Topic: CB750K4 Clutch Reassembly Mistake?

[Wingnut74]

Clutch is killing me. First I break off a bolt trying to remove from clutch plate bolt. So buy new one on ebay. I looked at the parts fiche and its the same parts number for 74 and 76 so I buy it.  So like a dope I was not careful enough, even though I thought I was, and broke the clutch lifter on one of the arms. Bought NOS replacement off ebay OUCH!!the  replacement lifter on Ebay was for a 76 CB750 K confirmed part number  . Was super careful this time in tightening bolts and thought I had success but after tightening up to 80 inch lbs, when it is in gear I can turn the center of the clutch and while there is significant resistance, the basket does not move with it perfectly and slips mostly. I would expect that the clutch lifter plate/center and basket should be locked tight. I have some slim hope that someone tells me this is OK at there is solid friction once the inner is spinning but not too sure about that. Saw another post where someone got wrong 750F part but don't think that is the case here. Help! thanks

[Jerry Rxman Griffin aka MuthaF'er]

Post some pictures of your assembled basket. Really easy AFTER you figure it out and break a few things at first. It's gonna piss you off even more once you figure it out 

Gotta be careful mixing and matching clutch parts but it'll work.

[Steve_K]

That darn lifter plate was easy for me to break.  I moaned and groaned and then read some posts on how to do it with out breaking.   I learned something from that.  This forum helped me to do it the correct way.
Steve

[mystic_1]

Any chance this is your issue?

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.



So again, don't know if this could cause your symptom or not but it's worth check, just to be sure.

cheers
mystic_1

[Wingnut74]

I took it apart, reassembled studying the fit of everything and I think that may have been exactly the problem! thanks! it works now.   slowly getting there and enjoying almost every step of this rebuild. engine is almost back together

[mystic_1]

Sweet! 

mystic_1