Reply #20 on: December 31, 2018, 09:52:02 AM »
I have just had a look on the USA site and Hondaman is correct about the plates but, there is no need for a double plate on the K6 , all you need is a CK1145 and put the final plate in as i have already advised. I have built a number of theses clutches and if it did not have a double plate fitted then, it was built without it and they worked fine.
I don't think you will get any answers from Sliver, they sell parts that fit but, may not work  :o Over the years i have had many confrontations with them and all i get is " well, the computer says"  >:(   

Offline Paulreade

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Re: Cb750k6 clutch disc query
« Reply #21 on: December 31, 2018, 02:58:55 PM »
Cheers trig, do you buy the ck1145 from silvers or just trawl the web for the best deal ?.
Glad I asked the question though initially, it's been an interesting debate.
P
Current bikes:
Suzuki GSX 1250 FA
Triumph t100 bonneville
Honda cb750 k6

Offline Trigger

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Re: Cb750k6 clutch disc query
« Reply #22 on: December 31, 2018, 05:40:41 PM »
I get them from EBC  ;)

Offline SamCR750

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Re: Cb750k6 clutch disc query
« Reply #23 on: December 31, 2018, 06:24:03 PM »
I can't even find the clutch in my CB750A, hahaha Happy New Year everyone.

Offline Trigger

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Re: Cb750k6 clutch disc query
« Reply #24 on: December 31, 2018, 11:14:01 PM »
I can't even find the clutch in my CB750A, hahaha Happy New Year everyone.

If you get on to Sliver, they will sell you one  ;D ;D

Offline Paulreade

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Re: Cb750k6 clutch disc query
« Reply #25 on: January 01, 2019, 02:55:58 PM »
I might first go down the route that they have sold the wrong one in the first place and ask for an exchange - worth a try
Current bikes:
Suzuki GSX 1250 FA
Triumph t100 bonneville
Honda cb750 k6

Offline Paulreade

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Re: Cb750k6 clutch disc query
« Reply #26 on: January 07, 2019, 05:54:54 PM »
By way of an update: d avid silver spares unfortunately cannot assist on the clutch issue. They appear to supply a clutch set which comprises of all slanted oil grooves with current part numbers appertaining to the k6 bike. They state Honda made the changes to all slanted friction discs away from the 6+1 set ( 6 straight grooves + 1 slanted grove disc ) and that they supply this for the 'k' series bikes and have had no negative feedback to date.
It's tempting to try the discs before I invest in a ck1145 kit but I have yet to make that decision.
What I have checked is that the friction discs are all well within their service limit ( in fact they are hardly worn at all from the standard values. - leading me to suspect the clutch may have already been replaced. It was biting at around 3/4 which led me to think the clutch was at the end of its life ?.
What I have noticed is that the old springs are way over length. The replacement ( new) springs I have are of the standard length but the old ones are approx 3-5 mm longer - again this leads me to suspect the clutch has been out at some point.
I am tempted to replace the springs with the correct ones and clean all the discs and reuse them for a while longer.
Is this sound logic if the discs are all in spec ?
Also what method would be advised to clean the metal plates before rebuilding the clutch ?, is it a case of brake cleaner and a very light touch with wet and dry ??????
Sorry to rake this up again but it has brought out quite a bit of debate.
The outer friction disc on my clutch was fitted with the outer edge of the grooves trailing the inner, I will flip this as per triggers advice and have the inner edge of the groove trailing the outer as per the attached to see what effect this has ?
Regards
Paul
Current bikes:
Suzuki GSX 1250 FA
Triumph t100 bonneville
Honda cb750 k6

Offline Trigger

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Re: Cb750k6 clutch disc query
« Reply #27 on: January 07, 2019, 06:23:05 PM »
If Honda made changes to all slanted plate then why are Sliver doing this kit as 1 oem and 6 aftermarket friction plates  ???.

Clutches can be a little strange and i would not believe the Honda service limits. I have had shed load of clutches slipping and on removal of the plates, they have been with in spec. New friction plates in and everything was working as it should. A plate can be with in spec but, if it is old and brittle it will slip.

There are two different lengths of springs fitted to the 750's. Make sure you have a K6 clutch basket, just because your bike is a K6 it, doesn't mean all the parts are K6 ;) 

Offline Paulreade

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Re: Cb750k6 clutch disc query
« Reply #28 on: January 07, 2019, 07:09:56 PM »
Duly noted trigger, ck1145 required.

Plot thickens as regards the basket query ???. Would it be too much trouble to throw a few pointers to see if I can clarify if it's a k6 basket ?.
It's the first basket I've ever touched - let alone identifying it's type ?.
Is there a specific thing I can check or would you need photos etc ?
Many thanks
Paul
Current bikes:
Suzuki GSX 1250 FA
Triumph t100 bonneville
Honda cb750 k6

Offline Trigger

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Re: Cb750k6 clutch disc query
« Reply #29 on: January 12, 2019, 09:43:17 AM »
I would just fit the CK 1145 and the spring that came out your old clutch basket. The shorter springs can be a bit of a bugger and i think they maybe a supersede part. Check the PN of the springs against the original PN for the K6.

Have not had time to look for a K6 basket and take photo's as yet.

 

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