The only difference is between my Yamaha 150 and a Yamaha 250 is a computer chip. All other parts are the same.
I’m not saying you are wrong….its highly likely you know more than I do, but wouldn’t the injectors have to be bigger? Seems it’d have to have more air also? Same motor, but with some slightly different parts? 100hp is a huge jump! Just my thought.
I’ve got a 2 stroke 40 Yamaha. I was told just changing out the carb could make it a 50 or 60. Then a carb and exhaust manifold?? (maybe that was the part) I could have a 70. They were the same motors though.
