Have you considered using the Kwik-fill fuel valve, if I am not mistaking I believe it offers a valve that will divert fuel to the tank and not the carb.
Edit in:
OOOPS Sorry I guess I missed the statement,
I don't have room for a qwick fill kit but the fuel line on my OS46FX in my Magic is very hard to get to.
I had just asked the moderator to remove this post in which he did and here I go putting the post back. *fatigue sets in*
Randy