Trouble filling gas tank

jennis9

Petty Officer 1st Class
Joined
Mar 22, 2008
Messages
396
Having trouble filling the gas tank in our boat. 21' Starcraft openbow. The gas will go in then backup. We have to fill it very slowly.

We have blown out the air vent with canned air and have used a bottle cleaner on the neck of the tank. If there was as spider web in the first few feet, we would have cleared it.

Any ideas?
 

JoLin

Vice Admiral
Joined
Aug 18, 2007
Messages
5,146
Re: Trouble filling gas tank

Is this a new problem?

There isn't any magic bullet. You need to take the vent and fuel fill inspection a step or 2 farther. You don't say how old your boat is, but if it's 15 or more years old the fill/vent hoses are coming due for replacement anyway.

My .02
 

Thad

Lieutenant Junior Grade
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Jun 8, 2009
Messages
1,028
Re: Trouble filling gas tank

What do you mean by "canned air"? You need an air comperssor to achieve any "real" blow out. It sounds as if the vent is still obstructed.

The only other thing I can think of would be to try and find a station with a lower pressure gas line. Or do not try to fill it at full speed.

How long have you had the boat? Do you know if this has been an issue from the get go?

It just came to me. Another thing that it could be. My tank has a screen where the fill line fits the tank. If yours does, maybe it is plugged up with debris. There should be an access hatch under the enging hatch or bench seat. Would be worth looking into.
 

cshyde

Cadet
Joined
Jun 16, 2010
Messages
16
Re: Trouble filling gas tank

Worn hoses will eventually collapse. If your boat is pre-E10 Ethanol fuel and you have been using ethanol laced fuel the chances are that the ethanol had caused the hose to collapse. Also the tank may have shifted and is pinching one of the hoses. No matter what an inspection is needed. Open the access ports and look at the hoses and just replace them with new. What you don't want to have happen is a hose open up and leak while you are filling the tank. Obviously dangerous.
 
Joined
Mar 1, 2005
Messages
923
Re: Trouble filling gas tank

I bought a new boat last year and had similar problems immediately. It will fill normally but then gas will backup prior to the tank being full. Others told me a good trick, which is to pull the gas nozzle out of the filler tube every now and then to let the tank breath and little better. The gas settles down and now I don't get gas coming out of the filler neck.
 

jennis9

Petty Officer 1st Class
Joined
Mar 22, 2008
Messages
396
Re: Trouble filling gas tank

Thanks to all replies... answers are:

-- the boat is a 1985 Starcraft SuperSport
-- Yes, this is a new problem - we have been filling the tank VERY slowly
-- canned air was what one of the mechanics recommended, we did not use a compressor (but that is a good idea)
-- tank screen should be inspected and has not been prior to this posting

This is a new problem. Planning on opening the hatch and getting a better inspection. Luckily - it is an openbow and the tank is in the center of the deck.
 

oldjeep

Admiral
Joined
May 17, 2010
Messages
6,455
Re: Trouble filling gas tank

-- canned air was what one of the mechanics recommended, we did not use a compressor (but that is a good idea)

A compressor is NOT a good idea. The reason people use canned air is that you don't get static. Air from an air hose on a compressor can cause static discharges - which can make a big boom
 

jennis9

Petty Officer 1st Class
Joined
Mar 22, 2008
Messages
396
Re: Trouble filling gas tank

I prefer to remain in one piece - we'll be staying away from the compressor
 

seabob4

Lieutenant Commander
Joined
Jun 10, 2008
Messages
1,603
Re: Trouble filling gas tank

Your vent hose should run to the vent fitting with a loop that goes upwards then comes back down to the vent. Vent hose is typically soft walled, and as it ages, this loop can "collapse", causing a kink in the vent line.

You should have an inspection pie at the fuel fill. Remove it, find the vent line and trace its routing with your hand. You may find it is kinked...
 

Thad

Lieutenant Junior Grade
Joined
Jun 8, 2009
Messages
1,028
Re: Trouble filling gas tank

A compressor is NOT a good idea. The reason people use canned air is that you don't get static. Air from an air hose on a compressor can cause static discharges - which can make a big boom

Learn something new everyday. This one goes in the "things to remember" part of my head.:redface:
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Trouble filling gas tank

Your vent hose should run to the vent fitting with a loop that goes upwards then comes back down to the vent. Vent hose is typically soft walled, and as it ages, this loop can "collapse", causing a kink in the vent line.

You should have an inspection pie at the fuel fill. Remove it, find the vent line and trace its routing with your hand. You may find it is kinked...

A better idea is to route it straight as you can and install a fuel/air separator.

My bass boat burped on filling, and spilled fuel from the vent. This Parker Lg50 fixed it all. It comes with an additional right angle end for tight installs.
29977.JPG
 

seabob4

Lieutenant Commander
Joined
Jun 10, 2008
Messages
1,603
Re: Trouble filling gas tank

The loop is designed to keep the gas from running uphill. All builders do it, in fact, if I'm not mistaken, it's required by ABYC/NMMA...
 

jennis9

Petty Officer 1st Class
Joined
Mar 22, 2008
Messages
396
Re: Trouble filling gas tank

I believe my father calls this the 'drip loop' -- makes sense
 

j_martin

Admiral
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Sep 22, 2006
Messages
7,474
Re: Trouble filling gas tank

The loop is designed to keep the gas from running uphill. All builders do it, in fact, if I'm not mistaken, it's required by ABYC/NMMA...

The float valve in the lg50 does the same thing more reliably, and at the same time reduces vent back pressure (unless it's trying to flood) to 0. It works very well and has reduced my fuel contamination and loss to environment (except through the old smokey motor) to 0)
 

Stachi

Lieutenant Commander
Joined
Jul 14, 2009
Messages
1,671
Re: Trouble filling gas tank

The float valve in the lg50 does the same thing more reliably, and at the same time reduces vent back pressure (unless it's trying to flood) to 0. It works very well and has reduced my fuel contamination and loss to environment (except through the old smokey motor) to 0)

do you have a link for it ? Sounds like a good investment to me..
 
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