Venting the fuel tank

[SgtMaj]

Quick question, do I need to vent an under-deck fuel tank with an outboard motor? If so, what would the set up to vent it look like?

 

[tashasdaddy]

Re: Venting the fuel tank

if the tank is not vented the motor cannot suck the fuel out of the tank. some fillers have are self venting, you have your fill hose and then a second hose, that attaches to the side of the fill fitting. then their is the separate vent, that is either in the splash well, on on the outside of the gunnel.
http://www.iboats.com/Perko_Combina...10245755--**********.838991058--view_id.39387

 

[SgtMaj]

Re: Venting the fuel tank

if the tank is not vented the motor cannot suck the fuel out of the tank. some fillers have are self venting, you have your fill hose and then a second hose, that attaches to the side of the fill fitting. then their is the separate vent, that is either in the splash well, on on the outside of the gunnel.
http://www.iboats.com/Perko_Combina...10245755--**********.838991058--view_id.39387

The first one makes perfect sense, though I hadn't thought of it before. The second one though, is that to vent fumes away from the tank/deck to make sure there's not any explosions?

 

[Woodnaut]

Re: Venting the fuel tank

If you decide to use a separate fuel tank vent you might consider locating it in the motor well. When I built my boat I put the vents on the side as far up as they would go and toward the rear of the boat. This eventually caused me all kinds of grief because of water spray impinging on the vent as I was cruising around. (Water in the tank + four stroke fuel injected engine = Work and money.) I relocated the vents to the motor well and life has been great ever since.

Nevertheless, I have seen plenty of boats with the fuel tank vents on the side. I have also seen small clamshell vents placed directly over the tank vents to prevent the spray from entering the tank vent. This apparently works well also.

 

[tashasdaddy]

Re: Venting the fuel tank

the reason for the vent in the splash well or outside the gunnel, is the fuel cap is tight and does not leak. a full tank, with the bow high, heat from the sun, the fuel expands, thus any over flow, goes outside the boat, rather than in the bilge.
here are several separate vents. http://www.iboats.com/Vents/dm/****...e.match--**********.556305225--view_id.238202

 

[Bondo]

Re: Venting the fuel tank

Ayuh,.....

I've found that the Big Secret to keeping Water out of the Tank is,......

The Line/ Hose has to go Uphill,+ then loop over, to go Down to the Tank......

I had a boat with Bad water problems,... When I pulled off the side panel,.. The hose went Straight Down to the tank,..... Put a Loop in it,+ No more Problem.....

 

[SgtMaj]

Re: Venting the fuel tank

So let me see if I've got this... it's not that I have to do both, I just have to do one or the other, right?

If that's the case, I'll just do the fill and vent cap.

 

[tashasdaddy]

Re: Venting the fuel tank

works for me. it needs to be placed, so if you have an overflow, when filling it does not go into the boat.

 

[SgtMaj]

Re: Venting the fuel tank

works for me. it needs to be placed, so if you have an overflow, when filling it does not go into the boat.

Yeah, that will be the difficult part.