Yamaha outboard fuel tank
 

I purchased a 20 hp yamaha outboard for my 14 ft fishing boat. The EPA designed fuel tank is a disaster. The venting of tank is horrible. During the recent hot spell the tank would blow up like a balloon eventually causing a major fuel leak where the fuel line connects to the tank. Smelly and dangerous to say the least. I spoke with the local dealer who shared my frustration. Yamaha solution is to remove the tank from the boat after every use. I dont know if this is unique to Yamaha but I just drilled a small hole through the gas cap to vent the tank, safer than a boat full of gas. Good job epa

Nope, your not alone! Same thing happens too me.. Makes quite a mess.. And a real pain in the ass!!

The irony is that these tanks are supposed to be good for the environment but are in fact very polluting. They are also very unsafe IMO.

You say the venting is horrible. My guess is there is NO venting.
A work around would be to keep it in shade to lower the rate of expansion, and open the fill once in a while to drop pressure. Better than having pressure over come the seal and having a leak that you don't control.
We used to remove our tank when we had portables. We'd keep it in shade and would know it made the boat less available to be "ahem" borrowed without permission.

Upon further research I learned that the gas cap vent is supposed to open when the pressure in the tank reaches 5 psi. I don't think it does. I just want the government to but out. We all have seen how much gas spills into the lake at local marinas. They don"t seem to care about that. The gov. Regulates toilets, light bulbs and now my outboard motor. Sorry for the rant.

Hope you don't mind me piggybacking on this thread. Big issue with the "new" epa portable utility 5 gallon tanks with their "better for the environment" pour spouts. I've spilled more fuel with those spouts in one use than I ever did in my lifetime with the old capped spout and vent. Glad I still have the older plastic version.