Why do the fuel tanks on a Cessna 150 have different types of vents?

Question

On a C150, one is vented through the cap, the other tank is vented underneath with a small pipe.

Why?

Thanks.

Answer 1

Actually, they are both vented through the small pipe underneath the left wing (there is a vent pipe which connects the two tanks together) and both fuel caps should be vented as well to provide backup ventilation.

Because the main vent is closer to the left tank on light Cessnas, they tend to burn fuel from the left tank faster.