Yes. I believe the gas cap off the tuber models work and they lock.
http://www.ebay.com/itm/Buell-gas-fu...sories&vxp=mtr
However, don't go blowing 80 dollars on a cap. I have one that I would let go for much less. It is used of course, but still in pretty good condition. PM me if interested. I can also provide pictures.