I have pair of Merc 575 sci. Just unwinterized today. Port engine is fine. Started starboard engine and everything was fine. Seawater pump working and watching water temp coming up. After a few minutes is started to sputter and died. Cranked again and engine would sputter but not run. Left it sit for a hour and tried it again. It initially started then died. Nothing sounds wrong. Cranks just fine and just sputters. Hook the scanner up to it and no faults. I think it may be ignition related. Coil went bad over the winter?
Oil looks normal.

Sounds like water in the fuel. Had the same thing happen on my 525SC after the first start in the Spring.
Water sep filter was 90% water. Had to take it off and dump it a few times before it cleared out.

Easy preliminary diagnostics for Fuel and spark.

Spark: $5 spark tester between a plug wire and plug will show you if you have spark.

Fuel: Remove flame arrestor and look for fuel coming out of injectors. The one of a few benefits of the external injector TBI system.

Spark tester available at all auto parts stores:

Ayuh,... I agree with Griff,... Sounds like it ain't gettin' any gas, when it does, it sputters,...

It was fuel issue. Good call

Sounds exactly like the issue I had last spring. Started and died, started and died, then no start.

... I forgot to open the fuel valves ! Was sweating for a minute on a busy ramp! haha!

Bad thing is I'll probably do it again this year!