Pain in the rear what's it, I bought silicone sealant and cleaned it all with isopropyl bought from the chemist. It seemed to workout but that bike is gone now, so long term I don't know.
ok sorted have ordered the Wunderlich dry safe oil cap replacement system , pricey but it will cost me that in oil in the end and surely if oil can get out the water could get in. Bought online from Rainbow