Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
PS any idea how far back the oil hole is? then I can judge it as I can recall the thickness of the seal.
The O-Ring is a thicker chain than standard so check where the rivet pins go as it goes around the front sprocket, there are some reports of them gouging a track in the crankcase, hitting the chain guard that you're after and on the 500 breaking the clutch push rod. See if you can spot any shiny areas where it might be touching.
Grease is ok, looks like plastic to me.Just checked the 500 cases, it has the same oil hole, same diameter. However after refitting an old seal it appears it's not possible to drive the seal in enough to block the hole, the hole is lipped as you can see and the lip stops the seal before it goes to far in. It's possible to sink the seal a little if you drive it right down to the lip, so that would explain yours Jezza, however it won't block the hole.
Just a quick update that Julie’s oil pump rebuild kit solved all my leak problems. Buy with confidence 😊