10 hp. to 15 hp conversion

[doublej]

I am looking for someone who knows how to change a 1959 sportwin 10 hp. to a 15hp. This motor was on a boat that I bought this weekend and I really wasn't interested in the motor but I only gave 250 bucks for the boat, motor and trailer. The boat was a nice little 1448 and the trailer only needs tires so I really wasn't to concerned about the motor. When I got home with the boat I put new gas in the tank and pulled on the motor twice and it fired up and purred like a kitten! It also has some slide thing on the throttle that starts to close the butterflys on the carb. as you open the throttle. This makes no sense to me? I was wondering if that might have been how Evinrude detuned the engine to rate it at 10 hp. If some of you old boat mechenics know anything about it I would really appreciate it. Thanks.

 

[CarlF]

I dont think you can do it with a motor that old, its probably built to run at 10 hp. Juicing it up could prove fatal.