Converting a 1987 25 hp yamaha to a 40 or 50 hp ???

[maxius]

Hi, I bought a boat with a 25 hp yamaha. I would like to know if it is possible to increase the power of this motor to 40 or 50 hp ? What are the parts that need to be changed ? and the price of those parts ?? Can explanations about the way of doing this be found on the web ? Regards from France. MC.

 

[rodbolt]

Re: Converting a 1987 25 hp yamaha to a 40 or 50 hp ???

nope<br /> the 40 and 50 are vastly different beasts. sorry

 

[WillyBWright]

Re: Converting a 1987 25 hp yamaha to a 40 or 50 hp ???

You could stack antoher powerhead on top. That would double your power. Johnnyrude did that with a racing Wankel (stack of 4) that left all competition in it's wake. It would be awfully difficult and I doubt your gearcase would tolerate it.