Z1OwnersClub GB

there is a oil drip coming from behind the front sprocket,
maybe the gasket on the casing behind the sprocket,

has anybody got a diagram of that area to make it easier to see what should be there ?

anybody had this problem before?

There is a very thin o-ring which is often overlooked behind the sprocket on the sprocket shaft.
Remove the tab washer and undo the sprocket nut (hold down on rear brake).
Behind the sprocket you will be able to remove a ground steel sleeve. You will see it has a small chamfer on the inside which is where an o-seal should be seating. It is very hard to see as it is very thin.
RegardZ.

check that its not dripping from the gear change shaft where it passes through the transmission cover, that oil seal is prone to leak

Chris