Clutch spring retaining nuts

[j2maria]

How tight do you screw the nuts that hold the clutch plate springs? I tightened them in all the way and that seemed to result in a binding clutch. I also assume that if you do not tighten them in all the way, the spring load prevents them from unscrewing without the need for any kind of Loctite?

Thanks

Joe

[George 350]

Hi,
They came from the factory fully screwed in and that's the way mine have always gone back, just lightly nipped. Have always added some 'Neverseez' or copper slip to the thread so that they don't rust in place.
If your clutch is heavy, check the routing of your clutch cable - it shouldn't be too tight around the headstock.
Hope that this helps,
George.

[j2maria]

The clutch lever is smooth and there are no kinks in the cable. When you say "They came from the factory fully screwed in and that's the way mine have always gone back, just lightly nipped" I assume you mean that you screw the nuts in till the face of each nut is flush with the pin that goes through the spring? Would that be "just nipped"? Sorry for being so obtuse....

Joe

[George 350]

Hi Joe,
No, I screw the nuts in until they touch the inner face of the drum, ie: they won't turn any further. At this point I back them off a bit and then bring them back until they touch with as little torque as is realistic to apply. When 'home', the top of the thread is about flush with the head of the spring retaining nut/top of the slot. I seem to recall that if you don't screw them in fully they can touch the clutch cover and act like a milling cutter on the inside. I haven't had this happen to me but I'm sure I remember someone have this occur years ago.
You say you have a binding clutch. Do you mean that it won't release fully? Lots of people would use the term ‘dragging’ where at the least makes getting neutral a pain, while at its worst will stall the engine when you select a gear. If so, here are some more questions:
Have you replaced the thrust washer as part of the rebuild? If so, did you shim up the end float on the drum correctly?
If you haven’t replaced the thrust washer, is there any end float on the drum?
Is the actuating arm adjusted ok? in my experience you need the arm as far out from the engine as the cover will allow.
Clutch plates - correct number? One 'thin' friction plate? One 'dished' steel plate?
Clutch plates flat (apart from the one ‘dished’ steel plate)?

In my experience, the Morini clutch, once the ancient brass thrust washers were replaced with the nylon ones (can there be any brass ones left?) was never a problem area. Didn’t drag, and only slipped when the oil seal went and made it a wet clutch. By the way, from your first post, definately no Loctite. See my first reply about copperslip
Hope that this helps,
George.

[j2maria]

>>You say you have a binding clutch. Do you mean that it won't release fully? Lots of people would use the term ‘dragging’ where at the least makes getting neutral a pain, while at its worst will stall the engine when you select a gear.

It stalls when I "crunch" into a gear. With the rear wheel off the stand, when I engage a gear the wheel turns. When I hold the rear brake down it stops turning.

>>Have you replaced the thrust washer as part of the rebuild? If so, did you shim up the end float on the drum correctly?

While I did not replace the nylon thrust washer but it did not show much wear (this 1980K1 has only around 10k miles on it!) and I replaced it the way the manual says to do it. The end float seems to be a little less than 0.5mm which I assume is OK?

>>Is the actuating arm adjusted ok? in my experience you need the arm as far out from the engine as the cover will allow.

I tried several distances from the case starting with the standard 15mm spec. I have now adjusted it to where when the hand clutch lever is fully pulled in, the arm just about clears the case. If I read you correctly, this is too close to the case and the tip of the clutch arm should be as far out as possible when the handle bar clutch lever is not pulled in? There does not seem to be much wear on the part of the arm that pushes the clutch pushrod. Another method I have used on my other bikes is to slip a piece of paper between the arm and the clutch pushrod and tighten the adjuster screw until the paper is caught.

>>Clutch plates - correct number? One 'thin' friction plate? One 'dished' steel plate?>>Clutch plates flat (apart from the one ‘dished’ steel plate)?

