I run a 6hp Yamaha four on my 17 Stryker. While this will give you the power you'll need in most situations, I would do the 8 hp if I were to get a new kicker. The reason is that because of the stairstepped transom there are times that the prop just isn't deep enough in the water to be effective. I think more power would cure that. Other than that, I love my Yamahas... great mileage, no smoke, and the quiet is very nice.