BIG Question - replace Yamaha 150 HP with Honda 225HP

[THEFERMANATOR]

If it were me, I would keep the YAMAHA unless you use the boat for 500+ hours a year. You can buy alot of gas for the extra coin you'll put out for a 4 stroker. If you don't use the boat enough, then you have essentially just spent all that money just to have a 4 stroke, not for any savings. And I hate to say it(as I am against YAMAHA's), that 150 YAMAHA is a solid engine. And your biggest fuel savings will be seen at idle-trolling speeds, but you already have a kicker to save fuel there. I would strongly consider saving some coin and sticking with your current engine.