I have the right number and order of plates and the plates and springs are well within the specs. HOWEVER, there is a thin fiber plate that was the innermost plate when I removed the clutch. Also, for the life of me I cannot visually see the dished steel plate - all of the steel plates (and fiber) seem perfectly flat! I have not put them on my granite surface plate but will do so to see which one is dished.

>>only slipped when the oil seal went and made it a wet clutch

There was no oil inside - seals are all good.

>>I screw the nuts in until they touch the inner face of the drum, ie: they won't turn any further. At this point I back them off a bit and then bring them back until they touch with as little torque as is realistic to apply. When 'home', the top of the thread is about flush with the head of the spring retaining nut/top of the slot. I seem to recall that if you don't screw them in fully they can touch the clutch cover and act like a milling cutter on the inside.

I think this might be my problem - I have them screwed tight all the way down to the point where I can see at least 2 threads projecting from the spring retainer nut. This possibly prevents the clutch plates from fully releasing? I will try it tonight.

Thanks again for you help

Joe

[EVguru]

I have the right number and order of plates and the plates and springs are well within the specs. HOWEVER, there is a thin fiber plate that was the innermost plate when I removed the clutch.

That would be the previously mentioned half plate.

Also, for the life of me I cannot visually see the dished steel plate - all of the steel plates (and fiber) seem perfectly flat! I have not put them on my granite surface plate but will do so to see which one is dished.

All of the plates in the early clutch were the same thickness (2mm as I recall). The conical plate replaced one of them to improve the clutch action. It's thinner, but the same height (because of the dish). The difference in thickness is quite noticeable. Contrary to the 'Blue Book' the conical plate should be the first steel plate in, not last (revised procedure in the Cagiva published manual). Remove any burrs from the centre drum and I find it helps to flatten and de-burr the steel plates with wet & dry on a surface plate. Check that the pressure plate is lifting squarely. If not your clutch springs may be of uneven strength, or the lifter 'mushroom' may be bent. Spring retaining nuts should be screwed home, ie. all the way, but don't 'tighten' them as they may jam and spin the stud next time you try and service the clutch.

[j2maria]

>>All of the plates in the early clutch were the same thickness (2mm as I recall)

I guess I must have an early clutch as all the steel plates are the same thickness measured at various points on the radius of each plate.

>> Remove any burrs from the centre drum and I find it helps to flatten and de-burr the steel plates with wet & dry on a surface plate. Check that the pressure plate is lifting squarely.

There were no burrs either on the inner bell, outer drum or steel or fiber plates. And the plate lifts off evenly (I measured identical spring compression for a given load on all springs).

I think the issue must be the amount I tighten the spring retainer screws down. But how far down? Nowhere in the manual does it say whether to tighten all the way (hard), all the way till bottomed but just snugged up, just "nipped" or until the nut face aligns with the stud face? Paul and George: Here are your suggestions in the thread:

>>Spring retaining nuts should be screwed home, ie. all the way, but don't 'tighten' them
>>I screw the nuts in until they touch the inner face of the drum, ie: they won't turn any further. At this point I back them off a bit and then bring them back until they touch with as little torque as is realistic to apply. When 'home', the top of the thread is about flush with the head of the spring retaining nut/top of the slot.

So, I guess I would tighten the nut till the top of the thread is about flush with the head of the spring retaining nut/top of the slot. Rather than worry about whether my backing off was enough, the face of the stud seems to be a good fixed reference to align the nut face.

Let me give this a shot tonight.

Thanks to the two of you
Joe

[3potjohn]

I have a 350K also-I have the clutch set up as Paul suggests and do have the one thinner dished plate. I did get a new clutch pack when I got the bike though in fact the old plates look OK.I have shimmed the clutch and de-burred the slots. all seems pretty good-no crunching but not exactly a positive neutral every time. I adjusted the clutch arm as it nearly touched my chain. I think the "dimple " on the clutch arm is worn. Not surprising really.

