Fueling/Motor problems - would appreciace input

[mbo_1971]

Hey folks. So the last 2 times out, I have had what I believe is a fueling issue with my boat and am wondering if anyone has any thought before I put her in the shop.

Setup:
Boat - '83 SeaCraft 20' SuperFisherman (so we know thats not the problem)
Motor - 2001 Yami 200 HPDI
Fueling System - Yami 10micron fuel filter which has new 3/8" fuel supply from the filter to the fuel bulb (also brand new) and through to the motor. Fill, vent and supply hoses are brand new (alcohol-friendly). Supply from the tank is 1/4" hose
Tank is original as is the fuel pickup valve. Tank has been pressure tested and has no leaks

Symptoms
Issue does not surface until I have been running for a while - I run 3600 rpm for about 30 min to get from Harbor out to the mouth of the Patapsco. Both times I have had no issues until I hit the mouth of the river (or 30 min of somewhat hard running). Motor will choke on itself, sputter and then cut out. I can crank it back up and will start idle but under load/throttle up it will choke again. Both times as I have looked at the fuel bulb, it has been sucked flat. If I unscrew the filter, there is a great suction release but there is fuel in the filter. I would have thought that with a flat ball, there would have been no fuel in the filter. This said, it was not completely full. Filter was brand new first time and was replaced (thinking it was a clog issue) only to have the issue repeat itself. I have not dumped the contents of the filter into a jar to see if there is water in the gas.

Troubleshooting
I was thinking I would start by hooking up a remote tank past the current fuel bulb and run it directly to the tank. This should tell me if this is a motor or a fueling issue. From there, I would work my way back to the main tank by adding a piece of the fuel system each trial period to see if i can isolate the issue.

I think that the issue is either 1) too small a fuel hose from the filter the the fuel bulb and through to the motor or 2) a bad fuel pickup valve out of the main tank. That is the only piece of the fueling system that has not been R&R'd at this point.

Any thoughts/similar experiences would be helpful. Anything I could clarify, please let me know. I just put this reconditioned boat in the water and am dreadfully disappointed that I can not go fishing at this point. Thanks in advance for any assistance here.

Matt