That 225 is a BIG motor with a LOT more potential than the 225 sticker. I have a 1995 200 sitting in the garage and it's HUGE compared to the Mercury 2.5L that's right next to it . . . 2.4L Merc is even smaller. The 225 Evinrude is about the same physical size as a 250 Yamaha.
If I were you I'd lean toward a 2.4L or 2.5L merc v6 . . . I think it's a better combo for the 18.
