Gas leaking from tank inlet

[timharper89]

New to me boat. 1997 232 captiva with a (I believe) gen VI 454 carbed motor. Got it home and it has sat for a few days and when I came home from work this morning I smelled gas as I walked past it then I saw this (see pictures). There are gas stains running down the boat and a dried pool on the ground. I haven't it has I since I test drove it and we ran it a good 30 minutes to test, so it doesn't seem like it could be over filled. It did get hot (for Michigan) a couple days. Any ideas?

Also, is this going to mess up my paint at all?

 

[dingbat]

New to me boat. 1997 232 captiva with a (I believe) gen VI 454 carbed motor. Got it home and it has sat for a few days and when I came home from work this morning I smelled gas as I walked past it then I saw this (see pictures). There are gas stains running down the boat and a dried pool on the ground. I haven't it has I since I test drove it and we ran it a good 30 minutes to test, so it doesn't seem like it could be over filled. It did get hot (for Michigan) a couple days. Any ideas?

Check the fuel tank vent hose.
Make sure to make sure it's not plugged up with insects or full of water.

Also, is this going to mess up my paint at all?

Boats are gel coated, not painted.
May discolor a bit but can be sanded out if worst comes to worst

 

[timharper89]

There are 2 hoses coming to this inlet. Is one of these supposed to be the vent hose or is it somewhere else?

 

[mike_i]

It's happened to me many times. I topped off the tank too much and when the weather got hot the gas expanded and the vent burped gas. Not I stop filling the tank as soon as the nozzle clicks, problem gone.

 

[timharper89]

It's happened to me many times. I topped off the tank too much and when the weather got hot the gas expanded and the vent burped gas. Not I stop filling the tank as soon as the nozzle clicks, problem gone.

Even after running for a half hour (mix of wot, cruise and idle) it would be too full?

 

[dingbat]

There are 2 hoses coming to this inlet. Is one of these supposed to be the vent hose or is it somewhere else? View attachment 388129

It could be....most vents are separate, but some like mine vent through
the cap.

Check to see if you have a separate vent fitting on the side of the hull.
If not, then that's your vent

Even after running for a half hour (mix of wot, cruise and idle) it would be too full?

Possible........
The tank must have air space above fuel level to vent properly.

If you filled all the way up, the tank was full and excess fuel is backed up in the fill hose.

My fill hose is 1.5" in diameter and almost 5 feet long....you could use a lot of fuel and still not have head space in the fuel tank.

 

[tpenfield]

Is the boat parked on level ground or is the bow slightly uphill?

Agree the vent may be clogged, but that may have shown up during the water test.

 

[timharper89]

It could be....most vents are separate, but some like mine vent through
the cap.

Check to see if you have a separate vent fitting on the side of the hull.
If not, then that's your vent

There are no other openings in the hull or houses from the tank that I could find. Did some digging and saw someone say the vent for their rinker was in the fill cap that looked just like mine.

Possible........
The tank must have air space above fuel level to vent properly.

If you filled all the way up, the tank was full and excess fuel is backed up in the fill hose.

My fill hose is 1.5" in diameter and almost 5 feet long....you could use a lot of fuel and still not have head space in the fuel tank.

So how would I avoid this in the future? I didn't fill the tank, so I'm not sure what process he did, but it seems with a large fill hose you would likely fill it up to the top of the tank before it kicked the nozzle off

 

[timharper89]

Is the boat parked on level ground or is the bow slightly uphill?

Agree the vent may be clogged, but that may have shown up during the water test.

It is parked in my driveway that is mostly level, with the bow down toward the road, but I'd say the nose is probably up a bit from the tongue jack

 

[dingbat]

There are no other openings in the hull or houses from the tank that I could find. Did some digging and saw someone say the vent for their rinker was in the fill cap that looked just like mine.

So how would I avoid this in the future? I didn't fill the tank, so I'm not sure what process he did, but it seems with a large fill hose you would likely fill it up to the top of the tank before it kicked the nozzle off

I have the exact same fill x 2.

Don't get me started how the fill can also "vent" (rain) water into the tank as well.

I have never had an issue. Then again, I don't fill up (92 gallons = #650) unless I plan to use the fuel within a couple of days.

Try to keep no more than 1/2 tank (#325) at any given time. Less weight to hull around and the fresh gas at each outing keeps moisture to bay

 

[timharper89]

I have the exact same fill x 2.

Don't get me started how the fill can also "vent" (rain) water into the tank as well.

I have never had an issue. Then again, I don't fill up (92 gallons = #650) unless I plan to use the fuel within a couple of days.

Try to keep no more than 1/2 tank (#325) at any given time. Less weight to hull around and the fresh gas at each outing keeps moisture to bay

I think I will also keep it less than full. 75 gallons is a lot. Provably usually only use that much in a season, granted that was my old 4.3 motor. I'm sure to see an increase in fuel consumption with my 7.4

 

[dingbat]

I think I will also keep it less than full. 75 gallons is a lot. Provably usually only use that much in a season, granted that was my old 4.3 motor. I'm sure to see an increase in fuel consumption with my 7.4

Unless I'm heading offshore to fish or destination boating, I typically burn 25-30 gallons a trip.

Half tank keeps the weight down yet gives a 50% reserve just in case

 

[tpenfield]

full tank + vapor pressure = overflow

 

[ESGWheel]

Since my tank is on the small side, I can easily go thru ½ in a day so I try to get a full tank. So, I installed a vent hose whistle. This device is spliced into your vent line where it starts to go vertical and whistles like heck when filling. When get a ‘gurgling whistle’, tank is full. When I used to trailer my boat, this was a rock-solid indicator to get a full tank with no spilling, ever. And no burping due to too full and hot sun. Now that I dock it, it still is useful at the waterfront gas stations but due to the rocking of the boat it will gurgle sooner depending on how much the boat is rocking. Regardless, I still get a good fill and the guys at the dock love it. Here is one on Amazon link

 

[Lou C]

If it vents thru the cap there may be something wrong with the venting function, I’d try replacing the cap.
I have the old style separate vent & never had that problem…

 

[ESGWheel]

There are no other openings in the hull or houses from the tank that I could find. Did some digging and saw someone say the vent for their rinker was in the fill cap that looked just like mine.

It does vent thru the cap. See this link for a detailed description of how it works