" I am confused, I have what i believe is a 1962 Evinrude Fastwin 18hp longshaft, Im looking for a new motor that performs as least as well or better that the 18 on my 82 Crestliner Commodore 14foot boat, it weighs about 300 pounds. I want to keep the motor light and its used strictly for fishing small water. A dealer i talked to says one of the new 4stroke 15 horse motors will out perform my old 18, because the old motor is rated at the flywheel and the new ones are at the prop? is this true? "