2019 merc 40 running poorly after storage...

Hey all...finally took my boat out today for first time and found my new 40 hp 4 stroke mercury running horribly! Fresh fuel and all...started several times since I put it up in November...
Almost feels like its running on one cylinder...no power...poor idle...top speed feels like half of normal. Is there something I should be looking at here? Something simple maybe, or should I call bass pro and make an appointment. It's not even a year old and was fine last year. I'm assuming its covered under warranty if its something mechanical, but I'm guessing its fuel related...maybe filter or similar. Any thoughts guys?? Thank you...

Bring it in for warranty.. if you mess with it first, they might deny warranty.

You could check plugs but like Buzz said, if you break it you pay.

Dropped off Monday....returned Tues.
Apparently, the 3cyl spark plug was dead...
Everything else was fine...17 hrs on it and it had a dead spark plug. Mercury covered it..no charge,which is the best part. Ran around today and all was great. I'm glad for the advice I got from you guys...and took it to service at the dealership...