Only relating what I read on this board. The bale is a manual fuel priming lever attached to the fuel pump. You work it by hand(up and down?) to get the air out of the pump and fuel into it.
I have a 3-5 psi electric fuel pump. Haven't had any issues with it yet.
More info here.
http://www.moyermarineforum.com/foru...hp/t-6769.html