dca

Turned my bike off, closed the gas line, and then a small gas leak (about a cup) dripped on the garage floor. There was a hissing sound as it did that. 12 hours later, no further gas leak. The tank is 1/2 full, and I had riden it about 25 miles before the leak. Any suggestions as to the cause? Thanks Dave V Star 1100 Classic 2000