Topic: Clutch 1970 CB750

[DaveInTexas]

Ok none of the recommended tricks to unbind my glued-together clutch plates worked (locking rear wheel with clutch pulled etc).

So I was planning to pull it.  What I want to ask is, when I pull that cover, should I expect a lot of oil to come pouring out of there?  Just trying to keep the garage clean.
Thanks

[jsaab2748]

Put the bike on the sidestand, a small "flattish" catch pan underneath and remove the cover. As long as the oil pump isn't "wet sumping" (the check valve leaking allowing oil to enter the crankcase w/o the engine running) it should leak very little into the catch pan. Your results may vary, so have a big enough pan just in case. OR just do an oil change, and do your clutch service before refiling.

[HondaMan]

Dave:
These clutches stick when left sitting for long periods of time, but don't pull it apart just yet.

Centerstand the bike and warm it up completely, like 15 minutes running time. During that time, drop it into gear and try to shift through a few gears: this will seem rough, and don't try it a 3000+ RPM. The spinning countershaft action will feed oil to the center of the hub and the plates. When it's well warmed up, then try to declutch and pop into gear with the rear brake on, hard. It might take a time or two. If you get nervous about this, then shut off the engine while hot and put it in gear, have someone else pull in the clutch, and try snapping the rear wheel against the stuck clutch.

I've oftens seen this on bikes with slightly warped steel plates, but warming them up usually will flex them enough to let some oil in and begin loosening it up.

[DaveInTexas]

Well I opened it up, took all the plates out and separated them. 
Cleaned with solvent and then oiled.  Replaced them in the same order they came out.
Put the cover back on and now I am having a terrible time trying to get the adjustment right.

To the point that I am wondering if I did reassemble them correctly.

Before all this, the clutch did not release, although the handle felt right.

When I reassemble it, and get the adjustment close per the shop manual, it feels like I am going to break the cable when I get the Clutch Adjusting Screw even snug.... I haven't even turned the screw the quoted 1/4 to 1/2 turn yet.

Grrrrrrr!

[nteek754]

Hey there  I think you will find  all of the clutch plates didnt  seat all the way in  them little ears gotta be lined right up perfect  I when putting back together  before I put the pressure plate on I put one of the bolts in so I can  twist and work the plates all together  in fact one time years ago  was installing clutch and started tighting  presure plate bolts (you know eack a little at a time) yup 30 years ago in my rookie days I broke an ear off the  plate grrr oh well   when I was tighting the four bolts all of a sudden  SNAP the clutches went in together so I had  an ear or two not quite lined up  hope this helps  seven fifty four ever

[DaveInTexas]

How tight do you put the four 'clutch lifter mounting bolts'?  The manual says, "tighten them" but when I do I am cranking down on the springs!  And if I am compressing the springs, there is nothing for the clutch actuator mechanism to do.  I think the problem is there, but Im not sure quite what the problem is.

[Jonesy]

The bolts tighten down the springs, but they eventually bottom out on the four threaded bosses.

Check out this link for more clutch assembly info:
http://www.salocal.com/sohc/tech/clutch/cth1.htm

[DaveInTexas]

OK I have my clutch figured out!

BUT I have a broked lifter plate.
Any tips on where to get one?  I will try a dealer but I was thinking 'fast' and don't mind used parts if anyone has any leads.
Thanks.

The lifter plate is a diamond shaped part with a bearing pressed into the center. Four bolt holes.
The actuator pushes on this part to release the clutch.

[HondaMan]

Dave:
Search for Boulder Bike Works (Longmont, Colorado). Ask for Keith. Tell him you need the clutch lifter hub from the CB750K4 I tore down with them last Saturday. Mention I sent you, and they'll know which bike it was: it's a real young K4.

I'd give you their phone #, but I left their card at work.

Next time, assemble all the plates until they are flush with the fingers (some call it the "basket"). Also, make sure the cupped side of the washer goes toward the engine. When it is all correct, the bolts tighten down all the way to the bosses without much effort.

[DaveInTexas]

Thanks
I discovered one small trick about it tonight, if you don't jiggle the Clutch Inner (official Honda term) as you pull it away from the bike, you may catch one of the tangs of the plates on an edge in there.  Then when you try to tighten it down, it is not going to seat properly. 
Jiggle and twist left to right, then pull until properly seated. 
Ah well, I can use the wait-for-parts time to continue going over stuff.  Replaced some corroded handle bolts tonight, found one of the plugs was finger tight!, had a look at the fuel lines as I am thinking of those filters everyone mentions, adjusted the bezel on the rear lamp, Hey where does everyone carry their insurance card, I was thinking a protector mounted under the seat?  Rubbed and polished stuff.
My secretary got a kick out of the parts guy, CrotchRocketDotCom calling and announcing himself that way, I tell you she got a lot of mileage out of that one today.