Surflex clutch plates

Does anyone know the thickness of a new Surflex friction plate? Mine vary from 3.48 to 3.52mm (4 total). The plain plates are 1.92 to 2.04 (5 total - the extra one is for a lighter clutch pull)

I'm having a bit of trouble selecting neutral with the engine running. The clutch is set up 100% correctly so I suspect the plates may be over their wear limits.

mike916sp said:

I'm having a bit of trouble selecting neutral with the engine running. The clutch is set up 100% correctly so I suspect the plates may be over their wear limits.

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Presumably, you are experiencing some clutch drag?

Although I can't see how worn friction linings would cause, or contribute to that problem, provided they hadn't worn unevenly, or become warped?

Mike, as LAB says, some wear should not cause serious problems. Assuming you haven't got massive play at the pushrod or lever (following the manual does produce a lot of free play and will make clean clutch releasing difficult in my experience). I adjust until the operating screw is just touching the pushrod, taking up all play in the system. As it warms up play at the lever increases, well mine does and I don't have any pushrod wear issues.
What does have an effect is an uneven/warped diaphraghm spring. You have to pull it off the clutch and set it up on a surface without the release boss. If the fingers are clearly different in height clean release is difficult. After doing all the recommended clutch mods mine never worked well until I changed the spring. Also assume the primary chain/belt is not too tight?

Overtight primary chain / belt can give clutch drag symptoms, as Keith mentioned. After easing my chain to give about 10mm freedom in mid point, gearshift and neutral selection were really good. Belt drives need much more slack.
It is also worth checking the end float on the kickstart shaft. 10 thou or so is ok but above that can cause drag and poor shifting. The workshop manual does not mention adjusting this end float but there are Norton shims available for some other part of the bike which fit exactly. IIRC they come in several thicknesses and I shimmed mine out to eliminate excessive end float, improving selection in the process. I think the part numbers I used are 060775 (.005") and 060777 (.020")

scim77 said:

there are Norton shims available for some other part of the bike which fit exactly. IIRC they come in several thicknesses and I shimmed mine out to eliminate excessive end float, improving selection in the process. I think the part numbers I used are 060775 (.005") and 060777 (.020")

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Those part numbers are rear Isolastic shims.

Some interesting thoughts there.

The bike has a standard primary chain which has not been adjusted recently and I do not experience any noticiable creep problems with the bike. It normally goes into neutral with only the lightest of touches of the gear lever which is why I suspected the clutch rather than anything to do with the gearbox. I rebuilt the gearbox 18 months ago and it is realyy smooth but must admit I did't check for end float or shim the kickstart shaft.

I've stripped the clutch and got four new plates and fitted them this afternoon and also cleaned out the basket. It was pretty well mucked up with bits of clutch material between all the grooves in the basket which may not have helped the plates to release cleanly.

I'm just waiting to test it at the moment but the rain is coming down at the moment so I will wait until tomorrow to see if there is any improvement.