Topic: Clutch help please

[bigring]

Thanks in advance for taking the time to read . . . .

I have a '76 cb750 that I am in the process of rebuilding.  On the clutch now.  PO had the six steel clutch plates and seven fibre friction discs. No B clutch outer ring nor clutch plate stopper ring.  What I've been reading (my manual - Clymer, diagrams of the clutch parts on the web, etc) all seem to conflict in terms of what parts I should have.  I didn't ride the bike so cannot comment how well the clutch worked - the PO was using it as his daily commute up until he stopped riding it. 

Here's what I have:



Also, four of the plates have a number 8 on the fins; and three have a number 7.  What does this mean?

[disco]

Hi Bigring,

There is a lot of info on this site about the CB750 clutches. Suggest you do a search & read up on the various types. There is about 3 different types. I'm still not happy with mine. A word of warning......be very careful with mixing & matching different year parts. My advice would be to try it, before you alter anything. It's not hard to get back in there later if you need to.

I also have a '76 CB750 & appears mine is different to yours. My outer friction plate is the 'slant cut' type with the wider tangs. It will only fit as the last plate installed into the clutch basket. Can you take a pic of your clutch basket? I'm guessing you have old style basket. When I got my bike it also had the double steel (goldwing type) plate installed. I'm guessing this must have been a warranty job? I had to replace my friction plates & don't have the double steel plate installed at present & I'm running 7 frictions & 6 regular steels. I'm not happy with this setup & I'm going to try going back to the "hybrid" double steel setup which from memory runs 6 steels (5 regular & 1 double steel) & 6 frictions.

If that doesn't produce the desired result.....I just purchased the longer K7 clutch hub which I will then try with 6 steels (5 regular & 1 double steel) & 7 frictions. (I have checked parts fiche on CMNSL website and according to it, K6 & K7 clutch baskets have identical part numbers. I hope that is correct? I suppose I'll soon find out)

[bigring]

Thanks Disco.  Yeah, been reading up on them here and other forums....like I said, seems there are different ideas of what parts you need.  Two different diagrams/parts - first is from the Yamiya site, the second (linked - can't capture the image - is from the CMSNL site)



http://www.cmsnl.com/honda-cb750k6-four-canada_model14381/partslist/E09.html#results


I am thinking the PO did not use the outer friction disc (disc B) and just used a regular one.  I'm thinking that I'll get one, try it and see how it goes . . . like you said, it's easily accessible if I need to change it. 

Any ideas on the numbering (8 & 7) on the disc flanges?? Aftermarket markings?

I'll post up a photo of the basket later today/night.  Thanks for the advice!

[lucky]

Don't worry about the (7& just have metal- fibre,metal- fiber etc.,.

[bigring]

Thanks Lucky!

[disco]

Hi Bigring,

Just to let you know.....I just jumped straight to my 2nd option tonight which was installing the newly purchased longer K7 clutch hub with 6 steels (5 regular & 1 double steel) & 7 frictions. I'm back to snickety-snick gear changes! Yee Ha!! It has also quietened the clutch down considerably which is an added bonus! I'll take it for a longer ride over weekend & see how it goes but so far I'm very happy. No more clunking into 1st gear....it's back to like a Honda....smooth!

[disco]

Hi Bigring,

I've not seen the markings on the frictions before. Possibly done by the P/O? If your basket is an original K6 type, running a regular square cut friction will make it really noisy. The square cut type friction wont fit correctly in the outer position. It will slop around. Examine your basket & you'll see what I mean.

btw this attachment may be useful for you. I can recommend the double steel Goldwing type plate as a worthwhile upgrade.

[bigring]

Awesome Disco! Glad to hear yours is running smoothly - let me know what you find after your longer ride.  Just ordered me an outer friction disc - my basket is scarred up some - probably the sloppy play. Double steel plate eh?!  Can't hurt to try at all - where did you get that attachment?

[strynboen]

i have just dropped that douppel plate in my 550.. and put inn  a ekstra set plates,,, ...it gives a bit slack. fills not as the dubbel plate.but can be adjusted to vork fine..and gives more grip( plate areial)...the duppel plate vas put inn  for noise /vibrasion reduktion..but it work fine vitaut it