I'm still new to carbureted engines, but I've see a few of them recently. The mostly consistent thing that I've seen in most stock carbs is that the filter housing has a pipe going from the front of it down to the lower part of the engine. Anyone know what the purpose of this is?

 

If there's only one small one, that tube is probably for PCV ventilation.

If you're thinking of a 2" or so diameter pipe that runs down the right side from the snorkel, that's the heat riser. Ducts hot air from around the exhaust into the intake to make warming up easier.

Stock carb engine will have something like 4 or 5 total connections from airbox to engine, total depending on year of build

 

+1.. Too much else to list thou. I say post a picture and we'll inform.

 

by his description, this is exactly what i was thinking he meant.