Bogging after 25 MPH?

Last outing last year, gassed up on the lake, then maybe a 15 minute ride back to dock (weather suddenly spoiled the day). We putted around (5 MPH type of thing) for a while. When I throttled up, motor bogged after 25 MPH. I'm wondering if my 325 HP, which has always consumed regular grade fuel, coughed at the premium fuel. Marina dude explained that he had to switch to premium, as he only has one pump and so many boats require premium.

The shop didn't know what to think of my posing the octane question and intend on throwing some maintenance items at it (plugs, etc). 225 hours.

Comments appreciated. The boat is out of province and I have to lick this quick so as not to spoil the up coming vacay.

Your boat wont reject premium, it should perform better.

When the marine guy saying he had to switch to premium you could have a bad batch, or something. Low Octane makes the engine ping and lose power but not really a bog at a certain RPM.

You might try just fuel additives, they have one for water removal in the tank, STP is one brand I know of.

You might look into your fuel filter as the boat is 10 years old 25mph is in the high fuel demand, maybe the filter is clogging.
You don't have to replace your wires and plugs, those will normally give you more problems at low rps but it doesn't hurt to check them.

I would recommend pulling the wires, look at the ends make sure you don't see corrosion, pull the plugs make sure they aren't Black or corroded, also your distributor cap, rotor after 10 years I would expect that to be a item on the replace list.

Yea, it should run fine on premium. I'd definitely start with the fuel filter.