Fuel system issues

[Tipsy]

Recently purchased my first pontoon. It's a Sun Chaser 23', Has a Suzuki 115. Runs just fine, starts right away no troubles.
Permanent tank in back under sundeck. I filled it at the local gas station with non-ethanol gas before our first time out. Filling was a little slow going but I figured it was just because the fill was up high where I had difficulty getting the nozzle into the fill. Fast forward to a month later and I stop at the marina for my first fill-up there. The pump there kept shutting off and so I only got a small amount of gas. The dock guy said he could see the gas sitting in the filler line as if it was full.
I have checked everything.
The vent is clear.
The vent line is clear.
The vent check valve in tank is operating fine.
The vent carbon filter is clear with no restriction.
The filler door is fine.
The 1-1/2" filler hose is clear and straight down at an angle so no dips in it.
The filler check valve is clean and clear and operates great with no resistance at all.
When I removed the vent check valve from the tank I looked into the tank and all was clean.
Anyone have any ideas what else I can check? My next step is stopping at the marina again and see if it happens again.
Could it have been some sort of vapor lock fluke?
Thanks to all of you. I've been away for some time but I'm back now.
Jeff

 

[airshot]

Siphon some fuel from the bottom of the tank and check for water. Water in fuel is a popular problem. Many fuel stations don't keep up with the proper maintenence, so getting contaminants right from the start often happens.
I have saw where water comes in thru the vent line.....be sure the vent hose has in upward loop so any spray can't run back into the tank. Try taking a small sample of fuel when your filling your tank, test that for water or other contaminates. Do you have an inline water seperator/ filter....if not, time to install one.

 

[Scott Danforth]

Problems filling are either an obstruction in the fill line, or a blockage in the vent line

 

[Jeff J]

Checking the vent would be good. Was the vent check valve working when you pulled it?

It may also be that you had just the right angle when you to stretched to fill. Experiment with the depth and angle of the fill nozzle. My boat has been very picky about taking fuel since it was new. Modern pumps all seem to be either on or off. Trickling is no longer an option but I don’t have to if I can hit that magic angle. I have driven some road vehicles that required the nozzle be held at an odd angle to fill too. Generally speaking, flow has to be directed away from the vent. On my boat that means the nozzle is held inverted and not all the way in.

 

[jlh3rd]

could just be a "learning" process.
Gassed up my '06 pontoon last friday and you'd think I'd never gassed or owned a boat before.

 

[airshot]

Sorry did not catch the " filling" issue with your fuel system. Not unusual with boats and built in tanks. Often the main fill hose goes in awkward positions making filling difficult. The gas nozzles push fuel faster than the air can escape. My own fuel tank has that issue. It needs to be held at a slow filling speed or the trapped air creates pressure and overflows the fill neck. I have saw cases where two vent lines were used to help air escape, one vent line close to the tank where the fill hose attaches and another vent line further up closer to the fill cap. Some claim this helps alot......

 

[dingbat]

Make sure your vent line is clear.

Seen water accumulated at the “dip” in the line a number of times. A bit of compressed air clears it