Ron, A M-15 hull does not plane like a water skier. It is a displacement hull, which has a speed limit due to the laws of physics. A larger motor will not cause the boat to go faster. I guess I have the throttle open 60% on my 2hp Honda when my speed tops out. Also, a larger motor will put more weight on the transom. The bow will float higher, the stern lower. The center of lateral resistance of the hull will move aft. This can cause lee helm. It will also slow the boat. You may want to read up on lee helm and weather helm in a sailing book, or take a look here: http://www.sailingusa.info/sailboat_balance.htm As I mentioned in my other post, I sit as far forward in the cockpit as possible to balance the boat, and use a tiller extension.
From time to time you will find large motors on sail boats. I know of a father who purchased his daughter a 15 hp outboard for her 12 foot sailboat. The boat has been sailed only one time.
steve Steve R. M-15 #119 Lexington, KY -- Ron wrote:
Also , I thought I read somewhere that the pulpit adds strength to the transom hull-deck joint because of the through bolting of the stanchions, thus allowing a larger motor to be used without joint separation . Any input?
Ron