spontaneous fuel system overflow

[dcschif]

does anyone have any suggestions as to why my boat would spontaneously overflow (dump) fuel from my overflow system when the boat is not in use. I know I have at least 3/4 or more fuel in the tank and I have not had the boat out for a couple weeks, tonight right about sunset, the boat started pouring at least 1-2 gallons of fuel on to my carport. There are at lease 50-60 gallons of fuel which include some fuel additives (octane) and some left over Sta-bil as well. Thanx for the help.

 

[Boomyal]

Re: spontaneous fuel system overflow

Heat expansion of the fuel plus improperly routed/configured vent line would be my guess.

 

[Boatist]

Re: spontaneous fuel system overflow

I agree but it can be just over filled. If it too full the fuel will block the vent line output as the heat builds up pressure builds in the tank until it is high enough to force fuel out the vent line. If it get hotter the next day it will do it again.

 

[newport dave]

Re: spontaneous fuel system overflow

When you say "overflow" do you mean the fuel tank vent?<br /><br />If you mean that the bilge pump pumped gas out into your carport, you have a serious situation there. <br /><br />Dave

 

[dcschif]

Re: spontaneous fuel system overflow

the vent line is 10 inches below the fill hole. what are my possible solutions. I am somewhat nervous about just dropping the boat in and starting it. I'd hate to go up like a firework! is this a bad situation or am i over-reacting and how do I keep this from reoccuring? thank you all for your thoughts and contributions.

 

[Dunaruna]

Re: spontaneous fuel system overflow

Just for clarification - did you say the vent outlet is 10 inches below the filler?<br /><br />Aldo

 

[RubberFrog]

Re: spontaneous fuel system overflow

Mine does this. My "solution" has been to loosen my fuel cap. The problem stops immediately. I'm sure someone else will know why.

 

[akriverrat]

Re: spontaneous fuel system overflow

i would bet that the vent outlet on the tank is below the level of the fuel in the tank due to the up or down angle of the boat on the trailer. level out the boat. but i wouldn't bet $.

 

[jeff13601]

Re: spontaneous fuel system overflow

How far above the top of the tank is the vent hole?