M_Boats: outboards

I know this must have been covered before but I'm a newbie. I'm planning on getting a 15 monty and I have a 8 hp Yamaha 2 stroke , would this be over kill for a 15ft . Or could I use it as my permanent motor . Cause I really like the motor and it weights about the same as most 4hp 4 strokes Thanks for any feed back Klaas