The mechanical water pump seal. I have had it let go about two years ago, about 110klm. Had all sorts of advice such as it will be right when it warms up, will stop leaking etc. End of the day, its not meant to leak from the inspection hole so I got it repaired. A bit outside my skill level. I stripped the bike of all Tupperware, gave the engine a real good clean up and that made it a lot easier for my mechanic to repair and a bit cheaper for me as well. The front has to come off so that gave my mechanic a chance to have a good look inside around the transmission etc for any other problems (which there were not), in fact he commented how clean the gears and cogs etc were for its age.
