n00b carb ?

I did a carb swap in my 89 lx and so far most things have gone smooth. Although I have driven the car all of 1000km in 3 years. I had a stock 600 motorsport carb i had rebuilt but without the emissions crap. So far it has worked out alright.

My nQQb question is well very noobish. I was just wondering what those 2 tubes which stick out the top of the carb do. Are they vents? Are they supposed to hook to anything? It's a fairly pathetic question which I am sure I knew at one time but have no idea now. When I rev my stang, the engine makes a kind of hissing wind sound briefly before the rpm's climb and the nice rumble kicks in. Is this normal and if not qhat causes it?

John

Ok, so now that is answered what about the hissing sound. Again, when I first get off idle there is a hissing wind like sound comming from the carb. After you open the throttle a little more it goes away. Is this normal or is it a sign of a vacum leak or somthing?