Filling with fuel issue

[freerider8]

So I wanted to check on here first before I start tearing stuff apart to find the issue. When I try and fuel my boat the fuel wants to spill out the fill opening as if it is full but the gauge only says half a tank or even less at times. I have to fill it very slow in order to put fuel into the boat. What could cause this issue aside from maybe a kink in the line? Is it possible that the vent line is clogged or something? Anyone else ever have this issue and what did you do to fix it? I have to take the rear seats out and maybe even the carpet since the lines go down inside to the under side. I have a inboard motor in my boat. It is a 88 Baretta.

 

[Augoose]

Clogged or blocked breather tube or the pump moves fluid at a rate where the feeder hose to the tank can't handle the volume. Different gas stations supply fuel at different rates. I avoid several high flow stations where the pumps click off automatically in my chevy. Low flow stations don't cause the issue for me and its only with that truck.

 

[ESGWheel]

Fuel gages can be inaccurate. Is this a new issue? Not sure how much need to tear apart but if a new issue, need to follow the hoses from end to end to make sure not newly crimped somehow and then go from there.

One neat device I absolutely love is the vent hose whistle. This device is spliced into your vent line 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. Now that I dock it, it still is useful at the waterfront gas stations but due to the rocking of the boat it will gurgling 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

 

[Scott Danforth]

My first thought is either a blocked fill line, or a blocked vent line

 

[ahicks]

If there is a dip/low spot in the vent line, that can make filling just as you describe. Line need to gravity feed towards the tank. Low spot hold fuel, acts just like it's totally blocked....

 

[mr 88]

In many cases you can take a rubber hose with a bigger diameter than the vent ftg , put it over that and blow into it. Should clear spider crap out and you should hear the gas burbling in the tank . Sometimes you get wasp dirt packed in there , weed wacker line pushed down the vent will clear that . At least by doing this you ruled that out as the issue or fixed it .

 

[Scott Danforth]

in addition to all the tips above

my old Avanti fuel fill line inner wall failed and acted as a flap valve. the only solution was to replace the 2' of hose

 

[freerider8]

In many cases you can take a rubber hose with a bigger diameter than the vent ftg , put it over that and blow into it. Should clear spider crap out and you should hear the gas burbling in the tank . Sometimes you get wasp dirt packed in there , weed wacker line pushed down the vent will clear that . At least by doing this you ruled that out as the issue or fixed it .

Thank you for this tip. I will try that and see if it helps.

 

[freerider8]

Thank you to everyone for the helpful tips. I am going to try some of them before I go crazy with tearing stuff apart to see what may be happening. I do feel like there is a blockage of some sort. I believe the fuel gauge works properly, also aware that they fail but the gauge can even read below a half tank and the issue will still be a problem. I have notices this issue ever since I purchased the boat a couple of years ago.