[j2maria]

Morini clutch plates.JPG (128.92 KiB) Viewed 14379 times

I adjusted the clutch spring nuts by bottoming the springs and then backing the nut off a 1/4 turn. The face of the nut now is about a thread or so below the face of the stud. However, it does not seem to have made any difference. There is crunching noise when I put it into gear and the rear wheel spins with the clutch pulled in. I tried it with the clutch actuating arm 15mm from the face and also with the arm as far away as possible from the case.

The inner clutch bell does not seem to be any end-float but did spin when I rotated it by hand after removing the plates. I pulled the bell off and checked that I had installed the nylon bush correctly (the 4 "ears" sitting in the allen key recesses). However, there is a steel shim washer in between the nylon bush and the clutch bell that does not seem to be in the parts diag. Maybe, someone installed it to shim away the end-float? I am attaching a photo of the bell with the shim and nylon bush and another photo of the plates.

[EVguru]

Ok, lets assume yours is an early bike (you've never mentioned the year).

Very early bikes had no clutch thrust washer and a Bronze one was quickly introduced, later replaced with a plastic one.

The plastic thrust washer is thicker, so a shim has to be added for clearance where it has replaced a Bronze. If there isn't sufficient clearance, then the trust washer itself will create clutch drag.

There should be a thin film of grease on the thrust washer.

[j2maria]

I assume you meant that the plastic washer was thinner than the bronze bush and that is why a spacer was needed? My bike is a November 1979 K with about 10k miles. The blue manual that came with it shows and talks about the "special" nylon washer but does not say anything about a shim or specify any end float. I did coat the washer with a film of grease before reassembly.

Joe

[EVguru]

OK, a 79 bike should definitely have a clutch pack with a conical steel plate.
Can you stack the steel plates up and take an edge on picture.

The clutch centre hub tightens against the sleeve you can see in the middle of the outer drum. Without the spacer, the hub would be locked solid against the outer drum. The thicker plastic washer needs a thicker spacer.

With the hub in place (but no plates fitted) is there any drag between the inner and outer drums?

[j2maria]

Paul

I looked in the box of parts that came with the bike and did find a thinner metal plate (along with used fiber and steel plates) that for some reason the previous owner did not use. I installed the thin fiber disk first, then the thin metal disk, and then the rest of the pack and tightened the screws down till the face of the spring retaining nuts were flush with the thread bosses. Before installing the plates, I manually rotated the the inner bell (having greased the face of the nylon bush) and bell turns smoothly on the nylon washer, while the outer drum remains stationary with no drag.

So now the all gears except first change without a crunch, take up is gradual, and the rear wheel does not spin with the clutch pulled in - yay! However, there is still a crunch getting into first that seems to vary in intensity as I move the clutch arm in or out. Finding neutral also seems to be a bit of a problem. Maybe, it is now a matter of finding that sweet spot where the clutch pushrod is bearing just the right amount on the plates.....

Joe

[j2maria]

I've got it to the point where it goes into gear with a slight clunk. But it seems to bog down when I let the clutch out. Now, I am beginning to wonder if I have my gear linkage upside down .My bike is 1979 K sold in the US and so I assumed it was sold with the left hand side gear (which it has) going 1 down and 2 to 5 up. However, even though I have restored several bikes I made the elementary mistake of not photographing the gear linkage thinking it was obvious how to put it back.

While the right hand side can only go back one way given the various bits and bobs that get in the way, the left hand linkage which directly attaches to the gear lever can (I now think) can go back two ways. I am attaching a photo that shows the short linkage on the left side that attaches on the top to the gear lever and at the bottom to the cross shaft that carries over to the right hand side linkage. The way I have set it up, the pinch bolt that retains the stubby link arm around the gear lever enters the boss from the bottom and the boss itself is to the rear of the gear lever. The other possibility would be for the boss to lie horizontally below the gear lever with the stubby link arm standing vertical behind the gear lever instead of angled below it (see photo).

Which is the right way?

Joe