All the new "safe" fuel tanks suck. I haven't found one that worked for more than a month without breaking. Terrible designs, not safe at all.

 

No but I'm pretty sure the reason behind it is so the vapors don't escape into the atmosphere. Good example of more EPA goodness is the large gas caps on Honda gas tanks. There's a charcoal filter under the cap to "filter" the fumes passing thru the vent hole. If the gas gets sloshed around and soaks the filter, the tank doesn't vent and the motor stops running due to a vacuum in the gas tank.

 

I have one of the new tanks on my boat. It sits outside in the yard and the hot sun. It swells up pretty good. Every now and then, when I walk by it and think about it, I unscrew the cap a little to relieve the pressure. The paper that came with the tank said it was normal due to the cap design and to periodically unscrew the cap to relieve some pressure. Been in the sun all summer and has not burst open yet. I dont particularly like seeing it swelled up like a beach ball sometimes but it always returns to normal when I unscrew the cap.

 

I just finished reading Moeller FAQ on this issue and it says the cap is supposed to vent at 5psi, but the tank is designed to hold 15psi. I apparently missed the notice about swelling when I bought the tank. I have never noticed it swelling up very much when out fishing and it's stored indoors so was just not aware of a big swelling problem until now.

Anyway, with a new cap I won't be having this problem.

 

You can snip a little off the rubber flap on the cap to eliminate the problem

 

That's good to know. I already disposed of the original cap. Online a replacement for Moeller old style cap is about $9 to $10 and the new fangled cap is about $23 to $25.