[jackman1939]

Thanks for your comments!
I am going to take the boat to the weigh station today. Just had the 100 hour checkup done on the engine. The mech said it was fine. It's a small dealership, and they don't have any equipment that hooks up to the Hondas to check whatever.
He also checked for full throttle and said it was wide open when the throttle lever (on the center console) was pushed all the way forward. The WOT stop on the throttle body is NOT adjustable - there is just a part on the TB that sticks out, and the rotating mechanism just hits it.
Yes, I am sure the speed is in MPH - I have a speedometer on the console and it reads about the same as the GPS.
I'll see if I can figure out how to disable one cylinder at a time.
The motor starts right up and runs very smoothly (at all speeds).
The mech said he thought it might be the hull??
Will report more after the weigh-in.