Fuel tank venting

[mr geets]

My pontoon boat has the fuel tank in the left rear (roadside for a car) and the filler is located with an opening that is at 90 degrees to the water. A pain to fill whether on the trailer or at a marina but also poorly vented. I thought of just putting a tee in the fuel filler line but am not sure what to put on the tee. Any ideas on venting?

 

[GA_Boater]

What do you mean by poor venting? Is the vent line clear and no mud dauber nests in the line?

 

[Lightwin 3]

You're right, those vertical fills do not vent well.

However, make sure your vent line has no sags in it. If it does, fuel can collect in it and hamper proper venting.

Putting a T in the line may help. However, It MUST also vent overboard.

 

[mr geets]

I thought of the TEE and am only concerned about gas fumes??

 

[HotTommy]

If your fill hose has a sharp bend in it, it may restrict the flow of fuel into the tank and make filling slow. This is not a vent problem. If you have a restricted vent, it is ok to add another one, but as was mentioned earlier, be sure that all vents take the gas fumes outside the boat.

 

[ahicks]

The bigger problem here is POURING gas into an opening that's 90 degrees to the water, correct? Or am I misunderstanding?

I've seen those installations on a pontoon boats, with no choice but to wonder what they were thinking! Not all of us have gas docks on our lake, and even those that do often don't want to pay the long dollar marinas get for gas. That leaves you no choice but to try and pour it in.

 

[mr geets]

You are right about the bone head designers that put the filler at 90 degrees. The fill/vent pipes look ok but the vent is tiny (1/4" guess) and exits along fill tube fill entry. I may try a tee type after all and see if it improves things.

 

[bansil]

Something to think about is if you add a t to fill tube, the vent will still above tank wont help much at all
gas going in and air going out will still use same hole it is now.

now adding a seperate vent for say 3/8 fuel hose vented to the outside would be a major help

 

[bansil]

A fuel rated bulkhead fitting with 3/8 barb could be installed real close to fuel sending unit so you have access to bulkhead nut, safety issue would be using drill to make hole, i would use an air drill or old tyme hand drill

check out summit etc for vents like differential ,transmission breathers etc that clamp onto hose