91' ZXR750 turned into a fuel fountain??

Hi all I'm back with another problem 
This time it's a bit more energetic! The bike is hooked up, all fluids and such are well.
BUT ...
There is fuel flowing at an amazing rate (i.e. it's bypassing the cylinders completely) from the carb fuel overflows. Both of them.
Now, before I take the carbs apart, is there something obvious I'm missing here? All lines are hooked up fine, the pump is running well and so on.
The bikes been sitting for a few months, but I put fresh fuel in...
Any thoughts would be much appreciated.
- Alex

This time it's a bit more energetic! The bike is hooked up, all fluids and such are well.
BUT ...
There is fuel flowing at an amazing rate (i.e. it's bypassing the cylinders completely) from the carb fuel overflows. Both of them.
Now, before I take the carbs apart, is there something obvious I'm missing here? All lines are hooked up fine, the pump is running well and so on.
The bikes been sitting for a few months, but I put fresh fuel in...
Any thoughts would be much appreciated.
- Alex