Challenger Fuel Vent breathes both ways

[IDoSeaDoo]

Hey all. I was curious about the fuel vent on the side of my Challenger. I took off the gas cap and tried to blow into it and was surprised to find that I could without any effort. Likewise I can inhale from it as well (I did not do that very long COUGH COUGH). Anyway, that seems pretty "not-right" to me, as I can picture water getting in there w/o problem when I carve right. How do I rectify this problem? It seems that there is something that should maybe screw onto it? Like a garden hose attachment but bigger diameter... I was thinking of buying one of those fuel vents off Amazon, but they don't seem to have a 1-way valve in them... Where does this valve go in this system?

Thanks!

 

[CaptSteve]

It is working as it should. It needs to vent both ways. When you file the tank, air needs to escape as the gas goes in. When you are running, air need to enter to replace the volume of gas as the gas is used. Do not put a one way valve in, otherwise you will either explode or implode the tank.

 

[IDoSeaDoo]

So then what keeps water from entering the fuel tank when I turn right and dip the boat onto its left side (submerging the vent)? Should there be something screwed onto the threaded part of the vent?

 

[CaptSteve]

There is a cap on the part that goes thru the hull. This cap has a screen and/or a slot that restricts the amount of water that can get in. Normally the slot points to the rear of the boat so that when you are going forward, the water is pulled away from the slot. If you have just a hole with no cap, you can get water in.

See here.

http://www.marineengine.com/products/accessory.php?in=2820506

I do not know if this is the exact part for your boat, but they all work the same way.

 

[rjcress]

So then what keeps water from entering the fuel tank when I turn right and dip the boat onto its left side (submerging the vent)? Should there be something screwed onto the threaded part of the vent?

When I looked at the system diagram and my vent cap here's what I thought:
The design of the cap on the vent is like a cup with slits in it. The small size of the slits should let very little water in.
The loop in the vent line should keep any water that makes it past the cap from making it to the fuel tank.
http://www.seadoopartscentral.com/fiche_section_detail.asp (set to "02 Fuel System", parts 10 & 12).
It looks to me that in order to get enough water in the vent line to push it past the loop, you would pretty much have to sink your boat.

 

[IDoSeaDoo]

Hmm, that makes sense. I wonder where my little screw on cup went... Maybe I can replace it with a generic from a boat store (hope the diameter matches.

 

[rjcress]

Hmm, that makes sense. I wonder where my little screw on cup went... Maybe I can replace it with a generic from a boat store (hope the diameter matches.

I saw one on eBay with Atwood branding... Or you can google the part number from the diagram.

 

[Stevego]

Hmm, that makes sense. I wonder where my little screw on cup went... Maybe I can replace it with a generic from a boat store (hope the diameter matches.

I had broke mine whe I hit Buoy. Replaced it with a bottle cap from a coke bottle and drilled a small hole in the center. Short term fix until you find new one.

 

[IDoSeaDoo]

I read somewhere that it's the same one Attwood sells, could someone take a pic of theirs so maybe I can buy to replace it with? Has anyone replaced theirs with one that's flush with the hull? Seems the ones I see on eBay taht are flush are too thin in diameter for the hole this baby is mounted through...