Cota 200 clutch drag

[peterh7]

Hi, I'm having a problem with clutch drag on my 1981 Cota 200 and would appreciate some advice.  I recently had the motor repaired (a kickstart bush collapsed and fell into the gearbox) and clutch was out of the motor for a few months while the motor was split.  Since putting the motor back in the bike and getting it going again the clutch has been dragging (by drag I mean if I put it in gear with the clutch in, it will creep forward). While the clutch was out I replaced the clutch springs with new ones but they made the clutch very hard to pull in so I've put the originals back. I've had them checked for pressure and reassembled it pairing the springs to try to ensure there is even pressure.   After doing this and putting the clutch back on it didn't work at all, but when I rode it around for a while it began to work.  Another rider I know who has owned Montesas suggested doing this because he said it can take a while to get oil back onto the plates if they get dry.   On Sunday I rode in a club trial and the clutch worked fine for a couple of laps then started grabbing again. The small brass push piece looks ok and I think I've been assembling correctly with the chamfer towards the clutch release lever. The 3 finger plate also looks ok.  I'm wondering if new clutch plates might help?  Or if I should take the clutch plates out and make sure they all have oil on them?   Another suggestion I've had is to use ATF oil but I'm not sure if that's wise.

[feetupfun]

You say it is dragging and later say it is grabbing. Is it doing both or just dragging?

Dragging can be caused by lots of things but on an all-steel clutch, grabbing usually means lack of oil

Edited August 7, 2019 by feetupfun

[peterh7]

Yes it is dragging not grabbing.  I was using the wrong terminology, thanks for correcting me on that.

[feetupfun]

They can drag for a few possible reasons:

The plates may not be moving parallel when pushed, although it sounds like you have been pretty careful to avoid this.

There can be grooves in the basket fingers that cause the plates to push together if they see any contact.

One or more plates may not be perfectly flat, meaning that the axial travel of the pressure plate may not be enough to free the plates from contact due to the increased effective thickness of the bent plate/s. All-steel plates spanish clutches typically have a long engagement because the plates are not quite flat. The original plates are stamped while modern replacement plates are laser cut, so they are flatter. As well as starting out not quite flat, steel plates sometimes distort with use, because they are so thin. the flatness of the plates can be checked on a flat surface like a quality piece of glass or a surface plate if you have one.

It's possible that when reassembled, the plates were not put back in the same sequence and position in the basket and the effect of any grooves in the fingers may be now more severe.

There may be insufficient axial clearance between the clutch hub and the basket and this may make the problem temperature-sensitive. If the clutch action improved again once the motor cooled down then I would be looking there.

Next time you assemble the clutch put some oil on the plates and you won't have to worry about them not having oil. From what you've said i don't think that lack of oil or too heavy an oil is the problem. I use car manual gearbox oil in my Cota 348 clutch casing and it doesn't drag.

[peterh7]

Thanks very much, that's very helpful.

[nigel dabster]

I think it has the 12 spring clutch you could probably remove 3