I have a 1998 Quadrunner I bought as a project.
After rebuilding the carb, I put some gas in it to test it out. It still needs some work, but after sitting all night the air box had a ton of fuel in it, and most of the gas leaked through the carb and ended up in the motor.

Gas is not suppose to move through the petcock w/o vacume correct?

Also, the carb has to vent lines coming off it, where are those suppose to go? Do they need to be plugged?

I'm thinking I need a new petcock, but I also need to know what to do with those vent lines

 

I'm not an expert, but it sounds like you have a stuck float in your carb. The petcock is to shut fuel off to the carb completely. The float in the bowl is supposed to shut the fuel flow off when the bowl is full. JMO

 

I think its flowing in through the vent side of the petcock. For some reason this petcock doesn't have an "off".
The vent line feeds into the front of the carb, best I can tell.

 

Well, like I said I'm no expert. However there are experts here, so hang tight. Someone will prob post something in the morning.

 

Instead of an off position it has a prime position for cold starts. It lets fuel bypass the vacuum diaphram.

 

but even with it in the prime position the carb will stop the fuel flow if its correct. other wise we wouldnt need floats