Clutch question

[penman]

My 350K2 has been off the road since November, while the tank, etc were away being painted. Now reassembled, I got ready for a celebratory ride, only to find that the clutch wouldn't release. Last year I fitted new friction plates (NLM) and checked and cleaned the metal plates. This was done following the instructions in Paul C's excellent video, so the metal plates were given the orbital sander treatment. Since then, the bike has done about 1000 miles. The clutch has always dragged a bit and it is impossible to engage neutral when stationary. In addition, false neutrals have always been a bit of an annoyance.

I now stripped the clutch and found as expected that most of the plates were sticking together and had to be prised apart with a screwdriver. There was no contamination, in fact the plates all looked clean and dry - but sticky. I cleaned everything with brake cleaner and scuffed the surface of the friction plates with 180 grit emery. I also repeated the sander treatment on the steel plates, though they appeared clean anyway, with no burrs, etc.

That cured it and the clutch is significantly better. Much less tendency to drag, less evidence of false neutrals (the one between 5th and 6th is still an annoying problem) and you can even select neutral when stationary - well, sometimes!

Has anyone else seen this problem? I wonder if it will recur?

Joe.

[72degrees]

When I started the rebuilt 350 in the 'project' for the first time since standing for months the clutch was 'stuck'. I just banged it in to gear a few times until it freed up That has new friction plates, plain plates, and springs. It also has the 'spring assistance washers' borrowed from the 375 so that probably is inclined to stick the plates up a bit if not used regularly. Only done about 100 miles if that. It doesn't drag at all but is inclined to be a bit switch like and grabby. The conical plate is in the Evguru advised position. I guess I will have to check the end float again and review the condition of the centre and basket. I dressed them with a fine file to remove notches and I've seen much worse without similar symptoms. Didn't notice any stickiness last time it was apart. When I find a tuit I'll try your scuffing trick.

[EVguru]

If the clutch is dragging, it's possible it's overheated enough to deposit resin from the friction plates onto the the steel plates, especially with new plates that have not been 'cured'.

It takes very little warp in the steel plates to eat up clutch travel and lead to a tendency to drag.

Most people are just too damn mean to spend the extra £15 for a complete clutch plate set.

[penman]

Haha - yes, I'll take that one on the chin! Yes, I was too mean to spend the £15. Trouble is, as we all know, these old bike restorations burn up money like it was going out of fashion and if you can claw back a few £ here and there, you tend to do it. In fact the original plates had done less than 2000 miles (mph speedo) and I only changed the friction plates because they had started to de-laminate for some reason. I checked all the plates on a sheet of glass and they seem to be perfectly flat (apart from the dished one).

By the way, 72degrees, when I said "scuffed" I was searching for a word - my intention was just to remove the shiny surface from the discs - having stuck once, I didn't entirely trust it. It has certainly improved the gearchange, so worth doing I guess. In the bike's defence, I've never encountered a clutch which was so easy to work on before - I doubt if the whole procedure took 20 minutes. It's still a pretty sharp clutch though - "grabby" is probably over stating it - let's just say "digital" - it's on or off! The one on my 500 is exactly the same, though noticeably lighter for some reason.

Joe.