Model 20 Clutch Mechanism Jaming

mescal · Post by **mescal** » Thu Aug 12, 2004 7:11 pm

I'll start by making my excuse that I am a relative novice mechanic and do not know the correct terminology for many parts so please excuse me if I do not make sence.[:o)]

I have a problem where I pull on the clutch lever and the mechanism inside the gearbox outer cover that the cable is attached to (sorry I do not know the correct term) gets stuck[:(]. It's as if it is being pulled too far. It is very easy for me to "unstick it" with a screwdriver through the filler hole.

I can not see a way of preventing this from happeing other than resticting how far the cable pulls (ie loosenig the cable), which in turn means that the clutch is not working properly (ie I can not get into gear).

Any ideas, hints, tips, or knowledge greatfully recieved.[:)][:D]

Biscuit · Post by **Biscuit** » Thu Aug 12, 2004 8:31 pm

What year, or which gearbox?.

mescal · Post by **mescal** » Fri Aug 13, 2004 11:17 am

1955

Biscuit · Post by **Biscuit** » Fri Aug 13, 2004 1:18 pm

Hi Alan, glad to see your name is spelt the correct way!. You have, or should have the B52 gearbox. The clutch withdrawal mechanism works by three balls riding out of dimples when the clutch lever is operated. There are two adjustments, the cable adjuster at the gear box end, and one in the clutch spring pressure plate. To adjust, slacken cable adjuster at gearbox end as far as possible, ensuring that the cam plate, ( the bit you push back) is pushed back. Nip round to the near side of the bike, the clutch dome cover may have a small inspection plate in the centre, the whole dome may be removeable, or worse case scenario the whole outer chaincase may need to be removed. On your model, the dome should be removeable, but who knows what may have happened over the years?. Having done whatever to gain access to the pressure plate, slacken off the centre locknut and screw the centre thrust cup in until it lightly contacts the push rod, undo half a turn and lock with the nut, ensuring the thrust cup does not turn. Nipping back to the offside adjust the cable to give 1/8" to 3/16" play at the lever. Unless the ball ramps are badly worn, this should do the trick.

mescal · Post by **mescal** » Mon Aug 16, 2004 2:00 pm

Thanks Alan. I can confirm I have a removable dome. I must admit I have never looked inside it! Proably should have done since I got the bike back on the road a year ago after 15 years in someone elses garage - still, live and learn etc.

I will post again when I have had a look/attempt at ajustment (this may be a while - no garage to work in and quite a lot on at the moment).

Robbo · Post by **Robbo** » Mon Aug 16, 2004 5:05 pm

quote:Originally posted by Alan Smith

I'll start by making my excuse that I am a relative novice mechanic and do not know the correct terminology for many parts so please excuse me if I do not make sence.[:o)]

I have a problem where I pull on the clutch lever and the mechanism inside the gearbox outer cover that the cable is attached to (sorry I do not know the correct term) gets stuck[:(]. It's as if it is being pulled too far. It is very easy for me to "unstick it" with a screwdriver through the filler hole.

I can not see a way of preventing this from happeing other than resticting how far the cable pulls (ie loosenig the cable), which in turn means that the clutch is not working properly (ie I can not get into gear).

Any ideas, hints, tips, or knowledge greatfully recieved.[:)][:D]

Biscuit · Post by **Biscuit** » Mon Aug 16, 2004 11:48 pm

Nice quote David, but what point are you making?

mescal · Post by **mescal** » Thu Aug 26, 2004 5:47 pm

Thanks Alan for the advice. It worked a treat, even though the centre thrust cup and locking nut on the pressure plate are now right at the end of their asdjustment.

But, I now have even more problems:

Having adjusted the clutch I found I could not move through all the gears (probably couldn't before I adjusted the clutch). I suspect the worst and that I have done some damage when trying to change gear when the clutch first failed.

I took off the outer case could see nothing wrong but was not sure which position the gear change mechanism (the bit with the little studs stciking out) should be in, but trying various positions did not seem to help. At one point I had thought I got it to move through 4 positions but when I put the case back on it did not work.

So getting wreckless I thought I would take off the inner case to have a look. I removed the little split pins so the gear change mechanism could be removed and removed the clutch pushrod, However I am now in a position where the inner cover has come only part way off and it does not seem to want to go back on either!!! I suspect I have done something very stupid but can not see what is preventing the movement.

Any advice or knowledge or even general ribbing pointing out my mistakes will be appreciated.

Biscuit · Post by **Biscuit** » Fri Aug 27, 2004 12:19 am

Haven't had one to bits for a long time, but you have to remove the mainshaft nut securing the K/S ratchet to release the inner or K/S cover. It may not want to go back due to gears having moved and not meshing. I think we need help from someone who has done this recently. I think you may need to start from scratch now, removing gears, shafts and selectors and assembling them as a unit, then popping them in the box.

mescal · Post by **mescal** » Fri Aug 27, 2004 2:51 pm

I had a feeling the gears meshing might be part of my problem as you suggest, Alan.

I have removed the kick start rachet (behind it I can see a circle of ball bearings that seem to be attached to the inner cover).

Further advice from anyone will be greatfully received as usual.