Thanks, that's encouraging.
It dosn't seem to drip when fuel is left on and not tickled, which did make me wonder.
If it is due to over tickling, it seems to take a long time for the surplus to stop running.
As I have a small remote fuel container I can suspend beside the bike, I will take the tank off tomorrow and connect to this remote supply. This will make it easier, both to see what's happening to the fuel level, and to try starting without so much risk, if fire does occur again.