Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Fuel tank vent.
Posted by huckelberry145 on 05/10/14 - 1:03 AM
#1
Last summer, I had to buy a new Moller fuel tank because my original one got a crack in it. The new one doesn't seem to want to vent like the old one did much less like any other tank I have. Even though I have the vent open, I have to leave the cap loose so the tank doesn't blow up like a balloon during the hot afternoon and collapse at night. I even bought a new Moller gas cap for the tank and it does the same thing. Anyone else having these kinds of problems? Any solutions?
Posted by wing15601 on 05/10/14 - 8:11 AM
#2
There must be some kind of vent or when running the engine either it would starve for fuel or the tank would collapse. I wouldn't imagine the engine's fuel pump is strong enough to collapse the tank. Have you contacted Moeller?
Posted by Phil T on 05/10/14 - 2:18 PM
#3
The new EPA and CARB emissions regulations extended to portable fuel tanks and required a new cap design.
The "open" vent in the typical fuel tank cap is no longer allowed. The new caps only vents when the pressure in the tank exceeds a threshold (I think it is 5 psi). There is a manual release feature.
See the bottom 1/2 of this reference page at Moeller's site:
http://www.moellermarine.com/sites/mo..._Sheet.pdf
There have been hundreds of complaints about the new venting caps.
Edited by Phil T on 05/10/14 - 2:27 PM
Posted by huckelberry145 on 05/10/14 - 3:41 PM
#4
I should have known, a government agency. Thanks Phil.
Posted by Cape Fear on 05/11/14 - 6:16 PM
#5
I just bought a 9 gallon Moeller 620009LP, new cap style. Turning the cap clockwise till it clicks lets you know it's closed but if you turn it back counterclockwise, it will get to a point where pressure will release but the cap is still on... I guess this is what they call "manual vent(?). I think the little screw on top of the cap opens a vent that only releases pressure at 5psi. It's all still new to me but it seems like it will be necessary to turn the cap counterclockwise to vent old style.
Posted by huckelberry145 on 05/11/14 - 7:10 PM
#6
I guess I'll have to experiment with it some to figure it out.
Posted by Cape Fear on 05/11/14 - 7:52 PM
#7
There is a pressure relief tab below the cap that hits about 1/4 turn back. I guess you push that down to remove the cap the rest of the way.
Posted by butchdavis on 05/12/14 - 5:37 AM
#8
On my modern Tempo tank pushing down on the small vent screw releases the tank pressure. Of course the vent screw should be in the open position.