Gas tank vent & valve seat

[460Dave]

Why would a Southwind not have a gas tank vent? Should I add a vent or is the vent built into the gas filler cap? Isn't a gas tank vent a CG requirement?
Also I am looking for a spring "seat" for an exhaust valve on a 460 D3VE A2A head. This is the part that goes between the valve spring and the head. A used one is fine.
Thanks

[superdave013]

Most boats like that have vented gas caps. If you look at it you will see a small hole (about 1/8"). I drill a few more so it will flow better with a high po engine.

[Unchained]

I had problems from vented gas caps. My boat sits so low in the water that water was splashing over the gas caps and getting in the gas tanks causing the engine to shut down. The vent hole in the caps was quite small but it doesn't take much to cause problems. I had to plug the holes in the caps and vent at the top of the gas tanks.

[jroos]

I have a Southwind. Caps are your vents.