Re: Can I bore out a 60hp Evinrude?
Increasing speed is difficult to do with power alone. This is because the amount of drag any given hull/motor combination has goes up in proportion to the velocity squared. I.e. If you double the speed, the drag goes up by a factor of four. This is not only applicable to hull drag but also to air drag. So, as walleyehed states, minimise your hull drag by optimising the performance with the motor you currently have (Raising the motor, repropping if necessary to achieve the top end of your WOT range, trimming properly, putting your passengers in the optimum place in the boat, keep the boat dry etc, etc.) You can also minimise air drag: if fitted make sure your bimini is not acting like a parachute or air brake, get rid of excess rocket launchers, etc. To achieve an increase of 7 or 8 mph will take a fair bit of power because the drag increases so much... you'd need at least 30hp more IMO. 2 or 3 hp will make hardly any difference, but optimising your set up will.
