Thanks guys,
Grumpy, I don't think I have a cotter pin, I have two square headed bolts attaching the clutch to the crankshaft. I have undone these and can move the clutch about 1cm away from the engine, doesn't seem to be enough though.
Tezza, sucks if I have to remove the engine, sounds like a lot of work. I have undone the small housing on the other end of the shaft, but it just spins, like you said, must be a bearing attached to the shaft.
