Clutch problem.

cleancut · Post by **cleancut** » Fri May 05, 2006 10:51 pm

Can anyone please suggest what to do when a clutch
only takes up right at the end of the lever travel.
This problem is driving me up the wall.
It's a five plate three spring type. The gearbox is
standard Norton. Pushrod length 9.7/8".
The clutch itself is in good order with all the plates
flat and free off burrs etc.
Ive followed the book in adjusting, ie Half turn back
for clearance on clutch centre screw. 1/8" play at lever.
Ive even gone to the length of replaceing the operating
lever (cam) with one from a commando ( slightly different profile )
Still no joy.
There's no problem with slipping once the drive is taken up it's
just the fact that I would prefer a gradual feed especially when
driving in heavy traffic
Any help would be really appreciated. Thanks, Andy.

itma · Post by **itma** » Fri May 05, 2006 11:30 pm

try less than a half turn, and I hope thats not 1/8 at the bar end?

Biscuit · Post by **Biscuit** » Fri May 05, 2006 11:33 pm

If this is an AMC box, are you completely slackening off the cable adjustment before you adjust the centre screw, this is essential. The cable is not used to adjust the clutch withdrawal mechanism.

cleancut · Post by **cleancut** » Sat May 06, 2006 8:28 pm

quote:
If this is an AMC box, are you completely slackening off the cable adjustment before you adjust the centre screw, this is essential. The cable is not used to adjust the clutch withdrawal mechanism.
Thank's for the advice. Yes the cable is completely slack with the cam lever sat on the roller. I am aware that the cable play's no part in the matter.
It feels like the problem could be overcome by adding an extra plate in the clutch but that is'nt possible.
My next move could possibly be re-profileing the original lever
to try and obtain a more gradual feed in.
Thanks again, Andy.

cleancut · Post by **cleancut** » Sat May 06, 2006 8:40 pm

quote:
try less than a half turn, and I hope thats not 1/8 at the bar end?
Thank's for your advice. I've tried a closer contact with the centre screw and yes perhaps 1/8" is excessive at the lever but that was only quoteing the manuals advice. Ive tried the most minimal ammount of slack, still no joy.
Thanks again,Andy.

itma · Post by **itma** » Sat May 06, 2006 9:27 pm

Try altering pushrod lengths, I`ve no data for correct length, someone will have.
maybe take a plate out?
what is the bike?
another thought, perhaps the friction material is too thick on the plates?
long time since I had any dealings with these clutches but replacement plates had far too much material on them and I regullarly skimmed off 1/ 16 or more each side, just to get them all into the drum
1/8 at the handlebar is far too muchEdited by - itma on 06 May 2006 8:28:44 PM

Biscuit · Post by **Biscuit** » Sat May 06, 2006 9:38 pm

Ken it's a 1964 Model31. If the roller sits properly in the cam lever, how will shortening the push et al help?.

itma · Post by **itma** » Sat May 06, 2006 10:13 pm

just clutching at straws Alan; memory wobbly on these boxes now. long time no see.
and looking at the post again I see I`d got completely the wrong end of the stick any way; sorry chaps long day, off to bed now

Edited by - itma on 06 May 2006 9:19:49 PM

Derek Cooper · Post by **Derek Cooper** » Sun May 07, 2006 12:05 am

I totally sympathise with you Andy, I have exactly the same problem with a '65 heavyweight 500 single, and have been unable to resolve it. Does anyone Know if we should be using handlebar levers with 7/8" or 1 1/8" pivot to cable nipple centres? This may be the next thing we should try.
Derek Cooper

Biscuit · Post by **Biscuit** » Sun May 07, 2006 12:13 am

Surely different pivot radii would just increase the clutch disengagement, the problem of engagement at the last moment would still remain.