C15 continuous oil leak

[MOONSDRIFT]

Can I ask all the  C15 experts, what is the likely cause of oil continually leaking from the gear change shaft, this appears to be a strait through leak from the oil tank, it leaves a puddle of clean oil without the bike moving or running, it just started  to leak without any pre wetness or dripping. I have removed the cover only to find a machined weep hole from the gearbox inner cover, presumably to oil the kickstart.

As you may of deduced, it has been a very long time since I worked on a bike
Any help would be appreciated.
Thanks
Mark

[MOONSDRIFT]

Does nobody have any suggestions, this must of happened before to somebody

[johnan]

If it is engine oil from the remote tank then the bottom of the engine must be filling up with oil, feeding through to the outer casing and then filling it high enough to find its way out via the gear change shaft.   
When you took the outer cover off there would have been a deluge of oil coming out, if that is the case.
The anti wet sumping valve In the crankcase must not be working for that to happen.
Has the oil level in the tank dropped much, unexpectedly?

If it is not engine oil then it has to be gearbox oil, and again there would have to be a lot in the outer case to fill up to the level of the gear change shaft, so a lot would have come out when you split the cases. Maybe the gearbox was over filled, if the leaking oil is gearbox oil.

[MOONSDRIFT]

Thanks Johnan, it emptied the remote tank in a few weeks, the bike has stood for a few years, but this happened al at once. Looks like it may be the anti wet dumping valve may be the cause then - a simple fix

Thanks
Mark