Major gas leak

[Wheaton Jr.]

So about a week ago, I had tried to start my bike, but the battery was no good. So I bought a battery online and waited for it to arrive. In the meantime, I had forgotten to turn the petcock back to on. It was on prime. It was on there for probably 3 to 5 days. So, there was some gas on the driveway, but I cleaned it and it was ok. Then 4 days after that, the battery came and I tried to start my bike. It was trying to start and it was cranking, and I could tell it was going to start soon, but as the RPM's barely went higher than 0, I saw that there was gas spurting out from under me. I quickly shut it off and noticed it seemed to be leaking from one of the carburetors on the left side. I cleaned up the mess, and put the bike in the garage. When I came home 4 hours later, there was a 6 by 6 feet puddle of gas in my garage. I was wondering what people thought was the problem on here. Was it only because I had left the petcock in the prime position, or are my carb seals going bad or something, im not sure. Thanks for all your help. David