Oil leak output shaft help

Hi,
I've got an oil leak on my '99 curvy on the nearside of the engine. Three most likely sources are the output shaft, clutch push rod and gear selector shaft,

It's definitely not the gear selector shaft as the oils tracking from above. It doesn't look like the clutch push rod oil seal. So that leaves the output shaft, which is my bet.

I've looked at the pdf manual and it's not very clear, it talks about putting the grooved side of the engine sprocket spacer facing the engine and applying grease to the oil seal lip and O ring??

Do I need to replace both of these??

where's the O ring???

The oil seal sits in the crankcase, then the oil seal retaining plate i can see that.

Help please.

O-ring is inside spacer.

All sorted,

Wasn't any of the oil seals, there's a crankcase breather pipe just above the sprocket, this was off, so venting oil mist. Must have pulled it off when I was balancing the carbs, more care needed!

Had to taken the engine sprocket off be i notice, so it's still cost me the price the sprocket retaing nut and locktab!

Still quickly fixed I like that.

[Biker Biggles]

Dont forget to do it up tight,with locktite and then some elbow grease.