Fuel vent

rasbury

So I come home today and I see what looks to be fuel coming down the side of the boat...first thought someone had been pulling a little fuel out..took the cap off and a lot of fuel came out...tank is 3/4 at best....100 degrees here...is there vent that is possibly clogged ? Lots of pressure in there...

Handymans342

it’s usually by the cap. Post a pic

rasbury

That's what I would have thought @Handymans342. There is one for the crapper tank but not the fuel tank- obviously it's not going to be in the bilge...there two holes in the cap...is that supposed to be the vent? How could the heat get it pumping out like that? Don't recall it ever doing g that before..

PickleRick

Are you on a trailer?  I just put in that new 63ish gallon tank, on the trailer i do good to push 40 where i park on an incline nose up. If i dumped in 50 gallons or more the moment it got hot shed start spewing.  I am pre charcoal canister so i can always smell fuel if i smell the vent.  Gas expands when hot.  They make summer and winter gas.  Think of a swollen gas can in the hot sun. 


Diesel better. 

rasbury

I guess but seems like it should vent...there are two holes in the cap...need to look and see if some bugs got in them I guess...don't like fuel coming out of anywhere except spent exhaust! And yes, on the trailer...

aero3113

@rasbury , the vent isn’t part of the cap but part of what the cap screws into. If you look at it from the engine room you will see the vent hose connected to it. Take the cap off then take the vent hose off the tank and blow air through to see if it’s clogged.

Aqua_Aura

Heck I forgot that the vent was built into the fill hose/cap assembly. The holes in the cap are for using a tool to tighten and loosen the cap. 

Ian

And the 2 holes are for the wrench.

aero3113

It looks like it’s doing what it’s supposed to do. Being on the trailer and the heat was a perfect combination for it to vent out.

rasbury

So it will vent around the cap and certainly not into the bilge then is that what your all saying? Sure would not want that fuel and gasses going into the bilge...

aero3113

Yes, that’s correct.

rasbury

Ok then, plenty of other stuff to worry about!

PickleRick

Like that crappy USA blend fuel eating your gel coat

Handymans342

PickleRick said:

Like that crappy USA blend fuel eating your gel coat

LOL

rasbury

I will level out the boat some...

Cableguy Greg

Like the others said, the vent in part of the fill and cap. The vent is the small line going into the rear of the fill. 

https://www.perko.com/catalog/fuel_system_components/926/vented_fill_for_1-1_2_hose_-_angled_neck/

Spyderweb

This is my 1st boat with gas vent built into fuel fill.  So I get that when adding fuel, with the cap obviously off, air from tank can vent out, making room for the gas.  But it seems once you put cap back on, with the o-ring to seal it, that vent can no longer release air, as fuel expands in the heat.  Isn’t that a problem?

Handymans342

Spyderweb said:

This is my 1st boat with gas vent built into fuel fill.  So I get that when adding fuel, with the cap obviously off, air from tank can vent out, making room for the gas.  But it seems once you put cap back on, with the o-ring to seal it, that vent can no longer release air, as fuel expands in the heat.  Isn’t that a problem?

Has to let air in too as the fuel is used

Spyderweb

So sounds like with the gas cap on, it doesn't really seal off the fuel vent?

rasbury

yep, that seems to be the story...