murben

So, i have a 1985 maxim 750 that has been running great up until now. All of a sudden, when i start the bike, fuel starts pouring out from under it. At first, i assumed a fuel line had come loose or broke, but after tracing it out, it looked like it was coming out of the rubber boot that covers where the drive shaft mates to the engine. After pulling back the boot, sure enough, it was a mix of gas and oil (mostly gas now) just pouring out from the spot where the shaft leaves the engine case. Any idea what exactly would cause this to happen, and happen this bad? I'm assuming piston rings or something, but what could cause it to be this bad all of a sudden? The gas just pours out of there in a steady stream. thanks for any help!!