Check the nameplate - is 150 really the max HP rating? Seems low, but by '95 there were different Genmar models... If the max is 150, you could have some real problems with insurance if you try to go up to 225. If you are currently insured, you have to notify the company if you change the terms of insurability. Boat insurance covers a specified hull (HIN), motor (serial number), and/or trailer (title or VIN). The insurance company can dely a claim if you have changed the motor (especially going above nameplate rating!) and not notified them of the change. :(