I have the same problem.
I was out bidded by $0.50 by an automatic bidding Ebay system last week. Crappy system. Its probably going to be re - auctioned at $65...no way.
I'm presently working on an alternative solution which is to install a vacuum petcock valve on my tank.
The one I found (from a Yamaha I think) fits on the tank's tread and I'm planning on using the (now plugged) remaining intake manifold nipple from the (now removed) oil pump to create the actual vacuum....should work.
Cost me $15 at my local moped scrap yard...You have to bring your gas tank inside for the guy to find the part. lol