Fuel fill up vent to low

[-JR-]

I find on my 1986 Baylinner inboard that the vent for the fuel fill up is lower than the fill hole.
It is located About 3 feet to the left of the fill cap.
So when I fill up fuel ,i get fuel coming out of the vent and splashes out at the gas station drive way .
Because this happens the fuel pump handle will not click off first

Was thinking of raising this vent hole above the fill so this will not happen and this way the pump handle will click off when full.

Has anyone else done this? raising the vent
Is there a reason why it was installed Lower ?

 

[-JR-]

I find on my 1986 Bayliner inboard that the vent for the fuel fill up is lower than the fill hole.
It is located About 3 feet to the left of the fill cap.
So when I fill up fuel ,i get fuel coming out of the vent and splashes out at the gas station drive way .
Because this happens the fuel pump handle will not click off first

Was thinking of raising this vent hole above the fill so this will not happen and this way the pump handle will click off when full.

Has anyone else done this? raising the vent
Is there a reason why it was installed Lower ?

 

[harringtondav]

You have a standard arrangement. The vent is lower to allow excess fuel to escape before it reaches the top of the filler neck. I think this is a NMMA and USCG requirement. I wouldn't change it for safety.

I only take on enough fuel to get me through a typical day with with enough reserve to get me back to the ramp. That excess fuel just loads down a boat, and adds load trailering it home.

If you burn a full tank on a day you'll just have to be more careful and slow up the nozzle flow near the top.

 

[chevymaher]

LOL mine is the same level as the fill hole does the same thing. Start slowly and speed up slightly. Hold the handle and listen.

 

[dingbat]

Your situation has little to do with the vent location.

Fuel trapped in a low spot in the line running from the tank to the vent is usually to blame.

The vent line should be routed so there is a high spot between the vent and the tank with no low spots in between.

Remove line from vent and blow back to the tank. It should be clear.

 

[poconojoe]

I'm just wondering, for educational purposes, what is this vent that is 3 feet to the left of your fill cap? My Bayliner doesn't have that, but it's a bit newer (2003). Is it an actual fitting that is through the hull? Does my newer setup accomplish the venting differently? Maybe through the filler neck?
I never have an overflow or spillage problem at the gas station. The gas nozzle clicks off normally like filling my truck.

 

[dingbat]

I'm just wondering, for educational purposes, what is this vent that is 3 feet to the left of your fill cap? My Bayliner doesn't have that, but it's a bit newer (2003). Is it an actual fitting that is through the hull? Does my newer setup accomplish the venting differently? Maybe through the filler neck?.

The short answer is yes, the vent is built into the cap of the filler neck assembly.
If you look at the filler cap, at least on mine, you’ll see a one-way valve that vents to atmosphere

 

[harringtondav]

I'm guessing here. Gasoline fume control, and engine compartment spark avoidance are key safety goals in boat design standards. When you fill your tank, you displace the same volume of gas vapors. Cars capture a lot of this in their evap. canisters. But it goes right out the vent in boats. I'm thinking the low, side location of the vent is to keep the fumes as far as possible from the cockpit and engine box.