Topic: Starting to lose it!!Clutch Help!

[CB750 SS]

It starting to cool down here in the south and therefore it's time to go back into the garage.

I have a CB750 SS 1976 that I rebuild the engine on last year.  My first rebuild and it WORKS.  I'm pretty proud of this accomplishment.  However, I can't figure on what happening with the clutch.

http://www.salocal.com/sohc/tech/clutch/cth1.htm

Looking at this link I can'tfigure out what I'm doing wrong.  When I put it back together I can't get the clutch level to have any effect.  With the engine on it drops into gear and stalls the motor.  All I can think (having had it apart 12-15 times) is it needs to be swimming in oil and I'm testing too soon? Additionally, the tech manual and the salocal link have a number of different parts.  For example, I (and salcal link) don't have a Clutch plate stopper ring.  I also added a Spline Washer that I don't think was in there before. My other theory is the spring are 30 years old and not strong enough to push the pressure plate back and therefore reduce the friction on the discs. 

My second confliction! What the heck is that thing below the alternator rotor housing.  it's a weird breather the size of a quarter, a wire screws into the middle of it, on the bottom of the motor.  It's leaking oil and I can't find any information on it.  BTW - during my rebuild I didn't touch it.

Please help!  I'm very near picking up the bike and tossing it around the garage.  At 500 lbs I might pull something 

[mystic_1]

Well, first off the clutch springs actually press the clutch CLOSED, so weak springs probably aren't your problem.  Oil also shouldn't affect your ability to open the clutch, but you're right that there should be oil in the clutch, 750's have a "wet clutch" system.



When you squeeze the clutch lever, the cable pulls on the actuating arm (#4) in the clutch outer housing, which turns the little plate that bears against the part with the three ball bearings in it (#6).  These balls ride up in the little ramps on parts #6 and #9, which forces the adjusting screw (#8) to press inwards on the clutch lifter plate, see next diagram:



So, the clutch lifter plate (#8) moves inward against pressure from the springs, causing the clutch pressure plate (#7) to move inwards, away from teh clutch center (#2).  This opens up the friction plates and steel plates and allows the parts to spin freely, in other words the clutch is open.

So, that's how things should work, if they don't than there's something either not adjusted properly or not assembled properly.  IF you're following the adjusting procedure by the book, and feel confident that you're adjusting the clutch adjustment screw properly, than the next most likely problem is improper installation of the clutch lifter plate relative to the clutch center, the splines only mesh properly in one configuration although you can put it together four different ways.

See the following post for details and pictures:

http://forums.sohc4.net/index.php?topic=36525.msg377135#msg377135


hth
mystic_1

[mystic_1]

My second confliction! What the heck is that thing below the alternator rotor housing.  it's a weird breather the size of a quarter, a wire screws into the middle of it, on the bottom of the motor.  It's leaking oil and I can't find any information on it.  BTW - during my rebuild I didn't touch it.

That would be your Neutral switch, #13 below:



It's not a breather, and shouldn't be leaking oil.  If the oil is coming from the perimeter than the o-ring is probably shot, if it's coming from the center than the switch is bad and needs to be replaced.

mystic_1

[CB750 SS]

Well, that couldn't have gone any worse.  On the first rebuild it classically didn't disengage. Locked in direct drive mode.  On the second build same thing.  I'm not have a problem getting the basket inside or closing it up. I'm also not having trouble adjusting.  When I disassembled the clutch the plates and disk were alternating. On the last build, after arranging the disks and plates closer to the diagram.  BTW - I'm starting to think my bike doesn't use a spline washer. Does it need other two items within the disk/plate assemblythe pressure plate and lift broke. WHAT THE !!!!!!!!$%#%#%#!!!!!!!

can some tell me how a CB750 SS plate/disk are supposed to be arrange.  Additionally I order the parts from PartsNmore.  could they be wrong?  This is just nuts.

[CB750 SS]

one things for sure, I'll be a master clutch man at the end of all this. I hate learning!  I'll let you know how things go once the parts arrive.

[renegade balloon]

I had the same problem on my 74 CB750. Take clutch plates and soak them in fresh oil overnight, then re-assemble. The clutch may still still catch a little in neutral but after running it for a little bit it will start functioning like normal.