CORK CLUTCH HELP - BIG PORT

[Luddite]

My big port clutch slips!  It's making the bike almost unrideable.  The corks are oil-free and in perfect condition, the plates are smooth and parallel, the (single, central) spring is fitted correctly, there's the correct free play before the rod is actuated.  I've checked everything.  Twice.  What have I missed?  Or is there a way of making cork clutches grippier?

[geoffus]

 :)it's a long time ago that I had a big port I don't remember any clutch problems  there is a key in the boss of one plate that if it fouls the end of the slot in the shaft it would pervade from engagement of the clutch
I can't remember what I the pump set at that I think it was the one drip about every 30 35 seconds one thing is certain the sight class should not be full you could take pump off and check that the oil hole is clear one other thing you could check is that the pump in the tank is not let in oil through into the engine there is a spring and a ball bearing in the hand pump check on that what I do remember is that it took according to the book 2  pints for 500 miles best of luck  geoffus

[Luddite]

Thanks for that - I hadn't checked the keyway  I'll get onto that this evening.  Ditto the handpump - it's likely to be siphoning from there rather than coming in from the other side.

I could strip that clutch in my sleep now!