Well my fix with extending the vent tube up high to stop gas getting into it didn't work.
Symptoms:
2019 Greyhawk 30, gas tank 1/2 full.
1. I can pour in gas from a portable can as fast as it will go, no problem.
2. When filling at gas station it delivers about 1/2 gallon and clicks off with gas filling the entry. With gas nozzle all the way in or just at entry, same thing.
3. Completely disconnected the vent tube, same result.
4. Snaked a 1/2" rubber hose in the filling tube to test for blockage. After about 4 feet there was a resistance, presumably the 90 degree entry to the tank. After twisting and jiggling it got past the bend and went another 18" to the bottom of the tank.
4. Only thing left is the vent tube - - hit it with compressed air no problem, tank was building up pressure. (Not sure why the air would not come out the fuel entry path, perhaps there is a one-way valve?).
5. No visible kinks bends in the filler hose.
Well I can still use it but filling at a gas station with a 5 gallon can is going to take a long time
.
Drove 20 miles to Camping World where we purchased it.
They said "We don't work on fuel systems, and gave some idiotic advise about making sure the vent line was above the fill line."
I see now why this 2019 had only 3000 miles on it. I ain't no dummy, just severely frustrated, I maintained and operated a 71 ft steel ketch liveaboard for 14 years.